Avery  Architectural  and  Fine  Arts  Library 
Gift  of  Seymour  B.  Durst  Old  York  Library 


FRONTISPIECE 

Main  Drainage  and  Sewage  Disposal  Works  Proposed  for  New  York  City. 


MAIN  DRAINAGE  AND  SEWAGE  DISPOSAL 
WORKS  PROPOSED  FOR  NEW  YORK  CITY 
REPORTS  OF  EXPERTS  AND  DATA 
RELATING  TO  THE  HARBOR 


REPORT 

OF  THE 

Metropolitan  Sewerage  Commission 

OF  NEW  YORK 

Appointed  under  Chapter  639,  Laws  of  1906,  amended  by  Chapter  422,  Laws  of  1908, 
Chapter  200,  Laws  of  1910,  and  Chapter  332,  Laws  of  1913,  of  New  York  State 


APRIL  30,  1914 


GEORGE  A.  SOPER,  President 
JAMES  H.  FUERTES,  Secretary 
H.  deB.  PARSONS 
CHARLES  SOOYSMITH 
LINSLY  R.  WILLIAMS 


TO 


WTNKOOP  HALLENBECK  CRAWFORD  CO. 
NEW  YORK 


LETTER  OF  TRANSMITTAL 


New  York,  April  30,  1914. 

Honorable  John  Purboy  Mitchel,  Mayor  of  the  City  of  New  York, 
Executive  Chamber,  City  Hall,  New  York  City. 

Sir:  The  report  of  the  Metropolitan  Sewerage  Commission  which  is  submitted 
herewith  recommends  a  system  of  main  drainage  and  sewage  disposal  for  New  York 
City,  to  be  built  in  progressive  stages. 

This  report  is  the  third  bound  volume  issued  by  the  Commission  to  describe  its 
investigations  and  its  opinions  and  recommendations.  In  addition  there  has  been  issued 
a  series  of  seventeen  preliminary  reports  and  various  interim  reports,  copies  of  which 
have  been  distributed  among  the  officers  of  the  New  York  City  Government.  A  list  of 
the  reports,  with  the  dates  of  issue,  will  be  found  at  the  end  of  the  present  volume. 
There  is  also  appended  a  list  of  the  assistants  and  experts  employed.  The  membership 
of  the  Commission  has  remained  unchanged  from  the  reorganization  of  the  board  in 
January,  1908,  to  April  30,  1914. 

Respectfully  submitted, 
Metropolitan  Sewerage  Commission  op  New  York  : 

George  A.  Soper, 
James  H.  Fuertes, 
H.  DeB.  Parsons, 
Charles  Sooysmith, 
Linsly  R.  Williams. 


FOREWORD 


It  will  be  of  assistance  in  examining  the  following  report  to  note  that  it  is  divided 
into  four  parts. 

Part  I  is  a  summary  of  the  work  done  from  1906  to  1914. 

Part  II  describes  the  plans  for  main  drainage  and  sewage  disposal  works  which 
the  Commission  recommends  the  City  of  New  York  to  construct  for  the  protection  of 
the  harbor. 

Part  III  contains  reports  of  experts  consulted  by  the  Commission,  including  five 
critical  reports  and  four  reports  upon  special  topics,  together  with  digests  of  these 
reports  and  explanatory  matter  relating  thereto. 

Part  IV  contains  data  relating  to  the  protection  of  the  harbor,  including  analytical 
results  not  pi*eviously  published,  corrected  statements  with  respect  to  tidal  flow,  a  dis- 
cussion of  the  present  status  of  sewage  disposal  and  practical  examples  of  main 
drainage  and  sewage  disposal  works  of  various  large  cities. 


TABLE  OF  CONTENTS 


PART  I. 

SUMMARY  OF  THE  WORK— 1906-1914. 

PAGE 


The  System  Recommended   19 

Scope  and  Legal  Authority   20 

Work  Reported  to  May,  1910   22 

Work  Reported  from  May,  1910,  to  August,  1912   24 

The  Final  Report   25 

Experts  Consulted   26 

Need  of  Immediate  Action   27 


PART  n. 

PLANS  FOR  THE  PROTECTION  OF  THE  HARBOR. 


Chapter  I.    Preliminary  Considerations   31 

The  Possibility  of  Collecting  the  Sewage  to  a  Central  Point  for  Disposal   32 

Continuous  Discharge  at  Sea   35 

Discharge  at  Sea  on  Outgoing  Tidal  Currents   36 

Application  of  the  Sewage  to  Farm  Lands   37 

Intensive  Purification  of  the  Sewage   40 

Partial  Purification  on  an  Island  at  Sea   41 

Chapter  II.    The  Four  Principal  Drainage  Divisions  in  that  Part  of  the  Metropolitan  Sewerage  District  which  Lies 

in  New  York  State   44 

Quantity  of  Sewage  Entering  New  York  Harbor   45 

The  Four  Divisions  of  New  York  and  Their  Main  Characteristics   47 

The  Selection  of  Central  Points  for  Disposal   48 

Definiteness  of  the  Plans  and  Estimates   49 

A  Brief  Description  of  the  Four  Divisions: 

Lower  East  River,  Hudson  and  Bay  Division   51 

Upper  East  River  and  Harlem  Division   52 

Jamaica  Bay  Division   52 

Richmond  Division   54 

Chapter  III.    The  Upper  East  River  and  Harlem  Division: 

Topographical  Features  of  the  Division   55 

Separation  of  the  Division  into  Five  Parts  for  Main  Drainage  Purposes   56 

Points  for  Concentration  and  Discharge  of  the  Sewage   56 

Methods  of  Treatment   57 

Sites  for  Treatment  Works   59 

Outlets   62 


8 


TABLE  OF  CONTENTS 


Chapter  III. — Continued:  page 

Systems  of  Main  Drainage   62 

Areas,  Populations  and  Quantities  of  Sewage   70 

Preliminary  Estimates  of  Cost  of  Main  Drainage  Works   70 

Plate  I.    The  Upper  East  River  and  Harlem  Division  following  page  70 

Chapter  IV.    The  Richmond  Division. 

General  Description  of  the  Territory   71 

Separation  of  the  Territory  into  Subdivisions   73 

Outline  of  the  Proposed  Plan  for  Main  Drainage   75 

Main  Drainage  Systems   76 

Treatment  Works   85 

Cost  of  Main  Drainage  Works   88 

Plate  II.    The  Richmond  Division  following  page  88 

Chapter  V.    The  Jamaica  Bay  Division: 

Boundaries  of  the  Division   89 

General  Features  of  the  Division   89 

Probable  Future  of  Jamaica  Bay   90 

Probable  Future  Population  of  the  Division   92 

General  Outline  of  the  Proposed  Plan   92 

Summary   97 

Plate  III.    Profiles  of  Sewers  Leading  to  Treatment  Works  following  page  98 

Plate  IV.    The  Jamaica  Bay  Division  following  page  98 

Plate  V.    Profile  Jamaica  Interceptor  to  Main  Outfall  Tunnel  following  page  98 

Chapter  VI.    The  Lower  East  River,  Hudson  and  Bay  Division: 

Boundaries  and  Topographical  Features   99 

The  Existing  Sewers — Their  Outfalls  and  Resulting  Nuisances   102 

Possibility  that  the  Sewers  of  Manhattan  Will  Have  to  Be  Rebuilt   106 

Quantity  and  Composition  of  the  Sewage   109 

Possible  Methods  of  Sewage  Treatment   109 

Plan  Recommended  for  the  Disposal  of  the  Sewage  of  this  Division   113 

Collecting  the  Sewage  to  the  Outlet  Island   116 

Recommendation  of  the  Commission  as  to  the  First  Installation   124 

Plate  VI.    Profile  of  the  Manhattan  Interceptors  following  page  124 

Plate  VII.    Profile  of  the  Brooklyn  Interceptors  following  page  124 

Plate  VIII.    Profile  of  the  East  River  Siphon,  Force  Mains  and  Outfall  Tunnel  following  page  124 

Opinion  of  the  U.  S.  Engineers  on  the  Proposed  Island   125 

Separate  Screening  Plants   129 

Alternative  Projects  for  Disposing  of  the  Sewage  of  the  Lower  East  River,  Hudson  and  Bay  Division .  .  .  130 

Plate  IX.    Data  Relating  to  the  Lower  East  River,  Hudson  and  Bay  Division  following  page  138 

Chapter  VII.    Form  of  Administration  Recommended  for  the  Protection  of  New  York  Harbor  Against  Excessive 
Sewage  Pollution: 

Introductory   140 

Questions  Raised  by  the  Legislature  and  Answers   142 

I.    An  Interstate  Supervisory  Commission   143 

II.    A  Constructing  Commission  for  New  York   146 

Plate  X.    The  Order  in  Which  it  is  Suggested  that  the  Works  be  Built   150 


TABLE  OF  CONTENTS  9 
PART  III. 


REPORTS  OF  EXPERTS  CONSULTED  BY  THE  COMMISSION. 

PAGE 

Chapter  I.    Critical  Reports  on  the  Commission's  Projects: 
Introduction : 

I.    Introductory   153 

The  Oxygen  Question   153 

Project  for  the  Protection  of  the  Lower  East  River   155 

II.    Synopsis  of  the  Experts'  Reports   158 

Reports  of  Messrs.  Fowler  and  Watson   158 

Reports  of  Messrs.  Fuller  and  Hering   161 

Report  of  Mr.  George  E.  Datesman   165 

III.    The  Commission's  Opinion  with  Regard  to  the  Experts' Reports   167 

Critical  Reports: 

Section  I.    Report  of  Gilbert  J.  Fowler,  D.  Sc   173 

Immediate  Conclusions   173 

Principles  Governing  Consideration  of  the  Problem   174 

The  Present  Polluted  Condition  of  the  Harbor   177 

Proposed  Remedies   178 

Summary  and  Conclusions   181 

Section  II.    Report  of  John  D.  Watson,  C.  E   182 

The  Polluted  Condition  of  the  Harbor   182 

Discussion  of  the  Metropolitan  Sewerage  Commission's  Four  Schemes  for  the  Purification  of  the 

Harbor   185 

Scheme  1.    Application  of  the  Sewage  to  Land   186 

Scheme  2.    Oxidation  in  Bacteria  Beds  ,   187 

Scheme  3.    Local  Treatment  Works  and  Outfalls   188 

Scheme  4.    Conveyance  of  a  Large  Part  of  the  Sewage  to  Sea   189 

Need  of  a  Permanent  Sewage  Disposal  Commission   191 

Necessity  for  Immediate  Action   192 

Section  III.    Report  of  George  W.  Fuller,  C.  E   193 

Brief  Summary  of  General  Conclusions   194 

Basis  of  Study   195 

Influence  of  New  York  Sewage  on  the  Waters  of  the  Harbor  and  Vicinity   195 

Proposed  Standards  of  Cleanness   196 

Metropolitan  Sewerage  Commission's  Program   197 

General  Endorsement  of  Commission's  Program  as  above  Stated   198 

Undesirability  of  Deep-Sea  Disposal  at  a  Central  Point   200 

Undesirability  of  Applying  the  Sewage  of  New  York  City  to  Sewage  Farms  on  Long  Island   201 

Impracticability  of  a  Central  Plant  to  Treat  All  the  Sewage  of  New  York  City  by  Intensive 

Purification  Methods   203 

Synopsis  of  Program  Adopted  by  the  Commission   204 

Efficiency  of  Methods  of  Sewage  Treatment   206 

The  Significance  of  the  Digestion  of  Sewage  Sludge  and  the  Absorption  of  Dissolved  Atmospheric 
Oxygen  in  Sludge  Decomposition   206 

Probable  Future  of  Various  Sewage  Treatment  Methods   208 

Conclusions  as  to  Program  being  Considered  by  the  Commission   212 

A.  Agreement  on  Clarification  Program   212 

B.  Opinion  as  to  Outlet  Island   212 

Appendix  to  Mr.  Fuller's  Report: 

Memorandum  of  Views  in  Opposition  to  the  Proposed  Standard  of  a  Minimum  Dissolved 
Oxygen  Content  of  Three  Cubic  Centimeters  per  Liter  of  New  York  Harbor  Water   213 

Correspondence  Containing  Mr.  Fuller's  Endorsement  of  the  Commission's  Recommendation  for 
the  Gradual  Construction  of  the  Lower  East  River  Project: 

Letter  of  the  Commission  Suggesting  Certain  Changes  in  the  Program  of  Construction  for  the 

Lower  East  River  Project   218 

Letter  of  Mr.  Fuller  Concurring  with  the  Commission's  Amended  Program   219 


10 


TABLE  OP  CONTENTS 


Chapter  I. — Continued:  page 

Section  IV.    Report  of  Rudolph  Hering   220 

Introductory  Remarks   220 

Final  Disposition  of  the  Metropolitan  Sewage   223 

A.  Decomposition  by  Oxidation   224 

B.  Decomposition  in  the  Absence  of  Sulphur  Bacteria   227 

New  York  Harbor  Conditions: 

1.  Investigations  Made  by  the  New  York  Metropolitan  Sewerage  Commission   228 

2.  Currents  and  Tides   229 

3.  Sewage  Discharge   229 

4.  Floating  Matter   231 

5.  Sludge   232 

6.  Dissolved  Oxygen   234 

Experiences  Elsewhere   238 

Recommendations  of  the  Commission   240 

1.  Hudson  River   241 

2.  Upper  East  River  and  Harlem   242 

3.  Jamaica  Bay   243 

4.  Richmond   244 

5.  Lower  East  River   245 

Resume1  and  Conclusions    250 

Correspondence  Containing  Mr.  Hering's  Endorsement  of  the  Commission's  Recommendation  for 

the  Gradual  Construction  of  the  Lower  East  River  Project: 
Letter  of  the  Commission  Suggesting  Certain  Changes  in  the  Program  of  Construction  for  the 

Lower  East  River  Project   253 

Letter  of  Mr.  Hering  Concurring  with  the  Commission's  Amended  Program   254 

Section  V.    Report  of  George  E.  Datesman,  C.  E   255 

Present  Conditions   256 

Future  Conditions   256 

Comparison  with  Other  Cities   257 

Governing  Factors  for  Final  Disposal   257 

Methods  of  Treatment  Studied  by  the  Commission   258 

1.  Submerged  Outlets   258 

2.  Floatation  Chambers   259 

3.  Grit  Chambers  with  Screens   259 

4.  Land  Treatment   260 

5.  Percolating  Filters   260 

6.  Locally  Placed  Tanks  261 

Types  of  Tanks: 

a.  Emscher  Tanks   262 

b.  Dortmund  Tanks   263 

c.  Plain  Sedimentation  Tanks   263 

d.  Tanks  Subject  to  Tidal  Influence   263 

7.  Removal  of  the  Sewage  to  the  Upper  Bay   264 

8.  Removal  of  the  Sewage  to  an  Island  at  Sea   265 

The  Commission's  Project   265 

The  Principle  of  Gradual  Construction   267 

Precedent  for  Removal  of  Sewage  to  a  Distance  for  Treatment   26S 

Features  of  Design   268 

High  and  Low-Level  Interceptors   269 

Connections  with  Interceptors   269 

Suggestions  Applicable  to  New  York   270 

Conclusion   272 


Chapter  II.    Reports  on  Special  Topics: 

1.    Relation  Between  the  Disposal  of  the  Sewage  and  the  Death  Rate,  and  a  Report  by  Walter  F.  Willcox 
on  the  Crude  and  Corrected  Death  Rates  of  New  York,  London,  Berlin  and  Paris  for  the  Ten  Years, 


1900-1909   273 

The  Unsatisfactory  Conditions  of  Sewage  Disposal   274 

Possibility  of  Reducing  the  Death  Rate   275 

Report  of  Walter  F.  Willcox   277 

Appendix   281 


TABLE  OF  CONTENTS 


11 


Chapter  II. — Continued:  page 

2.  Chemical  Oxidation  as  a  Process  of  Sewage  Treatment  and  a  Report  by  Samuel  Rideal  on  Oxidation 
Processes  Applicable  to  New  York  Conditions   287 

Aeration  and  Chemical  Oxidation  Compared   287 

Intended  Scope  of  Dr.  Rideal's  Report   288 

Synopsis  of  the  Report   289 

The  Commission's  Opinion   291 

Report  of  Samuel  Rideal   292 

Estimation  of  the  Amount  of  Chlorine  Required   295 

Provision  for  Increase  of  Population   297 

Amount  of  the  Present  Aeration  by  River  Water   299 

3.  Purification  which  can  be  Effected  by  Settling  Basins  and  a  Report  by  Karl  Imhoff  upon  the  Use  of 
Emscher  Tanks  in  Purifying  New  York  Harbor   301 

Types  of  Tanks   301 

Sedimentation  Tanks  and  Efficiency   302 

Disposition  of  Sludge  and  the  Emscher  Tank   303 

Synopsis  of  Dr.  Imhoff 's  Report   305 

Comments  by  the  Commission  on  Dr.  Imhoff  s  Report   307 

Report  of  Karl  Imhoff   313 

4.  Discharge  of  Sewage  into  the  Harbors  of  Boston  and  New  York  and  a  Report  by  X.  H.  Goodnough  on 

the  Conditions  which  Led  to  the  Construction  of  the  Main  Drainage  System  of  Boston  and  Vicinity ....  320 

Similarity  Between  Former  Conditions  in  Boston  and  Present  Conditions  in  New  York   320 

Essential  Features  of  the  Boston  and  Metropolitan  Works   321 

Present  Sanitary  Condition  of  Boston  Harbor   322 

Report  of  X.  H.  Goodnough   324 

Summary   328 

The  Boston  Main  Drainage  System,  the  Purpose  for  Which  it  was  Designed  and  the  Results 

Achieved   328 

Metropolitan  Sewerage  Systems  and  Reasons  which  Led  to  their  Construction   331 

South  Metropolitan  Sewerage  System   33 1 

Effect  of  the  Discbarge  of  Sewage  at  Moon  Island   332 

Result  of  Numerous  Investigations  of  the  Effect  of  the  Discharge  of  Sewage  at  the  Moon  Island 

Outlet  335 

Effect  of  the  Discharge  of  Sewage  at  Deer  Island   335 

The  Outlet  of  the  High-Level  Sewer  at  Peddock's  Island   336 

Summary  of  the  Results  of  the  Discharge  of  Sewage  at  the  Three  Principal  Outlets  in  Boston 

Harbor   337 

General  Effects  of  the  Discharge  of  Sewage  at  the  Various  Outlets   338 

PART  IV. 

DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR. 

Chapter  I.    The  Utilization  of  Sewage  with  Special  Reference  to  the  Possibility  of  Deriving  a  Financial  Return 

from  the  Sewage  of  New  York  City   341 

Composition  of  Sewage  with  Reference  to  Utilization   341 

Origin  and  Variable  Quality  of  the  Mixture   342 

The  Liquid  Portion   343 

The  Solid  Ingredients   343 

The  Gases   344 

The  Mineral  and  Organic  Matters   344 

The  Bacteria  and  Other  Forms  of  Life   345 

Natural  Changes  which  Sewage  Matters  Undergo  in  the  Presence  and  Absence  of  Air   346 

Septicization   347 

Composition  of  the  Standard  Sewage  Assumed  for  New  York   347 

The  Question  of  Utilization   348 


12 


TABLE  OF  CONTENTS 


Chapter  I. — Continued: 

The  Nitrogen  Problem :  page 

Importance  of  Nitrogen   351 

Consumption  of  Nitrogen  Compounds  in  Agriculture  and  in  the  Arts   351 

Main  Sources  of  the  Nitrogen  Compounds   352 

Natural  Sources   352 

Chili  Saltpeter   352 

Saltpeter   352 

Guano   353 

Coal   353 

Peat  and  Silt   353 

City  Refuse   353 

Artificial  Sources   354 

Mond  Gas   354 

Human  Excrement  versus  Other  Fertilizers   354 

Factors  Influencing  the  Value  of  Fertilizers   355 

Stability  on  Storage   356 

Transportation   356 

Convenience   356 

Competition  with  Artificial  Fertilizers   357 

Most  Desirable  Constituents  of  Fertilizers   357 

Function  of  the  Soil   357 

The  Most  Needed  Compounds   358 

The  Composition  of  Human  Excrement   360 

Analyses  of  Feces  and  Urine   360 

Practical  Attempts  to  Utilize  Sewage   362 

Poudrette   364 

Compost   365 

Utilization  Through  Farming   366 

Proper  Soils  for  Sewage   367 

Capacity  of  Farm  Land   368 

Method  of  Applying  the  Sewage  to  the  Land   370 

Ridge  and  Furrows   370 

Preliminary  Treatment   371 

The  Interests  of  Sanitation  and  Agriculture  Opposed   371 

Factors  Affecting  Results  Obtained  by  Sewage  Irrigation   371 

Climate   371 

Sanitary  Considerations   372 

Sociological  Conditions   372 

dope   373 

Nuisances  from  Odors   373 

Examples  of  Sewage  Farms   374 

American  and  European  Conditions  Compared   378 

Financial  Results   379 

Authoritative  Opinions  with  Regard  to  Irrigation   380 

Considerations  Affecting  New  York   384 

Recent  Official  Opinions  on  Utilization   384 

Opinion  of  Dr.  H.  MacLean  Wilson   385 

Opinion  of  Mr.  H.  W.  Clark   387 

Sludge   388 

Chemical  Composition   390 

Volume  and  Weight   390 

Disposal  of  Sludge   392 

Irrigation  with  Wet  Sludge   392 


TABLE  OF  CONTENTS 


13 


Chapter  I. —Continued:  page 

Pressed  Sludge   394 

Worcester,  Mass   394 

Providence,  R.  1   395 

Glasgow,  Scotland   395 

Bradford,  England   395 

Spandau,  Germany   395 

Cost  of  Pressing   396 

Centrifugalized  Sludge   397 

Hanover   397 

Frankfort   397 

Drying  Sludge  by  Heat   398 

Glasgow   398 

Bradford   399 

Kingston-on-Thames   399 

Destructive  Distillation  of  Sludge   400 

Production  of  Fertilizers   400 

Recovery  of  the  Grease  in  Sludge   404 

The  Use  of  Sludge  as  Fuel   406 

Production  of  Gas  from  Sludge : 

Gases  Produced  by  Decomposition   408 

Recovery  for  Utilization   410 

Financial  Results   412 

Chapter  II.    Principles  of  Main  Drainage  and  Sewage  Disposal  Applicable  to  New  York,  with  Examples  Drawn 
from  Other  Large  Cities : 

Main  Drainage   414 

Terms  and  Assumptions  Used  by  the  Commission   415 

Storm  Water   418 

Sewage  Disposal   421 

Mechanical  Processes   423 

1.  Fine  Screens   423 

2.  Grit  Chambers   425 

3.  Sedimentation  Basins   426 

4.  Chemical  Precipitation   429 

5.  Other  Processes   430 

Biological  Processes   431 

1.  Broad  Irrigation   431 

2.  Intermittent  Filtration   432 

3.  Contact  Beds   432 

4.  Percolating  Beds   433 

5.  Other  Processes   434 

Disinfection   435 

Sludge  Disposal   436 

Examples  of  Main  Drainage  of  Other  Large  Cities: 

Baltimore   436 

Boston   438 

Chicago   439 

Columbus   442 

Providence  '   444 

Washington   445 

Worcester   446 

Berlin   449 

Cologne   452 

Dresden   453 

Essen   455 

Frankfort   457 

Hamburg   458 


14 


TABLE  OF  CONTENTS 


Chapter  II. — Continued:  page 

Copenhagen   460 

Vienna   462 

Paris   464 

Birmingham   466 

Glasgow   468 

Leeds   471 

London   473 

Salford   477 

Sheffield   480 

Chapter  III.    Rainfall  and  the  Relations  Between  the  Volumes  of  Domestic  Sewage,  Storm  Water  and  Tidal 

Water  in  New  York  Harbor   482 

Allowance  for  Storm  Water   483 

Intensity  of  Rainfall   485 

Example  of  a  Severe  Rainfall   490 

Ratios  of  Sewage  to  Water  in  the  Harbor   493 

Chapter  IV.    Tidal  Currents  in  New  York  Harbor  as  shown  by  Floats: 

Records  of  Observations  from  1907  tol913,  Inclusive   501 

Scope  of  Work   501 

Method  of  Work  in  1913   502 

Floats  .'   603 

Unsuccessful  Attempts  to  Use  Current  Meters   504 

Collection  of  Data   506 

Plotting  the  Data   507 

Results   507 

Conclusions   509 

The  Float  Records   513 

\ 

Chapter  V.    Tidal  Information  in  Possession  of  the  Commission  and  Correspondence  on  this  Subject  with  the 
United  States  Coast  and  Geodetic  Survey: 

Tidal  Studies   545 

Explanation  of  Methods  Employed   546 

Correspondence  with  the  United  States  Coast  and  Geodetic  Survey  in  Regard  to  the  Tidal  Phenomena. . . .  549 

Part  I.    Correspondence  Relating  to  the  Tidal  Flow   550 

Exhibit  I.    Letter  of  Commission  Requesting  Information  as  to  Instruments  and  Methods  of 

Measuring  Tidal  Flow   550 

Exhibit  II.    Letter  of  Coast  Survey  Giving  Information  Regarding  Measurement  of  Tidal  Flow, 

and  Offering  Results  of  their  Own  Observations   551 

Exhibit  III.    Letter  of  Commission  Submitting  Ten  Questions  Relating  to  Tidal  Flow   554 

Exhibit  IV.    Letter  of  Coast  Survey  Replying  to  the  Ten  Questions  of  the  Commission   557 

Exhibit  V.    Letter  of  Commission  Requesting  Further  Information  Upon  Flow  of  East  River. . .  .  574 

Exhibit  VI.    Letter  of  Coast  Survey  Furnishing  Further  Information  Upon  Flow  of  East  River. .  575 

Part  II.    Correspondence  Relating  to  New  Estimates  of  the  Flow  of  the  East  River   581 

Exhibit  VII.    Letter  of  Commission  Transmitting  New  Computations  of  Flow  in  East  River  and 

Requesting  Criticism  of  Same   581 

Exhibit  VIII.    Report  of  E.  F.  Robinson,  Assistant  Engineer,  on  New  Computations  of  Flow  in  the 

East  River   582 

Exhibit  IX.    Criticism  by  Coast  Survey  of  New  Computations  of  Flow  in  the  East  River   589 

Conclusion   593 

Part  III.    Correspondence  Relating  to  the  Probable  Stability  of  an  Artificial  Island   594 

Exhibit  X.  Letter  of  Commission  Requesting  Opinion  as  to  Stability  of  Proposed  Outlet  Island  594 
Exhibit  XI.    Notes  from  the  Coast  Survey  Upon  the  Probable  Stability  of  Proposed  Outlet  Island 

in  Lower  New  York  Bay   595 

Currents  at  Entrance  to  Lower  New  York  Bay   595 

Rate  of  Influx  into  Lower  Bay,  New  York   597 


TABLE  OF  CONTENTS 


15 


Chapter  V. — Continued:  page 

Sandy  Hook  Section   597 

Winds   598 

Direction  of  Wave  Travel   599 

Depth  to  which  Wave  Action  Extends   599 

Depth  at  which  Waves  Break   600 

Coastline  and  Depth  Changes   600 

Matter  in  Suspension   601 

Accumulation  of  Sand  at  the  Ends  of  the  Island   601 

Suggestions  Concerning  the  Location  of  the  Island   602 

Breakwater  Designing   602 

Permanency  of  a  Proposed  Island   603 

Chapter  VI.    Digestion  of  Sewage  by  the  Harbor  Water  and  the  Exhaustion  of  Dissolved  Oxygen,  with  Tables 
of  Oxygen  and  other  Chemical  Results: 

Section  I.    General  View  of  Analytical  Work  Relating  to  New  York  Harbor   607 

Section  II.    Digestion  of  the  Sewage  by  the  Harbor  Waters  and  the  Exhaustion  of  the  Dissolved  Oxygen: 

Digestion  of  Sewage  in  New  York  Harbor   612 

Composition  and  Quantity  of  the  Sewage   614 

Sludge  Deposits   616 

Conditions  Necessary  for  Final  Disposition   617 

Amount  of  Oxygen  Present  in  Unpolluted  Waters   619 

Sources  of  the  Dissolved  Oxygen   620 

Oxygen  as  a  Measure  of  Pollution   626 

Insufficiency  of  Oxygen  as  a  Criterion  of  Pollution   628 

Extent  to  Which  the  Digestive  Capacity  may  be  Utilized   629 

Calculation  of  Dilution  Required : 

Dilution  Required   631 

Oxygen  Required   632 

Calculations  of  Dilution   633 

State  of  the  Harbor  with  Respect  to  Dissolved  Oxygen  from  1911  to  1913   634 

Summary  of  Facts  Established  to  November,  1911   636 

The  Increasing  Exhaustion  of  Oxygen   638 

Essential  Facts  Relating  to  the  Cross-Sections   642 

Summary  of  Details  Relating  to  Special  Localities   643 

Section  III.    Tables  of  Dissolved  Oxygen  in  the  Water: 

Introduction  to  Tables  CXVI,  CXVII,  CXVIII  and  CXIX   647 

Table  CXVI.    Average  Volume  and  Percentage  of  Saturation  of  Dissolved  Oxygen  in  the  Water 

in  the  year  1911.    Averages  for  Various  Parts  of  the  Harbor   648 

Table  CXVII.    Average  Volume  and  Percentage  of  Saturation  of  Dissolved  Oxygen  in  the  Water 

in  the  year  1911.    Averages  of  Samples  Taken  at  Surface,  Mid-Depth  and  Bottom  for  Various 

Parts  of  the  Harbor   649 

Table  CXVIII.    Average  Volume  and  Percentage  of  Saturation  of  Dissolved  Oxygen  in  the  Water 

in  the  year  1911.    Averages  of  Samples  Taken  on  Ebb  and  Flood  Currents  for  Various  Parts 

of  the  Harbor   653 

Table  CXIX.    Average  Volume  and  Percentage  of  Saturation  of  Dissolved  Oxygen  in  the  Water 

in  the  year  1911.    Summary  of  Tables  CXVI,  CXVII,  CXVIII   654 

Oxygen  Map  A  following  page  654 

Introduction  to  Tables  CXX,  CXXI,  CXXII,  CXXIII  and  CXXIV   655 

Table  of  Contents  for  Table  CXX   656 

Table  CXX.    Volume  and  Percentage  of  Saturation  of  Dissolved  Oxygen  in  the  Water  in  the  year 

1912   656 

Table  CXXI.    Average  Volume  and  Percentage  of  Saturation  of  Dissolved  Oxygen  in  the  Water  in 

the  year  1912.    Averages  for  Various  Parts  of  the  Harbor   667 

Table  CXXII.    Average  Volume  and  Percentage  of  Saturation  of  Dissolved  Oxygen  in  the  Water 

in  the  year  1912.    Averages  of  Samples  Taken  at  Surface,  Mid-Depth  and  Bottom  for  Various 

Parts  of  the  Harbor   668 


16 


TABLE  OP  CONTENTS 


Chapter  VI. — Continued:  page 

Table  CXXIII.  Average  Volume  and  Percentage  of  Saturation  of  Dissolved  Oxygen  in  the  Water 
in  the  year  1912.  Averages  of  Samples  Taken  on  Ebb  and  Flood  Currents  for  Various  Parts  of 
the  Harbor   669 

Table  CXXIV.  Average  Volume  and  Percentage  of  Saturation  of  Dissolved  Oxygen  in  the  Water 
in  the  year  1912.    Summary  of  Tables  CXXI,  CXXII  and  CXXIII   669 

Oxygen  Map  B  following  page  670 

Introduction  to  Tables  CXXV,  CXXVI,  CXXVII,  CXXVIII  and  CXXIX   671 

Table  of  Contents  for  Table  CXXV   672 

Table  CXXV.  Volume  and  Percentage  of  Saturation  of  Dissolved  Oxygen  in  the  Water  in  the 
year  1913   673 

Table  CXXVI.  Average  Volume  and  Percentage  of  Saturation  of  Dissolved  Oxygen  in  the  Water 
in  the  year  1913.    Averages  for  Various  Parts  of  the  Harbor   699 

Table  CXXVII.  Average  Volume  and  Percentage  of  Saturation  of  Dissolved  Oxygen  in  the  Water 
in  the  year  1913.  Averages  of  Samples  Taken  at  Surface,  Mid-Depth  and  Bottom  for  Various 
Parts  of  the  Harbor   700 

Table  CXXVIII.  Average  Volume  and  Percentage  of  Saturation  of  Dissolved  Oxygen  in  the 
Water  in  the  year  1913.  Averages  of  Samples  Taken  on  Ebb  and  Flood  Currents  for  Various 
Parts  of  the  Harbor   702 

Table  CXXIX.  Average  Volume  and  Percentage  of  Saturation  of  Dissolved  Oxygen  in  the 
Water  in  the  year  1913.    Summary  of  Tables  CXXVI,  CXXVII  and  CXXVIII   703 

Introduction  to  Table  CXXX   704 

Table  CXXX.  Average  Volume  and  Percentage  of  Saturation  of  Dissolved  Oxygen  in  the  Water 
in  the  year  1913.    Averages  of  Samples  Taken  in  the  Cross-sections  of  the  Tidal  Channels . .  705 

Oxygen  Maps  C  and  D  following  page  706 

Oxygen  Diagrams: 

Introduction  to  Oxygen  Diagrams   707 

Oxygen  Diagrams.  Variations  During  a  Tidal  Cycle,  in  Dissolved  Oxygen  in  the  Water  through 
Cross-sections  of  Tidal  Channels  in  the  year  1913   708 

Section  IV.    Consumption  of  Dissolved  Oxygen  by  Various  Mixtures  of  Water,  Sewage  and  Sludge  During 

Incubation   722 

Sources  of  Samples   722 

Consumption  of  Dissolved  Oxygen  on  Incubating  Sea  Water   722 

Consumption  of  Dissolved  Oxygen  by  Lower  East  River  Water   723 

Consumption  of  Dissolved  Oxygen  by  Water  from  Various  Points  in  the  Harbor   724 

Dissolved  Oxygen  in  Harbor  Water  in  Cold  and  in  Warm  Weather   727 

Dissolved  Oxygen  on  Ebb  and  Flood  Tides   729 

Dissolved  Oxygen  in  Surface  and  Bottom  Samples   729 

Consumption  of  Oxygen  in  Mixtures  of  Sewage  and  Aerated  Water  During  Incubation   730 

Consumption  of  Dissolved  Oxygen  in  Mixtures  of  Harbor  Water  with  20  per  cent,  of  Raw  and  20  per 

cent,  of  Settled  Sewage   730 

Consumption  of  Dissolved  Oxygen  in  Mixtures  of  Harbor  Water  with  5  per  cent,  of  Raw  and  5  per  cent. 

of  Settled  Sewage   731 

Consumption  in  Mixtures  of  Land  Water  with  Various  Percentages  of  Filtered  Sewage   733 

Consumption  in  Mixtures  of  Sea  Water  with  Various  Percentages  of  Filtered  Sewage   733 

Consumption  in  Mixtures  of  Filtered  Sewage  and  Water  Containing  Various  Initial  Percentages  of  Oxygen  734 

Oxygen  Consumed  by  Sludge   735 

Conclusions   736 

Section  V.    The  Absorption  of  Dissolved  Oxygen  by  Land  Water  and  Sea  Water  and  Mixtures  Thereof. . .  738 

Absorption  by  Land  Water   738 

Absorption  by  Sea  Water   740 

Absorption  by  Mixtures  of  Land  and  Sea  Water   742 

Conclusions   743 

Section  VI.    Chemical  Analyses  of  Harbor  Water   744 

Table  of  Contents  for  Table  CLXIV   745 

Table  CLXIV.    Chemical  Analyses  of  Harbor  Water   746 

Organization  and  Force  Employed   759 

Reports  Issued  by  the  Commission   761 


PART  I. 

Summary  of  the  Work  1906-1914 


■ 


PART  I 

Summary  of  the  Work  1906-1914 

With  the  making  of  this  report  and  in  accordance  with  instructions  from  the 
Legislature,  the  Commission  submits  to  the  Mayor  a  general  plan  of  main  drainage, 
sewage  collection  and  disposal  for  the  whole  city,  and  recommends  that  a  special 
commission  be  created  or  designated  to  build  and  maintain  the  works.  The  plan  is 
sufficiently  definite  to  show  the  nature,  extent  and  approximate  cost  of  the  works. 
Such  detailed  studies  of  design  as  may  be  necessary  before  the  final  estimates  and  con- 
tracts are  prepared  can  appropriately  be  made  by  those  who  are  intrusted  with  the 
construction. 

To  place  the  construction  in  the  hands  of  a  commission  to  be  created  or  designated 
for  the  purpose  is  in  accordance  with  the  precedent  followed  by  the  city  heretofore  in 
connection  with  its  water  supplies  and  subways.  The  Metropolitan  Commission  does 
not  seek  authority  for  carrying  its  recommendations  into  effect. 

The  System  Recommended 

The  system  recommended  consists  largely  of  intercepting  sewers,  running  approx- 
imately parallel  to  the  water  front,  to  collect  the  sewage  from  the  local  sewerage  sys- 
tems to  a  number  of  centrally  situated  disposal  plants  where  sufficient  of  the  impurities 
can  be  removed  to  permit  the  effluent  to  be  discharged  into  the  waters  without  danger 
or  offense.  To  facilitate  the  diffusion  and  assimilation  of  the  sewage  materials  by 
the  water,  it  will  be  desirable  to  place  the  outlets  at  the  bottom  of  the  deep  and 
swiftly-flowing  channels. 

The  system  of  main  drainage  which  the  Commission  recommends  is  presented  for 
adoption  by  the  city  both  as  a  plan  and  policy  for  future  construction  and  should  be 
carried  out  in  successive  stages  and  not  as  one  undertaking.  The  immediate  con- 
struction of  the  whole  scheme  is  not  necessary  from  a  sanitary  standpoint.  Such 
parts  of  the  system  as  are  needed  for  the  immediate  future  should  be  taken  in  hand 
at  once  and  the  remainder  built  as  required.  The  plans  are  sufficiently  flexible  to  per- 
mit of  the  adoption  of  any  discoveries  or  improvements  in  the  art  of  sewage  disposal 
which  may  be  made  in  the  future. 

When  complete,  the  works  will  constitute  a  systematic  and  well  co-ordinated 
scheme  of  main  drainage  for  the  whole  city  which  will  utilize  the  absorptive  capacity 


20  SUMMARY  OP  THE  WORK 

of  the  harbor  waters  to  the  greatest  extent  consistent  with  due  regard  to  the  public 
health  and  welfare. 

Scope  and  Legal  Authority 

The  authority  and  instructions  in  accordance  with  which  the  Commission's  work 
has  been  done  are  to  be  found  in  four  acts  of  the  Legislature  of  the  State  of  New 
York.  Of  these,  Chapter  200  of  the  Laws  of  1910  and  Chapter  332  of  the  Laws  of 
1913  merely  extended  the  life  of  the  Commission.  Chapter  422  of  the  Laws  of  1908 
continued  the  Commission  from  May,  1909,  to  May,  1910,  placed  the  compensation 
of  the  Commissioners  on  a  salary  instead  of  a  per  diem  basis  and  authorized  the  Board 
of  Estimate  and  Apportionment  of  New  York  City  to  provide  the  means  for  carrying 
out  the  legislature's  instructions  in  a  sum  not  to  exceed  $75,000  in  any  one  year. 

Aside  from  the  foregoing,  the  authority  and  instructions  of  the  Commission  are 
contained  in  Chapter  639  of  the  Laws  of  1906.  This  act  required  the  Commission  to 
continue  the  work  of  the  New  York  Bay  Pollution  Commission  which  was  established 
by  Chapter  639  of  the  State  Laws  of  1903,  and  extend  that  work  so  as  to  include  the 
following  duties : 

1.  To  make  further  investigations  into  the  present  and  probable  future 
sanitary  condition  of  the  waters  of  New  York  bay  and  other  bodies  of  water 
within  or  adjacent  to  the  several  boroughs  of  New  York  City  and  neighboring 
districts. 

2.  To  consider  and  investigate  the  most  effective  and  feasible  means  of 
permanently  improving  and  protecting  the  purity  of  the  waters  of  New  York 
bay  and  neighboring  waters,  giving  attention  particularly  to  the  following 
subjects : 

(a)  Whether  it  is  desirable  and  feasible  for  New  York  City  and  the  munici- 
palities in  its  vicinity  to  agree  upon  a  general  plan  or  policy  of  sewerage 
and  sewage  disposal  which  will  protect  the  waters  of  New  York  bay  and  vicin- 
ity against  unnecessary  and  injurious  pollution  by  sewage  and  other  wastes; 

(b)  What  methods  of  collecting  and  disposing  of  the  sewage  and  other 
wastes  which  pollute,  or  may  eventually  pollute,  the  waters  contemplated  in 
this  act  are  most  worthy  of  consideration ; 

(c)  Whether  it  is  desirable  to  establish  a  sewerage  district  in  order  prop- 
erly to  dispose  of  the  wastes,  and  adequately  protect  the  purity  of  the  waters, 
contemplated  in  this  act,  and  if  so,  what  should  be  the  limits  and  boundaries 
of  this  sewerage  district; 


SUMMARY  OF  THE  WORK  21 

(d)  What  would  be  the  best  system  of  administrative  control  for  the  in- 
ception, execution  and  operation  of  a  plan  for  sewerage  and  ultimate  sewage 
disposal  of  a  metropolitan  sewerage  district;  whether  by  the  action  of  already 
existing  departments  and  provisions  of  government,  by  the  establishment  of 
separate  and  distinct  sewerage  districts  and  permanent  commissions  of  each 
state,  by  one  interstate  metropolitan  sewerage  district  and  commission  to  be 
established  by  agreement  between  the  two  States,  this  agreement  if  necessary 
to  be  ratified  by  congress  or  by  other  means. 

3.  To  co-operate  with  any  duly  authorized  body  or  commission  having 
similar  authority  in  the  State  of  New  Jersey  in  the  joint  investigation  and  con- 
sideration of  the  various  subjects  specified  in  this  act. 

4.  To  submit  to  the  Mayor  a  full  and  complete  report  of  the  investigations, 
conclusions  and  recommendations. 

To  facilitate  the  work  intended,  the  Commission  was  given  all  the  powers  of  com- 
mittees of  the  State  Legislature,  authority  to  administer  oaths,  subpoena  witnesses 
and  take  testimony.  Power  was  also  given  to  engage  engineers,  chemists,  bacteri- 
ologists and  other  assistants  and  to  incur  such  other  expenses  as  might  be  necessary. 

Upon  the  termination  of  the  Commission's  work,  its  data  and  other  effects  were 
required  to  be  turned  over  to  the  Board  of  Estimate  and  Apportionment  of  New  York 
City. 

In  a  court  decision  rendered  in  December,  1908,  the  Commission  was  declared  to 
be  a  State  body.  This  judgment  was  rendered  in  a  suit  brought  to  determine  whether 
the  Commission  had  a  right  to  fix  the  salaries  of  its  employees  independently  of  the 
provisions  of  the  New  York  City  Charter. 

Briefly  stated,  the  Commission  was  a  temporary  investigating  and  advisory  board 
appointed  by  the  Mayor  of  New  York  City  in  accordance  with  mandatory  legislation 
by  the  State.  The  Legislature  specified  the  work  to  be  done  and  conferred  broad 
powers  for  the  accomplishment  of  the  desired  results.  The  City  of  New  York  granted 
the  Commission  appropriations  aggregating  $265,000,  this  money  being  voted  by  the 
Board  of  Estimate  and  Apportionment  from  time  to  time  after  fully  investigating  the 
uses  to  which  it  was  to  be  put.  On  three  occasions  the  Commission  was  continued  by 
the  Legislature  at  the  instance  of  the  Mayor  of  New  York,  the  original  period  of 
existence  of  three  years  being  extended  to  ten  years.  After  eight  years,  the  Commis- 
sioners resigned,  stating  that  their  work  had  been  accomplished  and  that  it  was  the 
unanimous  opinion  of  all  who  had  a  thorough  knowledge  of  the  conditions  that  the 
time  had  come  to  provide  for  the  construction  and  maintenance  of  the  necessary 
works. 


22  SUMMARY  OP  THE  WORK 

Work  Reported  to  May,  1910 

The  questions  raised  by  the  Legislature  were  answered  in  a  report  dated  April 
30,  1910.  The  report  stated  that  the  Commission  had  undertaken  to  establish  the 
facts  attending  the  discharge  of  sewage  in  the  metropolitan  district,  to  determine  the 
extent  to  which  the  resulting  pollution  was  injurious  to  the  public  health  and  welfare 
and  to  ascertain  what  it  would  be  necessary  to  do  in  order  to  meet  the  reasonable 
requirements  of  the  present  and  future.  A  study  had  been  made  of  the  capacity  of 
the  waters  for  harmlessly  assimilating  sewage.  The  sewerage  systems  of  New  York 
and  other  cities  within  twenty  miles  of  the  New  York  City  Hall  had  been  examined 
and  estimates  made  of  the  population  and  quantities  of  sewage  discharged  from  the 
houses  and  streets  by  the  human  and  animal  populations.  Careful  estimates  of  the 
future  population  had  been  made  and,  particularly,  its  location  and  density.  Experi- 
mental studies  had  been  conducted  to  determine  the  possibility  of  diffusing  and  dis- 
posing of  sewage  through  the  waters,  of  the  harbor  without  offense  or  danger  to  the 
public  welfare.  Tests  had  been  made  to  determine  the  extent  to  which  public  bathing 
places  and  shellfish  beds  were  polluted  by  sewage.  An  investigation  of  the  tidal 
phenomena  of  the  harbor  had  been  carried  on  in  co-operation  with  the  U.  S.  Coast 
and  Geodetic  Survey.  After  ascertaining  the  essential  details  of  various  trunk  sewer 
projects  which  threatened  to  add  materially  to  the  pollution  of  the  harbor,  the  Com- 
mission had  expressed  an  adverse  opinion  on  the  discharge  of  untreated  sewage  from 
these  trunk  sewers.  An  examination  into  the  legal  jurisdiction  exercised  over  the 
harbor  waters  had  been  undertaken  in  order  to  aid  in  determining  the  best  form  of 
administration  for  a  comprehensive  system  of  sanitary  conservancy. 

At  the  instance  of  the  Commission  and  in  accordance  with  the  legislative  acts 
which  provided  for  its  creation,  communications  were  twice  sent  by  the  Secretary  of 
State  of  New  York  to  the  Governor  of  New  Jersey  inviting  New  Jersey  to  co-operate 
in  the  work  which  the  Commission  was  performing.  These  invitations  were  without 
result.    The  report  of  1910  was  a  volume  of  550  quarto  pages. 

The  recommendations  which  the  Commission  made  were  such  as  had  been  found 
successful  in  other  populous  centers  in  Europe  and  America.  They  were  to  the  effect 
that  the  metropolitan  territory  should  be  divided  into  sections  with  boundaries  to  be 
determined  partly  by  the  quantities  of  sewage  produced,  partly  by  the  facilities  which 
existed  in  the  several  localities  for  disposing  of  the  wastes  in  a  sanitary  manner  and 
partly  by  considerations  of  cost. 

No  single  system  of  conduits  to  collect  the  sewage  of  the  whole  district  and  carry 
it  to  one  point  for  disposal  was  considered  practical.  To  a  considerable  extent  puri- 
fication works  embodying  the  principles  of  sedimentation,  screening  and  filtration 


SUMMARY  OP  THE  WORK  23 

should  be  employed.  There  should  be  prepared  an  outline  plan  to  which  all  future 
sewerage  works  should  conform  so  far  as  that  work  related  to  the  disposal  of  sewage 
and  there  should  be  plans  drawn  in  some  detail  for  the  disposal  of  the  sewage  of  indi- 
vidual districts.  This  program  involved  for  the  immediate  future  no  expenditure  or 
commitment  of  the  City  or  State  beyond  the  expenses  of  the  commission  to  prepare 
the  plans. 

A  large  part  of  the  sewage  discharged  into  the  Harlem  river  and  neighboring 
waters  should  be  intercepted  and  taken  elsewhere  for  disposal  in  order  to  do  away 
with  the  existing  nuisances.  Special  detailed  studies  should  be  made  for  improved 
sewerage  and  sewage  disposal  for  the  portions  of  the  Boroughs  of  Queens  and  Brooklyn 
bordering  on  Jamaica  bay  and  the  East  river  at  the  entrance  of  Long  Island  Sound  with 
reference  to  plans  for  the  interception  of  sewage  and  a  determination  of  the  kind  and 
degree  of  the  purification  required. 

Plans  should  be  prepared  as  soon  as  practicable  for  the  reconstruction  of  the 
sewers  of  Manhattan  on  the  separate  plan.  The  new  plans  should  preserve  for  use 
the  existing  sewers  to  as  great  an  extent  as  possible. 

With  respect  to  projects  for  large  trunk  sewers  to  discharge  the  sewage  of  more 
or  less  inland  communities  into  New  York  harbor,  an  adequate  degree  of  purification 
should  be  insisted  upon  under  a  form  of  agreement  which  could  be  legally  enforced. 
The  suit  of  the  State  of  New  York  against  the  Passaic  Valley  Sewerage  Commissioners 
and  the  State  of  New  Jersey  should  be  pressed,  to  the  end  that  proper  provision 
might  be  made  to  protect  the  public  welfare  against  the  pollution  which  the  commis- 
sion considered  likely  to  result  in  spite  of  an  agreement  entered  into  in  1910  between 
the  United  States  Government  and  the  Passaic  Valley  Sewerage  Commissioners  as  to 
purification. 

Great  care  should  be  exercised  in  the  location  of  public  bathing  establishments 
to  avoid  unsafe  localities  and  the  free  floating  bathing  establishments  around  the 
water  front  should  be  gradually  abolished,  properly  planned  bathing  places  supplied 
with  pure  water  being  substituted  therefore. 

The  methods  of  designing  and  constructing  sewers  in  the  metropolitan  district 
should  be  made  standard,  where  feasible.  Closer  co-operation  should  be  effected  be- 
tween the  departments  and  bureaus  concerned  with  the  construction  and  maintenance 
of  the  sewers  of  New  York.  Legal  steps  should  be  taken  to  give  the  inspectors  of  the 
Bureaus  of  Sewers  of  New  York  the  right  to  enter  upon  property  for  the  purpose  of 
inspecting  the  sewer  connections  of  houses  in  order  to  protect  the  sewers  against  acids, 
hot  liquids,  steam  and  other  injurious  trade  wastes. 

In  conclusion,  the  Commission  stated  that  it  had  formulated  a  general  plan  or 


24  SUMMARY  OF  THE  WORK 

policy  by  which  the  sanitary  condition  of  the  harbor  could  be  permanently  protected 
and  improved.  It  recommended  that  the  duty  of  carrying  out  this  policy  be  placed 
in  the  hands  of  a  special  board  of  Commissioners.  The  first  duty  of  the  Commission 
proposed  would  be  to  utilize  the  information  which  had  been  collected  and  plan  the 
necessary  work. 

Work  Reported  prom  May,  1910,  to  August,  1912. 

Upon  receipt  of  the  Commission's  report  of  1910,  the  Mayor  requested  the  Com- 
missioners to  continue  to  serve  in  order  to  extend  the  investigations  and  prepare  plans 
and  the  legislation  necessary  to  continue  the  Commission  for  three  years  was  passed. 
Delays  incurred  owing  to  the  performance  of  work  not  anticipated  and  it  being  found 
that  the  Commission  could  not  finish  its  final  report  before  May,  1913,  the  Mayor  again 
had  the  life  of  the  Commission  extended  by  the  Legislature. 

The  work  done  from  1910  to  1914  was  chiefly  confined  to  the  City  of  New  York  and 
that  part  of  the  harbor  which  lay  wholly  or  in  part  within  the  New  York  State  bound- 
ary. The  Commission  proceeded  to  lay  out  a  general  plan  of  main  drainage  and 
sewage  disposal  for  New  York  City  in  accordance  with  the  information  and  opinions 
derived  from  the  preceding  investigations. 

Before  the  completion  of  a  definite  project  of  main  drainage  and  sewage  disposal 
and  before  any  public  announcement  of  the  plan,  the  engineer  in  charge  of  the  sewers 
of  the  borough  in  which  the  proposed  works  would  be  located  was  invited  to  criticise 
the  plans.  This  invitation  was  always  accepted  and,  in  some  cases,  material  modi- 
fications in  the  original  plans  were  made  in  order  to  meet  the  suggestions  of  the  local 
authorities.  Works,  substantially  as  recommended  in  the  present  report,  were  an- 
nounced for  the  City  of  New  York,  this  announcement  being  made  in  the  form  of 
printed  preliminary  reports  with  tables  of  cost  and  other  data  and  accompanied  by 
lithograph  maps  and  profiles  showing  the  approximate  location,  size,  elevation  and 
capacity  of  the  collectors  and  interceptors,  the  location  of  the  disposal  works  and  out- 
falls and  other  material. 

In  August,  1912,  the  Commission  published  a  report  in  the  form  of  a  bound  volume 
of  about  450  pages  which  contained  a  description  of  the  present  sanitary  condition  of 
the  harbor  and  the  "degree  of  cleanness"  necessary  and  sufficient  for  the  water  and  the 
results  of  analytical  examinations  of  the  harbor  waters  and  deposits  from  the  harbor 
bottom.  In  describing  the  sanitary  condition  of  the  harbor,  the  volume  and  circula- 
tion of  the  water  was  dealt  with  and  an  account  given  of  the  composition  and  volume 
of  the  sewage  which  was  discharged  into  the  harbor,  the  appearance  of  the  water,  the 
phenomena  of  digestion  and  mechanical  transportation  of  the  sewage  particles,  the 


SUMMARY  OP  THE  WORK  25 

state  of  the  water  as  shown  by  the  dissolved  oxygen  and  the  intensity  of  pollution 
as  indicated  by  bacterial  and  microscopical  analyses. 

The  study  of  the  degree  of  cleanness  necessary  and  sufficient  for  the  water  was 
taken  up  largely  for  the  Board  of  Estimate  and  Apportionment  which  had  been  ad- 
vised by  consulting  experts,  after  an  investigation,  that  the  city  should  seek  to  main- 
tain 70  per  cent,  of  the  saturation  value  of  dissolved  oxygen  in  the  water  and  the 
Board  desired  to  have  a  special  commission  created  to  make  a  further  investigation 
and  report  on  this  subject.  The  Metropolitan  Sewerage  Commission's  offer  to  engage 
experts  and  make  a  report  upon  the  proper  degree  of  cleanness  was  accepted  and  the 
1912  report  contains  the  Commission's  opinion,  a  summary  of  the  opinions  of  the 
experts  and  the  reports  in  full  of  the  eight  experts  who  were  called  upon. 

The  analytical  data  which  were  published  in  the  1912  report  were  shown  in  the 
form  of  tables,  maps  and  diagrams,  all  carefully  co-ordinated  to  facilitate  examination. 

The  Pinal  Report 

Among  the  reports  not  otherwise  described  here  were  Preliminary  Reports  VIII 
to  XVII,  printed  and  distributed  between  November,  1913,  and  April,  1914.  These 
reports  with  additional  matter  are  brought  together  in  this  final  report  of  the 
Commission. 

A  large  amount  of  work  has  been  done  by  the  Commission  which  has  not  and 
cannot  well  be  reported  upon  without  exceeding  reasonable  limits  of  expense.  Some 
of  this  work  has  been  done  in  the  chemical  and  bacteriological  laboratories  which  the 
Commission  has  continuously  maintained  since  1908.  Other  investigations  have  cov- 
ered special  engineering  topics,  such  as  dredging  and  the  preparation  of  alternative 
plans  for  the  collection  and  disposal  of  the  sewage.  Practically  all  of  these  studies 
have  been  recorded  in  the  form  of  reports  and  are  among  the  extensive,  systematically 
arranged  records  in  the  Commission's  office. 

Experts  Consulted 

Assisting  the  Commission  in  the  conduct  of  its  investigations  and  in  the  prepara- 
tion of  its  projects  have  been  a  large  number  of  engineers,  chemists  and  bacteriolo- 
gists. Throughout  its  work  the  Commission  has  followed  the  policy  of  inviting  the 
best  qualified  experts  obtainable  to  contribute  criticism,  both  constructive  and 
destructive,  the  intention  being  to  make  the  investigations  represent  the  broadest,  most 
valuable  and  authoritative  treatment  of  New  York's  sewage  problem  which  could  be 
obtained. 


26  SUMMARY  OF  THE  WORK 

Following  is  a  list  of  the  professional  consultants  engaged  by  the  Commission  at 
various  times  between  October  7,  1908,  and  January  14,  1914 : 

W.  E.  Adeney,  Sc.D.,  F.I.C.,  Consulting  Chemist,  Dublin,  Ireland. 

Charles  V.  Chapin,  M.D.,  Sc.D.,  Superintendent  of  Health,  Providence,  R.  I. 

George  E.  Datesman,  C.E.,  M.  Am.  Soc.  C.E.,  Bureau  of  Surveys,  Philadelphia,  Pa. 

Harrison  P.  Eddy,  B.S.,  M.  Am.  Soc.  C.E.,  Consulting  Engineer,  Boston,  Mass. 

Desmond  Fitzgerald,  Past  President,  M.  Am.  Soc.  C.E.,  Consulting  Engineer, 
Brookline,  Mass. 

Gilbert  J.  Fowler,  Sc.D.,  F.I.C.,  Superintendent,  Sewage  Disposal  Works,  Man- 
chester, England. 

George  W.  Fuller,  B.S.,  M.  Am.  Soc.  C.E.,  Consulting  Engineer,  New  York  City. 

Augustus  H.  Gill,  Ph.D.,  Professor  of  Gas  Analysis,  Massachusetts  Institute  of 
Technology,  Boston,  Mass. 

X.  H.  Goodnough,  C.E.,  M.  Am.  Soc.  C.E.,  Chief  Engineer  of  the  Massachusetts 
State  Board  of  Health,  Boston,  Mass. 

Rudolph  Hering,  Sc.D.,  M.  Am.  Soc.  C.E.,  Consulting  Engineer,  New  York  City. 

Karl  Imhoff,  Dr.  Ing.,  Chief  Engineer,  Sewer  Department,  Emschergenossenschaft, 
Essen,  Germany. 

Floyd  J.  Metzger,  Ph.D.,  Professor  of  Analytical  Chemistry,  Columbia  University, 
New  York  City. 

William  P.  Mason,  C.E.,  M.D.,  M.  Am.  Soc.  C.E.,  Professor  of  Chemistry,  Rens- 
selaer Polytechnic  Institute,  Troy,  N.  Y. 

Samuel  Rideal,  Sc.D.,  F.I.C.,  Consulting  Chemist,  Westminster,  London,  England. 

William  T.  Sedgwick,  Ph.D.,  Sc.D.,  Professor  of  Biology  and  Sanitary  Science, 
Massachusetts  Institute  of  Technology,  Boston,  Mass. 

F.  Herbert  Snow,  M.  Am.  Soc.  C.E.,  Chief  Engineer,  State  Department  of  Health, 
Harrisburg,  Pa. 

J.  H.  Stebbius,  Ph.D.,  Microscopist  and  Chemist,  New  York  City. 

C.-E.  A.  Winslow,  M.S.,  Curator,  Department  of  Health,  American  Museum  of 
Natural  History,  New  York  City. 

John  D.  Watson,  M.  Inst.  C.E.,  Engiueer,  Birmingham,  Tame  and  Rae  District 
Drainage  Board,  Birmingham,  England. 

W.  F.  Willcox,  Ph.D.,  Professor  of  Statistics,  Cornell  University,  Ithaca,  N.  Y. 

In  arriving  at  a  conclusion  upon  the  subject  of  administration,  a  recommendation 
as  to  which  w;is  one  of  its  specified  duties,  the  Commission  had  the  benefit  of  the  views 
of  a  number  of  citizens  who,  from  official  position  or  other  practical  experience,  are 


SUMMARY  OF  THE  WORK  27 

particularly  well  qualified  to  advise.  The  number  included  Ex-Mayors  Seth  Low  and 
George  B.  McClellan,  also  Messrs.  Lawson  N.  Purdy,  Robert  W.  DeForest,  Henry  R. 
Towne,  E.  H.  Outerbridge,  George  L.  Rives  and  Charles  Strauss. 

Need  of  Immediate  Action. 

As  to  the  urgency  of  providing  a  system  of  main  drainage  and  sanitary  sewage 
disposal,  the  Commission  and  its  advisers  strongly  recommend  that  steps  at  once  be 
taken  to  correct  the  evils  which  exist.  Even  if  corrective  measures  are  begun  immedi- 
ately, it  will  necessarily  be  some  years  before  the  works  can  be  completed  and  their 
benefit  can  be  realized. 

At  the  present  time  the  crude  sewage  of  a  population  of  over  6,000,000  persons  is 
discharged  through  several  hundred  outlets  into  the  harbor  without  purification,  regula- 
tion or  control  of  any  kind.  The  discharges,  all  of  which  take  place  at  the  shore  line  or 
beneath  the  docks  and  piers,  discolor  the  water,  pollute  the  shores,  produce  offensive 
deposits  and  cause  solid  matters,  plainly  recognizable  as  of  sewage  origin,  to  float  about 
in  plain  sight.  Bathing  and  the  taking  of  shellfish  for  food  are  no  longer  safe  north  of 
the  Narrows. 

The  pollution,  objectionable  as  it  is  at  the  present  time,  is  rapidly  increasing. 
Within  the  next  thirty  years  the  population  will  be  about  double  what  it  is  to-day  and 
the  quantity  of  sewage  will  increase  in  proportion. 

The  pollution  is  most  objectionable  in  summer  when  it  is  desirable  that  the  water 
should  be  cleanest  ;  it  is  most  intense  in  those  sections  where  the  density  of  popula- 
tion and  the  congestion  of  water  traffic  are  greatest. 

The  Commissioners  feel  confident  that  their  recommendation  to  place  the  dis- 
posal of  New  York  sewage  under  a  special  commission  will  prove  to  be  a  measure  of 
economy,  since  this  concentration  of  responsibility  for  the  sanitary  disposal  of  the  sew- 
age will  insure  an  orderly  and  well  co-ordinated  development  of  the  City's  main  drain- 
age works  and  prevent  either  the  piecemeal  construction  of  works  intended  to  improve 
intolerable  local  conditions  or  unnecessarily  comprehensive  and  expensive  main  drain- 
age schemes. 

The  members  of  the  Commission  feel  that  they  cannot  state  the  need  of  improve- 
ment too  strongly.  The  public  has  been  made  aware  of  the  situation  through  the 
numerous  reports  which  the  Commission  has  issued  from  time  to  time.  Among  great 
cities,  New  York  is  practically  alone  in  not  possessing  either  a  system  of  main  drain- 
age and  sewage  disposal  or  a  plan  and  policy  for  the  sanitary  conservation  of  its  water 
highways. 


PART  II. 

Plans  for  the  Protection  of  the  Harbor 


PART  II 


Plans  for  the  Protection  of  the  Harbor 

CHAPTER  I 
PRELIMINARY  CONSIDERATIONS 

In  a  report  issued  by  this  Commission  April  30,  1910,  it  was  recommended  that  a 
sewerage  district  and  commission  be  created  for  that  part  of  the  States  of  New  York 
and  New  Jersey  whose  natural  drainage  was  directly  tributary  to  New  York  harbor. 
The  studies  which  had  been  made  indicated  that  all  the  territory  within  about  20 
miles  of  the  New  York  City  Hall,  embracing  about  TOO  square  miles  in  the  two  States, 
should  be  included.  This  entire  district  had  been  under  investigation  and  a  boundary 
for  the  territory  had  been  provisionally  established  in  accordance  with  the  natural 
water  sheds  and  with  regard  to  the  distribution  of  population.  The  district  extended 
to  the  village  of  White  Plains,  N.  Y.,  to  the  north,  to  the  mouth  of  the  Raritan  river, 
N.  J.,  on  the  south  and  from  the  easterly  limits  of  New  York  City  far  enough  west  to 
include  the  municipalities  of  Paterson,  Summit  and  Perth  Amboy,  N.  J.  About  90 
municipalities  lay  within  this  territory. 

Dividing  the  district  about  equally  in  a  general  north  and  south  direction  is  a 
line  separating  New  York  from  New  Jersey.  Inasmuch  as  the  interstate  ooundary 
passes  for  some  miles  through  the  center  of  the  harbor,  no  plan  for  protecting  these 
waters  can  be  carried  out  with  satisfactory  effect  without  some  form  of  cooperation. 

Cooperation  between  the  two  States  in  devising  a  comprehensive  plan  or  policy 
for  protecting  the  harbor  against  excessive  pollution  has  been  sought  by  New  York 
without  effect.  The  legislative  bill  providing  for  the  creation  of  the  Metropolitan 
Sewerage  Commission  of  New  York  authorized  and  directed  this  body  to  act  in  concert 
with  a  similar  board  to  be  created  by  New  Jersey.  To  this  end  an  invitation  was 
twice  extended  to  the  Governor  of  New  Jersey  by  the  Secretary  of  State  of  New 
York  before  the  year  1910.  In  the  absence  of  cooperation,  investigations  of  the  con- 
ditions of  sewerage  and  sewage  disposal  in  the  entire  metropolitan  district  were 
carried  on  by  the  New  York  Commission  for  four  years.  The  results  of  these  studies 
have  been  made  freely  available  to  the  people  of  the  two  States  by  the  publication  of 
the  report  of  the  Metropolitan  Sewerage  Commission  of  New  York  in  April,  1910. 

For  the  three  years  following  the  publication  of  its  report  of  1910,  this  Commis- 
sion confined  its  attention  to  that  part  of  the  metropolitan  sewerage  district  which  lay 
within  the  State  of  New  York,  the  reason  for  restricting  its  attention  to  this  part  of 


32 


PLANS  FOR  THE  PROTECTION  OF  THE  HARBOR 


the  district  having  arisen  mainly  from  a  change  in  the  nature  of  this  Commission's 
work.  Occupied  before  1910  with  the  collection  of  data  relating  to  the  conditions  of 
sewerage  and  sewage  disposal  as  existing  up  to  this  time,  this  Commission's  attention 
was  subsequently  given  to  the  work  of  laying  down  the  essentials  of  an  improved  plan 
of  main  drainage  and  sewage  disposal  for  New  York  City. 

In  laying  out  an  improved  system  for  the  disposal  of  the  sewage  of  New  York 
City,  this  Commission  has  received  assistance  from  the  sewer  bureaus  of  New  York 
and  from  various  departments  and  officials  of  the  metropolis  whose  aid  has  been 
requested.  The  plans  have  been  largely  based  upon  information  thus  obtained  and  the 
various  projects  have  received  the  benefit  of  criticism  from  the  city  officials  charged 
with  the  duty  of  maintaining  the  local  drainage  systems  in  the  various  parts  of  the 
city.  As  soon  as  plans  for  any  part  of  the  territory  have  been  brought  to  a  reason- 
able state  of  maturity,  they  have  been  issued  by  this  Commission  in  the  form  of  a  pre- 
liminary report  in  order  that  the  public  might  be  informed  as  early  as  possible  and 
such  modifications  might  be  made  in  the  plans  for  local  drainage  as  would  be  neces- 
sary in  order  to  conform  with  the  larger  projects  of  main  drainage. 

The  total  number  of  preliminary  reports  leading  up  to  or  describing  works  has 
been  six.  The  projects  announced  in  the  preliminary  reports  are  brought  together  in 
the  following  pages  with  such  modifications  as  further  study  and  criticism  have  seemed 
to  make  desirable. 

Of  the  six  preliminary  reports,  the  first  was  concerned  with  the  possibility  of  col- 
lecting all  the  sewage  of  New  York  City  to  a  central  point  for  disposal. 

The  second  preliminary  report  described  the  four  principal  drainage  divisions  in 
that  part  of  the  metropolitan  sewerage  district  which  lies  in  New  York  State. 

The  third  preliminary  report  described  a  study  of  the  collection  and  disposal  of 
the  sewage  of  the  Jamaica  Bay  Division. 

The  fourth  preliminary  report  was  on  the  collection  and  disposal  of  the  sewage 
of  the  Upper  East  River  and  Harlem  Division. 

The  fifth  preliminary  report  dealt  with  the  collection  and  disposal  of  the  sewage 
of  the  Richmond  Division. 

The  sixth  and  final  preliminary  report  describing  works  recommended  a  plan  for 
the  collection  and  disposal  of  the  sewage  of  the  Lower  East  River,  Hudson  and  Bay 
Division. 

THE  POSSIBILITY  OF  COLLECTING  THE  SEWAGE  TO  A  CENTRAL  POINT 

FOR  DISPOSAL. 

The  benefits  which  would  accrue  from  collecting  all  the  sewage  of  New  York  City 
into  one  complete  system  of  main  drainage  and  pumping  it  out  to  sea  are  so  apparent, 
and  this  plan  has  been  so  frequently  suggested  by  engineers  and  others  who  recog- 


PRELIMINARY  CONSIDERATIONS 


33 


nize  the  need  of  stopping  the  pollution  of  the  harbor,  that  this  Commission  has  given 
serious  attention  to  the  practicability  of  the  project.  There  are  many  ways  in  which 
this  plan  could  be  carried  out  and  the  four  most  promising  forms  of  the  general 
project  have  been  considered.  It  may  be  said  at  the  outset  that  it  is  within  the  range 
of  engineering  ability  to  carry  out  any  of  them,  but  this  Commission  considers  that  the 
benefits  which  would  be  secured  would  not  be  sufficient  to  justify  their  cost.  Other 
and  more  economical  ways  exist  for  sanitating  the  harbor. 

The  point  most  suitable  for  the  outlet  of  the  sewage  would  depend  upon  the  quan- 
tity of  sewage  to  be  disposed  of  and  the  uses  to  which  the  neighboring  shores  of  the 
sea  might  be  put.  The  larger  the  quantity  of  sewage,  the  farther  the  outlet  should  be 
from  land.  The  farther  the  outlet  is  located  from  the  shore,  the  more  costly  the  un- 
dertaking would  become.  It  would  be  necessary  to  carry  the  outlet  a  long  distance 
from  the  shores  if  a  large  volume  of  sewage  was  to  be  discharged  in  crude  condition, 
since  the  coast  line  within  100  miles  of  New  York  in  either  direction  is  composed 
exclusively  of  sandy  beaches  which  are  the  resort  of  large  numbers  of  persons  during 
the  summer  months.  Under  any  circumstances  it  would  not  be  feasible  to  carry  the 
outfall  of  a  sea-going  tunnel  more  than  about  three  miles  from  the  land  because  of 
the  increased  depth  of  the  water.  Other  conditions  which  would  affect  the  location  of 
the  outfall  would  be  the  condition  of  the  sewage  with  respect  to  the  solid  matter  con- 
tained, the  state  of  the  sewage  with  respect  to  putrefaction,  the  force  and  direction  of 
the  tidal  currents  with  regard  to  the  shores  and  the  mouth  of  the  harbor,  and  the  uni- 
formity and  intermittency  of  discharge. 

The  volume  of  sewage  which  would  have  to  be  disposed  of  in  case  all  the  dry- 
weather  flow  were  to  be  discharged  at  sea  would  be  very  great.  Careful  estimates  of 
population  and  quantities  of  sewage  which  will  be  produced  in  the  year  1940  indi- 
cate that  there  will  be  1,330,000,000  gallons  of  sewage  per  twenty-four  hours.  Table 
I  shows  the  estimated  population  of  New  York  City  for  1940 ;  the  present  population 
is  as  enumerated  by  the  United  States  Census  of  1910. 


TABLE  I 

Estimated  Volume  of  Sewage  Flow  in  New  York  City  in  1940.    See  Report  of  the 
Metropolitan  Sewerage  Commission,  Dated  April  30,  1910 


BOROUGH. 

Estimated  Population 
in  1940. 

Estimated  Volume  of 
Sewage  Flow  in  1940. 

Corresponding  Volume  of 
Sewage  Flow  in  Gals,  per 

See  Report  of  1910, 

See  Report  of  1910, 

Capita  per  24  Hours. 

page  144. 

page  146.  Mgd.* 

Manhattan  

3,600,000 

583 

162 

The  Bronx  

1,200,000 

159 

132 

Brooklyn  

3,200,000 

426 

133 

Queens  

870,000 

138 

159 

Richmond  

130,000 

24 

185 

Total  

9,000,000 

1,330 

148 

'Million  gallons  per  day  of  24  hours. 


34  FLANS  FOR  THE  PROTECTION  OF  THE  HARBOR 

The  estimates  of  population  and  sewage  flow  contained  in  Table  I  are  revised 
from  the  figures  which  originally  appeared  in  the  report  of  this  Commission,  dated 
April  30,  1910.  When  that  report  was  being  prepared,  the  United  States  census  for 
1910  had  not  been  completed.  Estimates  made  by  this  Commission  indicated  that  the 
population  was  about  4,600,000,  whereas  enumeration  by  the  Census  Bureau  showed 
it  to  be  slightly  greater,  or  4,766,883.  In  view  of  the  fact  that  the  city  was  growing 
more  rapidly  than  had  been  assumed  by  the  Commission,  the  estimates  for  the  popula- 
tion of  New  York  for  the  year  1940  had  to  be  corrected.  In  place  of  a  population  of 
8,660,100  which  had  been  forecasted  in  the  report  of  April,  1910,  the  revised  forecast 
became,  roundly,  9,000,000. 

The  first  estimates  of  the  sewage  flow  for  1940  were  1,580,000,000  gallons,  and 
this  figure  was  published  in  the  report  of  April,  1910.  With  more  definite  knowledge 
of  the  population  in  1910,  and  with  better  information  concerning  the  probable  total 
water  consumption  as  studied  by  the  Board  of  Water  Supply,  this  Commission's  fig- 
ures for  sewage  flow  in  1940  were  revised  to  1,330,000,000  gallons  per  twenty-four 
hours.  How  great  is  this  volume  of  sewage  can  be  understood  from  the  fact  that  it 
would  equal  a  stream  10  feet  deep  and  46.7  feet  wide  flowing  at  the  rate  of  3  miles  an 
hour. 

The  state  of  the  sewage  with  reference  to  putrefaction  would  probably  neither 
favor  nor  hinder  its  prompt  disappearance.  The  largest  solids  would  be  removed  from 
the  sewage  by  screens  for  the  protection  of  the  pumps  which  would  be  required  to  force 
the  sewage  to  the  outlet,  and  much  solid  matter  would  be  broken  up  by  the  passage 
of  the  sewage  through  the  sewers,  so  that  tlie  matters  left  in  suspension  would  consist 
of  very  finely  divided  particles  and  material  in  the  colloid  state.  The  sewers  would 
be  so  long  and,  consequently,  the  time  taken  by  the  sewage  to  reach  the  outlet  would 
be  so  great,  that  the  sewage  would  be  in  a  state  of  decomposition  by  the  time  it 
reached  the  outlet  and  would,  therefore,  be  much  more  offensive  than  fresh  sewage. 
In  consequence  of  this  fact  the  water  in  the  vicinity  of  the  outlet  would  be  more 
offensively  polluted  than  it  would  be  were  the  sewage  to  be  discharged  in  fresh  con- 
dition. The  oxygen  would  almost  certainly  be  entirely  gone  from  solution  in  the 
sewage  and  there  would  be  an  immediate  and  heavy  demand  upon  the  dissolved  oxygen 
in  the  sea  water. 

Just  how  far  the  outlet  would  be  from  shore  would  not  be  susceptible  of  exact 
determination.  From  six  to  ten  miles  seems  not  too  great  a  distance  in  view  of  the 
circumstances  and  yet  it  would  be  difficult,  if  not  impracticable,  to  build  the  outfall  at 
such  a  distant  point  by  any  methods  of  engineering  construction  which  have  thus  far 
been  anywhere  employed. 


PRELIMINARY  CONSIDERATIONS 


35 


Continuous  Discharge  at  Sea 

Experience  shows  that  the  sewage  would  mingle  slowly  with  the  sea  water.  It 
would  in  all  probability  rise  in  a  column  from  the  outlet  at  the  bottom  and  flow  to 
the  top,  there  to  spread  out  and  move  away  under  the  influence  of  the  tidal  currents, 
its  destination  as  sewage  being  determined  partly  by  the  tidal  movements,  partly  by 
the  force  and  direction  of  the  wind  and  partly  by  the  intermixing  action  of  the  waves. 

Studies  made  by  this  Commission  indicated  that  the  currents  of  the  ocean  mid- 
way between  New  York  and  New  Jersey  and  about  15  miles  from  shore  sometimes 
traveled  at  a  rate  of  2  miles  per  hour  under  normal  conditions  of  wind  and  tide.  When 
garbage  was  dumped  at  sea  near  this  point  in  the  year  1906  there  was  a  distinct  foul- 
ing of  the  shore  lines  over  a  distance  of  50  miles  from  New  York  along  Long  Island, 
and  for  70  miles  along  the  shore  of  New  Jersey.  Wind  undoubtedly  had  an  effect 
upon  this  floating  refuse,  but  wind  would  also  have  an  effect  upon  the  movement  of 
sewage.  Wind  moves  the  whole  surface  of  the  water  upon  which  it  blows,  as  has 
been  observed  by  this  Commission  in  studying  the  behavior  of  sewage  in  Upper  New 
York  bay. 

An  examination  of  the  depths  of  water  along  the  New  York  and  New  Jersey 
coast  lines,  as  recorded  upon  the  official  charts  of  the  United  States  Coast  and  Geo- 
detic Survey,  shows  that  there  is  no  point  available  at  a  distance  of  10  miles  from 
shore  to  which  a  sea-going  tunnel  could  well  be  built.  The  bottom  is,  for  the  most 
part,  sandy,  so  that  the  tunnel  would  have  to  be  built  with  compressed  air.  The  depths 
required  would  exceed  120  feet,  which  is  about  the  limit  at  which  it  is  practicable  for 
men  to  exist.  Unless  the  outfall  was  located  at  an  island,  the  tunnel  would  have  to  be 
built  entirely  from  shore,  no  shafts  being  possible  between  the  land  and  the  point  of 
outfall.  This  would  make  the  construction  of  the  tunnel  a  slow  and  costly  under- 
taking. It  is  obvious  that  there  would  be  serious  difficulty  in  the  construction  of 
any  long  tunnel  to  sea.  It  is  not  clear  how  the  outlet  should  be  constructed  in  order 
to  resist  the  destructive  force  of  the  great  Atlantic  storms.  Storms  of  great  violence 
occur  throughout  the  winter  season  in  this  region  and  any  structure  which  rose  con- 
siderably above  the  bottom  would  have  to  be  built  in  a  massive  way  if  it  was  to  be 
permanent.  Such  structures  as  the  intake  cribs  built  for  the  supply  of  water  to  the 
cities  on  the  Great  Lakes  could  scarcely  be  constructed  or  maintained  in  the  At- 
lantic, where  the  storms  are  very  violent,  and  where  there  is  usually  a  pronounced 
ground  swell  in  calm  weather.  If  the  outlet  were  built  merely  as  an  opening  through 
the  bottom  of  the  sea,  it  would  appear  to  be  necessary  to  protect  it  in  some  manner 
against  the  shifting  movement  of  sand  which  is  believed  to  move  in  great  quantities 
along  the  bottom  of  the  New  Jersey  and  Long  Island  shores.  Such  an  outlet  would 
be  difficult  or  impossible  to  examine  or  repair. 


36  PLANS  FOR  THE  PROTECTION  OF  THE  HARBOR 

Discharge  at  Sea  on  Outgoing  Tidal  Currents 

The  length  of  the  sea-going  tunnel  could  be  greatly  shortened  if  the  sewage  could 
be  stored  temporarily  on  shore  and  discharged  only  on  out-going  tidal  currents.  In 
this  case  the  full  benefit  of  the  transporting  power  of  the  water  could  be  utilized  to 
carry  the  sewage  matters  as  far  away  from  the  land  as  possible.  Under  these  circum- 
stances it  would  seem  reasonable  to  locate  the  outlet  within  about  5  miles  from  shore. 
A  point  from  which  it  would  be  suitable  to  build  the  tunnel  would  be  in  the  vicinity 
of  Rockaway  Point,  and  in  this  location  storage  basins  should  be  situated  to  collect 
the  sewage  and  hold  it  until  outgoing  currents  occurred  to  carry  it  away.  Because 
of  the  necessity  for  discharging  only  at  certain  hours,  the  tunnels  would  have  to  be 
larger  or  more  numerous  than  would  be  required  if  the  discharge  took  place 
continuously. 

Assuming  that  the  quantity  of  sewage  to  be  disposed  of  was  1,330,000,000  gallons 
per  day,  and  that  it  would  be  discharged  in  two  periods  of  four  hours  each,  the 
storage  basins  and  pumping  station  which  would  be  required  would  have  to  cover  an 
area  of  about  125  acres.  The  depth  of  the  storage  basins  would  be  25  feet.  The  tun- 
nels would  be  four  in  number  and  18  feet  in  diameter  each.  The  tunnels  would  run 
parallel  to  one  another  until  near  their  outer  ends,  where  they  would  separate  to  some 
extent  before  discharging. 

To  collect  the  sewage  to  the  vicinity  of  Rockaway  Point,  there  would  be  need  of 
a  system  of  collecting  and  intercepting  sewers  running  to  all  parts  of  the  city.  Staten 
Island  would  be  connected  by  a  tunnel  beneath  the  Upper  bay.  Manhattan  would  be 
provided  with  intercepting  sewers  running  around  the  water  front.  The  sewage  would 
pass  under  the  East  river  to  mains  which  would  flow  to  storage  reservoirs.  The  sew- 
age of  Brooklyn  would  be  collected  by  interceptors  and  one  trunk  line  would  run  to 
the  Bronx  and  another  to  a  central  point  for  the  sewage  of  Northern  Queens. 

To  a  large  extent  the  present  local  sewerage  systems  which  receive  the  sewage 
directly  from  the  houses  would  be  utilized,  but  the  main  drainage  system  would  con- 
sist, for  the  most  part,  of  conduits  of  large  magnitude,  some  of  them  approaching  the 
dimensions  of  rapid  transit  subways,  the  principal  main  sewers  being  five  in  number. 

Various  pumping  stations  would  be  required  at  one  or  more  points  on  each  of  the 
five  main  sewers  or  their  branches  and  a  general  pumping  station  would  be  necessary 
at  Rockaway  Inlet  to  pump  the  sewage  to  the  outlet  at  sea.  In  the  estimates  of  cost, 
it  has  been  assumed  that  the  maximum  capacity  of  pumps  in  each  station  would  be 
50  per  cent,  in  excess  of  what  may  be  termed  the  average  capacity  and,  in  addition  to 
this,  a  storage  reserve  capacity  has  been  assumed  in  each  case. 


PRELIMINARY  CONSIDERATIONS  37 

It  has  been  assumed  that  the  sewage  would  be  stored  during  a  period  of  eight 
hours  when  the  tidal  conditions  were  unfavorable  to  a  discharge,  and  that  the  vol- 
ume so  stored  would  be  sent  to  sea  during  the  subsequent  four  hours,  together  with 
the  sewage  which  reached  the  central  pumping  station  during  this  latter  period.  It 
has  been  assumed  that  50  per  cent,  of  the  average  daily  flow  might  reach  the  central 
station  during  the  period  of  eight  hours  and  to  store  this  the  reservoirs  should  have 
a  capacity  of  065,000,000  gallons.  The  reservoirs  would  have  a  net  area  of  about  102 
acres,  allowing  about  25  per  cent,  additional  for  walls,  embankments,  pumping  station, 
etc.,  or  say  23  acres. 

A  safe  velocity  of  discharge  through  the  tunnels  would  be  about  6  feet  per  second, 
and  the  rate  of  discharge  per  24  hours  would  be  about  4,000,000,000  gallons;  under 
these  circumstances  four  tunnels  of  18  feet  diameter  each  would  be  required. 

The  point  of  outlet  would  be  about  three  miles  north  of  the  Ambrose  channel 
light  vessel  and  about  five  miles  southeast  of  Rockaway  Point. 

As  far  as  estimates  have  been  made,  it  appears  that  the  plan  of  collecting  the 
sewage  of  New  York  to  a  central  point  and  discharging  it  to  sea  on  outgoing  currents 
would  cost  not  less  than  f 140,600,000.  Of  this  sum,  the  sewers  to  the  central  pump- 
ing station  would  cost  about  $51,000,000,  the  outfall  tunnels  about  $51,000,000,  and 
the  storage  reservoirs  about  $6,650,000;  other  items,  including  engineering  and  con- 
tingencies, about  $18,000,000,  allowing  15  per  cent.,  and  land  about  $2,000,000. 

It  is  possible  that  works  somewhat  similar  to  these  may  be  needed  for  the  remote 
future,  but  for  the  present  no  such  extensive  and  costly  scheme  is  necessary  in  order 
to  remedy  the  existing  conditions  or  is  justified  by  the  promise  of  benefits  which  would 
be  conferred. 

Application  of  the  Sewage  to  Farm  Lands 

If  the  sewage  of  New  York  were  collected  to  a  central  point  to  be  utilized  for 
agricultural  purposes,  it  would  be  difficult  to  find  a  suitable  location  for  the  farms. 
It  is  unlikely  that  the  people  of  New  Jersey  would  consent  to  receive  the  sewage  within 
the  boundaries  of  that  State.  The  land  to  the  north  of  New  York,  in  Westchester 
county  and  beyond,  is  hilly  and  unsuitable  for  irrigation.  The  only  land  which  is 
located  at  a  suitable  elevation  above  the  sea  and  is  of  sufficient  extent  to  receive  the 
large  quantity  of  sewage  which  would  have  to  be  disposed  of  is  on  Long  Island. 

If  the  sewage  were  to  be  carried  to  Long  Island  for  disposal  on  land,  it  should 
be  collected  first  to  a  central  point  and  there  pumped  to  the  irrigation  fields.  A  suit- 
able central  point  would  be  in  the  vicinity  of  Jamaica.  Leading  to  this  place  would 
be  a  main  drainage  system,  including  inter  ceptors,  collectors  and  mains  from  the  vari- 


38  PLANS  FOR  THE  PROTECTION  OF  THE  HARBOR 

ous  parts  of  the  metropolis.  Large  conduits  would  be  needed  to  carry  the  sewage 
from  the  pumping  station  to  the  disposal  fields.  To  accommodate  the  sewage  in 
1940,  three  conduits  with  a  diameter  of  19  feet  each  would  be  necessary. 

The  irrigation  fields  might  begin  in  the  vicinity  of  Amityville,  a  distance  of 
about  30  miles  from  the  New  York  City  Hall.  Any  point  nearer  would  be  unsuitable 
for  the  disposal  of  a  large  quantity  of  sewage  because  of  the  numerous  villages  and 
other  suburban  settlements  which  exist. 

About  175  square  miles  of  land  would  be  needed,  assuming  that  12,000  gallons  of 
sewage  could  be  utilized  per  acre  per  24  hours.  This  is  the  highest  rate  of  disposal 
which  should  be  allowed.  A  tract  of  land  lying  at  a  suitable  elevation  and  possess- 
ing the  proper  quality  of  soil  can  be  found  running  from  Amityville  to  Quogue,  a  dis- 
tance of  about  50  miles. 

From  an  engineering  standpoint,  the  idea  of  applying  sewage  to  the  sandy  soil  of 
Long  Island  is  feasible.  It  is  estimated  that  the  cost  of  the  works  necessary  would  be 
about  $153,000,000,  exclusive  of  farm  land.  The  purchase  of  this  land  would  repre- 
sent a  large  sum  of  money.  Among  the  items  of  expense  included  in  the  estimate  are 
the  sewers  leading  to  the  main  pumping  station  at  Jamaica — $51,000,000;  the  gravity 
conduits  from  Jamaica  to  the  farm  lands — $34,500,000;  the  pumping  stations  at 
New  York  City  and  at  the  farm  lands — about  $13,000,000  each;  and  improve- 
ments on  the  farm  lands — about  $11,000,000.  The  engineering  and  contingencies, 
reckoned  on  a  basis  of  15  per  cent,  would  amount  to  fully  $20,000,000.  In  this  esti- 
mate, as  in  the  studies  for  the  disposal  of  all  New  York's  sewage  at  sea,  the  quantity 
of  sewage  for  the  year  1940  has  been  estimated  to  be  1,330,000,000  gallons  per  24 
hours  and  the  population  9,000,000.  The  sewage  would  be  the  dry  weather  flow  only. 
The  estimates  of  cost  should  be  understood  as  very  rough  approximations. 

Those  persons  who  have  advocated  the  application  of  the  sewage  to  farm  lands 
have  generally  done  so  in  the  belief  that  the  manurial  ingredients  of  the  sewage  could 
in  this  way  be  utilized  and  a  return  made  on  the  cost  of  getting  rid  of  the  sewage. 
It  is  commonly  believed  that  the  sewage  of  a  great  city  should  be  regarded  as  a  val- 
uable asset,  and  that  for  economic  as  well  as  for  sanitary  reasons  the  useful  ingredients 
should  not  be  wasted. 

Scientific  men,  sometimes  of  great  eminence,  have  called  attention  to  the  waste- 
ful habits  which  they  have  observed  in  the  disposal  of  sewage,  and  have  warmly  ad- 
vocated the  employment  of  measures  for  recovering  the  nitrogen,  phosphoric  acid  and 
other  forms  of  plant  food  from  sewage.  Liebig  and  Ramsey,  the  great  German  and 
English  chemists,  are  on  record  with  regard  to  this  subject  and  many  persons  are 
familiar  with  the  striking  statements  of  the  novelist  Victor  Hugo  on  the  same  subject. 


PRELIMINARY  CONSIDERATIONS  39 

Numerous  efforts  have  been  made  to  utilize  the  manurial  ingredients  of  sewage, 
but  most  of  these  efforts  have  been  unsuccessful.  The  City  of  Paris  disposes  of  a 
large  part  of  its  sewage  by  application  to  farm  land,  but  it  has  been  found  that  the 
area  of  land  required  and  the  many  difficulties  in  properly  applying  the  sewage  to 
the  soil  make  it  undesirable  that  these  works  shall  be  extended.  The  increasing 
quantities  of  sewage  which  will  be  produced  by  the  growing  population  of  Paris  will, 
in  all  likelihood,  be  disposed  of  in  future  by  intensive  processes  of  purification  in 
which  no  effort  will  be  made  to  recover  the  manurial  ingredients.  Experiments  look- 
ing to  this  end  have  been  conducted  by  the  city  for  some  years  and  extensive  works 
on  the  intensive  principle  have  recently  been  put  into  operation  for  a  part  of  the 
suburbs  of  Paris. 

Perhaps  the  most  profitable  example  of  sewage  farms  for  a  great  city  is  afforded 
at  Berlin.  There  the  sewage  is  pumped  from  the  city  through  long  mains  which  ex- 
tend in  various  directions  to  broad  farm  lands  in  the  sandy  plain  surrounding  the 
city.  The  sewage  disposal  fields  are  managed  with  characteristic  German  care  and 
frugality.  Every  effort  is  made  to  turn  the  sewage  to  a  profitable  use,  as  well  as  to 
dispose  of  it  without  nuisance  or  injury  to  health.  The  conditions  of  soil  and  eleva- 
tion of  land  are  particularly  favorable,  and  the  land  when  purchased  for  the  disposal 
of  the  sewage  was  cheap.  The  total  area  of  land  which  it  has  been  necessary  to 
purchase  in  order  to  dispose  of  the  sewage  by  irrigation  is  now  so  great  that  Berlin 
is  regarded  as  one  of  the  largest  land  owners  in  all  of  Germany.  In  Berlin,  as  in 
Paris,  the  application  of  sewage  to  land  has  not  been  found  to  be  a  commercially 
profitable  undertaking  and  it  is  considered  likely  that  intensive  methods  of  purifying 
the  sewage  will,  in  course  of  time,  be  substituted  for  the  sewage  fields. 

There  are  apparently  insuperable  obstacles  to  the  application  of  New  York's 
sewage  to  the  soil  of  Long  Island.  Aside  from  the  great  cost  of  the  works  and  land 
here  mentioned,  it  would  be  necessary  to  eliminate  villages  and  towns  and  require  the 
right  to  the  property  of  many  large  estates  and  public  institutions  or  provide  a  much 
larger  total  area  than  that  mentioned.  More  important  still,  a  part  of  the  water  supply 
of  New  York  might  seriously  be  interfered  with.  Most  of  the  drinking  water  for 
Brooklyn  is  obtained  from  wells  on  the  south  side  of  Long  Island,  and  although  it  is 
possible  that  with  the  additional  water  supply  now  being  brought  to  New  York  from 
the  Catskill  Mountains  the  Long  Island  ground  waters  will  be  given  up  for  Brooklyn, 
it  seems  likely  that  public  opinion  will  not  permit  the  sewage  of  the  metropolis  to  be 
disposed  of  on  the  land  from  beneath  which  such  a  valuable  source  of  wholesome 
drinking  water  is  obtainable.  Finally,  the  south  side  of  Long  Island,  to  which  the 
drainage  would  naturally  have  to  flow,  affords  no  suitable  opportunity  for  the  dis- 


40  PLANS  FOR  THE  PROTECTION  OF  THE  HARBOR 

posal  of  the  effluent.  From  New  York  City,  for  a  distance  of  100  miles,  this  shore  is 
bordered  by  broad,  shallow,  grassy  bays  which  are  extensively  used  for  the  cultivation 
of  shellfish  and  as  a  place  of  recreation  for  people  from  New  York  and  other  cities. 
If  the  application  of  the  sewage  to  the  land  were  conducted  in  the  most  successful 
manner  possible,  so  far  as  the  recovery  of  the  manurial  ingredients  and  the  destruc- 
tion of  harmful  bacteria  are  concerned,  the  effluent  from  the  fields  would  probably 
be  so  rich  in  plant  food  as  to  promote  aquatic  growths  in  the  shallow  bays  to  the  point 
of  nuisance. 

Intensive  Purification  op  the  Sewage 

For  disposal  by  intensive  purification,  the  sewage  could  be  brought  to  a  central 
point  by  such  a  system  of  main  drainage  as  has  already  been  sufficiently  described  in 
discussing  the  possibility  of  discharging  the  sewage  at  sea  or  applying  it  to  farm 
land.  Perhaps  the  best  place  to  which  the  seAvage  could  be  brought  would  be  some- 
where in  the  vicinity  of  Jamaica  bay.  Extensive  areas  of  low-lying  land  at  moderate 
cost  occur  in  this  locality  and  there  is,  perhaps,  less  likelihood  of  producing  objection- 
able nuisance  here  than  anywhere. 

The  process  of  purification  would  presumably  be  settlement  for  the  removal  of 
the  larger  solid  ingredients  and  biological  treatment  for  the  oxidation  of  the  dissolved 
organic  matters.  If  the  sewage  were  to  be  discharged  without  purification  into  the 
waters  of  Jamaica  bay,  a  procedure  which  would  be  undesirable  because  of  the 
shallow,  grassy  nature  of  that  body  of  water  and  from  the  fact  that  large  numbers  of 
persons  might  be  affected  through  the  pollution  of  shellfish,  the  effluent  could  be  dis- 
infected so  that  it  would  be  practically,  if  not  completely,  free  from  disease  germs. 

The  intensive  purification  of  sewage  has  come  into  general  use  in  recent  years.  Its 
sole  object  is  to  dispose  of  those  organic  properties  of  sewage  which  cause  offense 
when  the  sewage  is  discharged  into  water  in  excessive  quantity  or  put  upon  land  to  an 
amount  beyond  the  natural  digestive  capacity  of  the  soil.  As  a  general  thing  no 
effort  is  made  to  recover  the  nitrogen  or  other  useful  property,  the  end  sought  being 
the  sanitary  disposal  of  the  sewage  in  the  most  expeditious  and  inexpensive  manner 
possible.  Many  of  the  largest  cities  employ  intensive  methods  of  sewage  treatment, 
including  London,  Glasgow,  Birmingham,  Manchester,  Salford,  Leeds,  Sheffield,  Ham- 
burg, Frankfort,  Cologne  and  Dresden. 

The  degree  of  purification  accomplished  in  each  case  is  not  the  same,  the  object  in 
designing  the  works  being  to  fit  the  process  to  the  local  situation  in  such  a  way  that 
the  cost  will  not  exceed  the  requirements  of  the  particular  case. 

Included  in  methods  which  may  be  employed  in  the  intensive  purification  are 


PRELIMINARY  CONSIDERATIONS  41 

screens,  settling  basins,  precipitation  tanks,  septic  tanks,  hydrolytic  tanks,  slate  beds, 
contact  beds,  percolating  filters  and  intermittent  filters.  There  are  various  types  of 
apparatus  in  which  these  forms  of  treatment  may  be  carried  out,  and  there  are  some- 
times several  ways  of  operating  the  same  apparatus. 

For  New  York,  if  1,330,000,000  gallons  of  sewage  were  to  be  treated  on  the  shores 
of  Jamaica  bay,  the  process  should  be  as  thorough  and  complete  as  practicable  or  the 
effluent  would  haA-e  to  be  carried  well  out  to  sea.  Estimates  have  been  made  of  the 
cost  of  intensive  treatment,  assuming  that  disinfection  would  not  be  necessary,  but 
that  settlement  in  two-storied  tanks  followed  by  oxidation  in  sprinkling  filters  would 
be  the  most  desirable  process.  The  collection  and  treatment  works  would  cost  ap- 
proximately $141,000,000.  Among  the  principal  items  would  be  the  sewers  leading  to 
the  works  and  the  works  themselves,  each  of  which  items  would  represent  not  less 
than  $50,000,000.  The  pumping  station  would  cost  about  $12,000,000  and  the  outfalls 
not  less  than  $5,000,000.  The  engineering  and  contingencies,  reckoned  on  the  basis 
of  15  per  cent.,  would  amount  to  about  $18,000,000.  This  sum,  in  the  opinion  of  this 
Commission,  is  a  large  price  to  pay  for  the  results  which  would  be  accomplished. 

It  must  be  conceded  that  the  purification  of  sewage  by  the  more  refined  processes 
cannot  be  carried  on  without  risk  of  producing  objectionable  conditions.  Whether 
these  conditions  amount  to  a  nuisance  depends  upon  the  extent  to  which  the  land  in 
the  vicinity  of  the  works  is  occupied  and  the  nature  of  this  occupancy.  Unpleasant 
odors  and  the  presence  of  flies,  while  not  seriously  objectionable  at  a  distance  of  sev- 
eral miles,  would  be  a  source  of  decided  nuisance  in  the  midst  of  a  closely  built-up 
residential  quarter.  The  larger  the  works,  the  more  extensive  the  nuisance  which  would 
be  likely  to  occur.  The  disposal  of  more  than  a  thousand  million  gallons  of  sewage  per 
day  by  means  of  sprinkling  filters  or  contact  beds  could  not  be  accomplished  on  the 
shores  of  Jamaica  bay  or  anywhere  else  within  the  limits  of  New  York  City  without 
giving  rise  to  conditions  so  objectionable  as  to  put  the  idea  of  purifying  the  sewage  in- 
tensively out  of  the  question. 

Partial  Purification  on  an  Island  at  Sea 

Although  it  would  apparently  be  impracticable  to  carry  all  the  sewage  of  New 
York  sufficiently  far  to  sea  to  permit  it  to  he  discharged  in  crude  condition  and  equally 
inadmissible  to  highly  purify  so  large  a  volume  of  sewage  within  those  sections  of  New 
York  which  are  already  thickly  built  up  or  likely  to  become  so,  a  combination  of 
ocean  discharge  and  intensive  purification  should  be  considered.  If  the  sewage  could 
be  relieved  of  a  large  part  of  its  potentially  harmful  matter,  it  should  be  possible  to 
discharge  the  effluent  comparatively  close  to  shore,  and  if  the  effluent  could  be  dis- 


42  PLANS  FOR  THE  PROTECTION  OF  THE  HARBOR 

charged  within  a  short  distance  of  the  coast  line,  it  should  be  possible  to  build  an 
island  at  not  too  great  cost  to  withstand  the  destructive  action  of  the  sea.  This  com- 
bination presents  certain  features  which  require  further  discussion. 

As  to  the  location  of  an  island,  the  situation  is  comparatively  simple.  No  island 
now  exists  which  could  be  employed  for  the  required  works.  It  would  be  necessary 
to  build  one  on  the  extensive  sandy  bottom  of  the  sea  as  it  shelves  upward  to  the  shore 
and  approaches  the  entrance  to  New  York  harbor.  The  sandy  bottom  is,  according 
to  the  best  information  available,  of  permanent  configuration.  It  would  apparently 
be  necessary  only  to  deposit  a  mass  of  rip  rap  in  the  form  of  a  wall  and  deposit  rock 
or  earth  or  sand  within  the  enclosure  until  an  island  had  been  formed  of  the  proper 
dimensions.  The  distance  from  shore  should  be  as  great  as  it  would  be  practicable  to 
go  in  constructing  the  tunnel.  Detailed  study  will  probably  show  that  this  distance 
should  not  be  more  than  a  few  miles.  The  further  the  island  was  from  shore,  the 
greater  the  expense  of  constructing  it  and  the  greater  the  difficulties  and  cost  of 
building  the  tunnel.  It  is  probable  that  it  would  be  more  economical  to  purify  the 
sewage  to  a  comparatively  great  extent  and  carry  on  the  operation  comparatively  near 
shore  than  to  build  the  island  at  such  a  distance  as  would  permit  the  sewage  to  be  dis- 
charged in  nearly  crude  condition.  Three  general  localities  appear  possible  as  the  sites 
for  an  artificial  island.  The  one  further  at  sea  is  where  the  Ambrose  channel  light  vessel 
is  situated  approximately  in  longitude  73  degrees  50  minutes  and  latitude  40  degrees  28 
minutes.  There  is  here  extensive  shoaling  due  apparently  to  continued  discharge  of 
cellar  dirt  and  other  heavy  refuse  dumped  from  boats  engaged  in  carrying  this  material 
from  the  cities  in  the  metropolitan  district.  The  water  at  mean  low  tide  ranges  from 
34  to  60  feet  and  surrounding  this  point  in  all  directions  the  depth  is  over  70  feet. 
To  the  south  and  east  the  water  soon  attains  a  depth  of  100  feet.  To  the  north  and 
west  it  shoals  rapidly  to  depths  of  50  and  40  feet  in  the  direction  of  Rockaway  Point. 
The  distance  from  the  nearest  land  is  7  miles  to  Rockaway  Beach.  This  point,  which 
may  be  termed  Ambrose  shoal,  is  fully  exposed  to  ocean  storms,  and  if  an  artificial 
island  is  constructed  here,  it  would  have  to  be  of  massive  and  correspondingly  costly 
construction.  A  second  point  which  appears  to  be  suitable  for  an  island  is  about  a 
mile  east  of  the  outer  entrance  to  Ambrose  channel  at  40  degrees  30  minutes  by  73 
degrees  55  minutes.  The  water  here  is  about  32  feet  deep  at  mean  low  tide  and  the 
distance  from  shore  is  about  3V2  miles.  Deeper  water  lies  to  the  south  and  east.  The 
ocean  storms  act  directly  and  with  unabated  force  at  this  point  and  if  an  artificial 
island  were  to  be  constructed  here,  it  would  have  to  be  of  great  strength  to  resist  the 
destructive  action  of  the  waves.  Considerable  saving  would,  however,  be  effected  over 
the  cost  of  an  island  at  Ambrose  shoal  because  of  less  depth  of  water  to  be  filled  and 


PRELIMINARY  CONSIDERATIONS  43 

less  depth  and  length  for  the  sewage  tunnel.  The  amount  of  treatment  necessary  to 
the  sewage  at  Ambrose  shoal  would  be  a  minimum.  Perhaps  no  treatment  whatever 
would  be  required.  Some  treatment  would  be  necessary  if  the  island  were  con- 
structed at  the  point  nearer  shore.  Plain  sedimentation  would  probably  be  sufficient 
at  this  point. 

A  third  location  for  the  island  exists  among  the  shallow  reefs  which  once  formed 
what  was  known  as  the  bar  across  the  harbor  in  Lower  New  York  bay.  Here  the 
water  is  not  over  12  feet  deep  in  places  and  it  would  be  feasible  to  construct  an  arti- 
ficial island  of  large  size  at  comparatively  small  expense.  Deeper  water  lies  in  the 
vicinity.  Tunnels  which  would  carry  the  sewage  from  the  shore  would  have  to  pass 
under  water  which  would  be  not  more  than  23  feet  deep  at  mean  low  tide.  The  dis- 
tance from  shore  would  be  about  3  miles.  The  location  would  be  about  40  degrees 
31  minutes  by  73  degrees  58  minutes.  If  1,330,000,000  gallons  of  sewage  were  to  be 
brought  to  this  point  each  day,  it  would  have  to  be  purified  to  a  very  considerable 
extent. 

This  Commission  considers  that  the  plan  of  collecting  all  the  sewage  to  one 
central  point  is  unnecessary  for  the  reason  that  other  remedies  costing  less  money,  in- 
volving fewer  engineering  and  sanitary  difficulties  and  promising  equally  satisfactory 
results  are  feasible. 


CHAPTER  II 


THE  FOUR  PRINCIPAL  DRAINAGE  DIVISIONS  IN  THAT  PART  OF 
THE  METROPOLITAN  SEWERAGE  DISTRICT  WHICH  LIES 

IN  NEW  YORK  STATE 

In  another  part  of  this  report  a  description  is  given  of  various  ways  in  which  the 
sewage  of  New  York  can  be  collected  to  a  central  point  for  disposal  and  it  is  there 
stated  that  it  is  the  opinion  of  this  Commission  that  Avorks  of  less  magnitude  and  cost 
than  one  great  system  of  main  drainage  can  be  constructed  to  answer  all  the  require- 
ments of  the  harbor  as  a  whole  and  satisfy  the  needs  of  every  locality. 

It  is  desirable  here  to  state  some  of  the  fundamental  considerations  upon  which 
the  necessary  works  for  the  reasonable  protection  of  the  waters  should  be  based,  and 
in  particular  to  describe  the  four  principal  drainage  districts  of  New  York  City  in 
which  the  many  problems  connected  with  the  engineering  works  should  be  laid  out. 

The  division  of  the  territory  into  drainage  areas  is  fundamental  to  the  proper  de- 
sign of  such  large  sewers,  purification  plants  and  outlets  as  are  required.  The  bound- 
aries of  these  divisions  should  coincide  approximately  with  the  principal  natural 
drainage  areas  of  the  land.  The  sewage  should  be  collected  and  treated  in  each  of 
these  divisions  in  such  ways  as  to  afford  all  the  relief  needed  in  the  near  future  and  the 
design  of  the  works  should  be  such  as  to  afford  a  more  and  more  complete  protection 
as  the  needs  of  the  future  may  demonstrate.  The  quantities  of  sewage  produced, 
the  facilities  which  are  open  in  the  several  localities  for  disposing  of  it  in  a  sanitary 
manner  and  considerations  of  cost  should  have  due  weight  in  making  the  plans.  The 
form,  location,  extent,  depth  and  volume  of  the  tidal  water  passing,  the  uses  of  the 
water  for  traffic,  recreation,  shellfish  culture,  bathing  and  other  purposes  and  the 
present  and  probable  future  sanitary  and  aesthetic  requirements  of  the  public  should 
receive  due  attention. 

For  purposes  of  administration  during  the  construction  and  maintenance  of  the 
works,  it  was  at  first  thought  that  the  division  of  the  territory  should  harmonize,  if 
possible,  with  the  separation  of  the  city  into  boroughs,  but  a  rigid  agreement  with  the 
borough  boundaries  was  soon  seen  to  be  impracticable  and  unnecessary.  In  some  cases 
the  natural  drainage  of  two  or  more  boroughs  was  tributary  to  a  main  division  of  the 


THE  FOUR  PRINCIPAL  DRAINAGE  DIVISIONS  45 

harbor  which  it  was  desirable  to  protect.  In  other  cases  it  would  be  necessary  to  gather 
sewage  from  two  or  more  boroughs  to  one  central  point  for  disposal.  Under  such  cir- 
cumstances rigid  adherence  to  borough  lines  as  the  boundaries  for  the  sewerage 
divisions  would  not  be  possible. 

In  separating  the  territory  into  main  sewerage  divisions  the  chief  consideration 
was  to  provide  for  an  adequate  and  economical  protection  of  the  harbor  water  and  to 
accomplish  this  object  this  Commission  has  been  guided  by  the  well-established  en- 
gineering examples  afforded  in  the  successful  protection  of  the  harbors  of  other  great 
cities,  that  is,  by  large  intercepting  sewers,  usually  running  along  the  shore  line  to  well 
situated  central  stations  where  the  sewage  can  be  treated  for  the  removal  of  more  or 
less  of  its  impurities  and  the  effluent  discharged  into  deep,  broad  currents  of  open  tidal 
water. 

The  extent  to  which  the  harbor  needs  protection  has  been  regarded  as  of  funda- 
mental importance  in  these  studies.  The  Commission  has  formed  the  opinion  that  it 
will  not  be  necessary  to  keep  all  the  sewage  out  of  the  harbor,  for  these  waters  can 
absorb  a  large  amount  of  sewage  in  a  harmless  and  inoffensive  manner.  This  capacity 
should  be  fully  utilized  and  the  Commission  has  given  much  time  to  the  study  of  the 
extent  and  way  in  which  this  can  be  done. 

It  has  been  considered  desirable  to  formulate  a  definite  series  of  rules  or  restric- 
tions which  would  serve  as  a  standard  of  purity  or  of  cleanness  for  the  water  and 
form  a  serviceable  guide  in  determining  to  what  extent  the  sewage  should  be  kept 
out  of  the  harbor.  Much  care  was  used  in  preparing  this  standard.  To  assist  in 
drawing  it  up,  this  Commission  invited  a  number  of  prominent  sanitary  experts  from 
various  fields  of  professional  activity  to  give  their  attention  to  certain  specific  ques- 
tions and  put  their  opinions  in  the  form  of  written  reports.  A  standard  of  cleanness 
proposed  by  this  Commission  in  the  light  of  the  opinions  of  the  eight  experts  consulted 
has  been  published  in  a  report  dated  August,  1912,  and  is  to  be  found  in  another  part 
of  this  report. 

Quantity  of  Sewage  Entering  New  York  Harbor 

The  eight  divisions  into  which  New  York  harbor  has  been  separated  for  purposes 
of  study  have  been  described  in  the  Commission's  report  of  August,  1912.  To  these  is 
here  added  a  ninth,  to  include  the  sewage  which  is  naturally  tributary  to  the  Passaic 
and  Hackensack  rivers. 

In  preparing  Table  II,  the  dry-weather  flow  of  sewage  discharged  into  each  divi- 


46 


PLANS  FOR  THE  PROTECTION  OF  THE  HARBOR 


sion  has  been  assumed  to  be  the  same  as  the  volume  of  the  public  water  supplies  of  the 
areas  tributary  to  the  respective  divisions.  Where  future  quantities  are  considered, 
the  sewage  to  be  expected  is  in  most  cases  based  on  the  estimate  of  the  authorities  who 
are  charged  with  the  duty  of  providing  the  public  water  supplies.  The  populations 
for  1910  have  been  taken  from  the  United  States  census  reports;  those  for  1940  are 
based  on  carefully  made  estimates  by  this  Commission,  revised  with  the  latest  informa- 
tion obtainable. 

TABLE  II 

Populations  and  Volumes  of  Sewage  Directly  Tributary  to  the  Several  Divisions 

of  the  Harbor 


Division  of  the  Harbor. 


Harlem  river. 


Hudson  river. 


Upper  East  river. 
Lower  East  river. 

Upper  bay  

Newark  bay  


Kill  van  Kull. 


Jamaica  bay . 


Passaic  and  Hackensack  rivers 
Totals  


Sewage. 


Manhattan . 
Bronx  


Manhattan . 
New  Jersey. 


Bronx . . 
Queens . 


Manhattan . 

Queens  

Brooklyn . .  . 


Bayonne  

Jersey  City. 

Newark  

Elizabeth . . . 


Bayonne. . . 
Richmond . 


Brooklyn . 
Queens . . . 


New  Jersey. . 


Sewage 
Mgd.* 


70 
29 


99 
98 
34 


132 
17 
4 

21 
144 

8 
94 

264 
64 

1.3 
0.8 
10 
1 

13 
1.8 
5 


53 
130 

765 


Year  1910. 


Population. 


522,000 
275,000 

797,000 
726,000 
283,000 

1,009,000 
156,000 
26,000 

182,000 
1,083,000 
60,000 
915,000 

2,058,000 
519,000 

18,000 
6,000 
67,000 
12,000 

103,000 
23,000 
27,000 

50,000 
270,000 
81,000 

351,000 
950,000 

6,019,000 


Gals,  per 
Capita 
per  Day. 


124 


131 


115 


120 
123 


126 


140 


151 
137 


Year  1940. 


Sewage 
Mgd.* 


156 
97 

253 
238 
64 

302 
63 
36 

99 
189 

52 
213 

454 
118 

7.1 
1.1 
18 
3.6 


30 


9 
14 


23 


163 
349 

1,719 


Population. 


960,000 
748,000 

1,708,000 
1,470,000 
470,000 

1,940,000 
452,000 
197,000 

649,000 
1,170,000 

383,000 
1,670,000 

3,223,000 
908,000 

51,000 
8,000 
115,000 
26,000 

200,000 
64,000 
75,000 

139,000 
619,000 
290,000 

909,000 
1,900,000 

11,576,000 


Gals,  per 
Capita 
per  Day. 


148 


156 


152 


141 

130 


150 


165 


180 
184 


'Million  gallons  per  24  hours. 


From  Table  II  it  will  be  seen  that  the  total  quantity  of  house  sewage  tributary  to 
ihe  harbor  in  the  year  1910  was  765,000,000  gallons  per  24  hours,  and  the  population 
supplying  this  sewage  was  6,019,000.   By  1940  the  population  will  be  almost  doubled 


THE  FOUR  PRINCIPAL  DRAINAGE  DIVISIONS 


47 


and  the  quantity  of  sewage  will  be  more  than  doubled.  The  sewage  expected  in  1940 
in  one  day  will  be  enough  to  fill  a  reservoir  one  square  mile  in  area  and  10  feet  deep. 

A  glance  at  Table  II  shows  that  a  proportionate  burden  of  pollution  is  not  placed 
upon  each  division.  The  Lower  East  river  receives  much  more  sewage  than  any  other 
division  in  comparison  with  its  size.  This  will  be  true,  also,  in  1940,  if  nothing  is  done 
to  prevent  it.  At  that  time  over  one-fourth  of  the  total  amount  of  sewage  produced  in 
the  metropolitan  district  will  be  directly  tributary  to  this  stream.  The  increase  which 
will  go  to  this  division  from  Brooklyn  and  Queens  will  be  about  half  the  quantity 
which  was  produced  by  Manhattan  in  1910. 

Table  III  has  been  made  from  data  contained  in  the  report  of  this  Commission, 
dated  August,  1912.  Of  particular  interest  are  the  suspended  organic  and  volatile 
matters. 


TABLE  III 

Assumed  Composition  of  the  Sewage  Which  is  Tributary  to  the  Harbor  on  the 
Basis  of  100  Gallons  per  Capita  per  24  Hours.  The  Quantities  Are  Expressed 
in  Parts  by  Weight  per  Million  of  Water. 


Solid  Matters  

Dissolved  

Suspended  

Organic  and  Volatile  Matters 

Dissolved  

Suspended  


800 
500 
300 
400 
200 
200 


Nitrogenous  

Nitrogen  

Non-Nitrogenous 

Fats,  etc  

Total  Carbon  


150 
15 

250 
50 

200 


The  Four  Divisions  of  New  York  and  Their  Main  Characteristics 

Keeping  in  mind  the  considerations  which  have  affected  the  separation  of  the  terri- 
tory into  divisions  and  remembering  that  sewerage  systems  must  conform  closely  with 
natural  drainage  areas,  the  method  adopted  by  this  Commission  for  separating  the  ter- 
ritory into  main  sewerage  divisions  may  be  easily  comprehended.  The  drainage  areas 
included  within  the  principal  ridges  or  watersheds  have  been  laid  down  on  a  map  and 
these  areas  have  been  formed  into  four  large  groups,  depending  upon  the  part  of  the  har- 
bor into  which  the  drainage  naturally  discharged  (see  Frontispiece).  Hereafter,  these 
groups  will  be  called  by  this  Commission  divisions  and  the  separate  drainage  areas 
within  them,  for  which  a  system  of  main  drainage  has  been  designed  or  considered  as 
properly  tributary  to  a  single  outlet,  will  be  termed  subdivisions.  The  four  main  sewer- 
age divisions  will  be  designated  according  to  the  parts  of  the  harbor  to  which  they  are 
tributary.  As  far  as  possible,  the  subdivisions  will  receive  names  which  will  sufficiently 
indicate  their  general  location.     In  one  of  the  divisions,  the  subdivisions  are  so 


48 


PLANS  FOR  THE  PROTECTION  OF  THE  HARBOR 


numerous  and  their  locations  so  impossible  to  indicate  by  distinguishing  names  that 
numbers  arranged  in  consecutive  order  will  be  used. 

The  territory  on  Manhattan  Island  and  in  Brooklyn  which  naturally  drains  into 
the  Lower  East  and  Lower  Hudson  rivers  and  Upper  New  York  bay  constitutes  the 
Lower  East  River,  Hudson  and  Bay  Division. 

The  areas  in  the  Boroughs  of  Queens  and  the  Bronx  which  naturally  drain  into 
the  Upper  East  river,  and  those  parts  of  the  Boroughs  of  Manhattan  and  the  Bronx 
which  naturally  drain  into  the  Harlem  river  constitute  the  Upper  East  River  and 
Harlem  Division. 

The  territory  whose  drainage  flows  or  can  readily  be  made  to  flow  into  Jamaica 
bay  is  called  the  Jamaica  Bay  Division. 

The  territory  in  the  Borough  of  Richmond,  or,  as  it  is  more  generally  termed, 
Staten  Island,  constitutes  the  Richmond  Division. 

These  four  divisions  are  markedly  dissimilar  in  topography,  density  of  popula- 
tion and  in  location  with  respect  to  the  ocean  and  to  large  volumes  of  swiftly-running 
tidal  water,  yet  the  main  drainage  and  sewage  disposal  problems  are  not  greatly  dis- 
similar. 

The  Selection  of  Central  Points  for  Disposal 

Having  tentatively  settled  upon  the  main  divisions,  the  selection  of  the  central 
points  to  which  the  sewage  should  be  collected  for  treatment  and  disposal  became  a 
matter  of  principal  importance.  Upon  the  choice  of  these  points  depends  not  only  the 
cost  of  collecting  the  sewage,  but  the  method  of  treating  it  and  the  facility  with  which 
the  effluent  can  be  disposed  of  after  treatment. 

It  was  considered  by  the  Commission  that  as  far  as  practicable,  the  collection 
point  should  be  near  the  ocean  or  Long  Island  sound  or  close  to  deep  tidal  channels. 
Points  of  outlet  for  untreated  sewage,  if  any  sewage  was  to  be  discharged  in  crude 
condition,  should  never  be  situated  in  shallow,  stagnant,  land-locked  or  remote  parts 
of  the  harbor.  Favorable  conditions  for  a  prompt  dispersion  and  digestion  of  the  sew- 
age matters  should  be  sought.  Where  facilities  were  lacking  for  the  disposal  of  the 
sewage  through  dilution  by  large  volumes  of  freely  flowing  tidal  water,  compensation 
for  this  lack  should  be  made  in  the  degree  of  treatment  given  to  the  sewage  for  the 
removal  of  its  organic  ingredients  before  the  discharge. 

It  was  considered  desirable  to  make  the  number  of  central  points  as  small  as  prac- 
ticable in  order  to  simplify  the  problem  of  administration  and  to  facilitate  the  ulti- 
mate disposal  of  the  sewage,  due  attention  being  given  to  the  probability  that  pumping 
would  have  to  be  employed  to  some  extent  and  to  the  fact  that  for  purposes  of  econ- 
omy of  operation  the  works  should  be  as  compact  and  concentrated  as  is  consistent 
with  due  regard  to  the  first  cost. 

The  exact  degree  of  purification  required  for  the  sewage  could  not  be  stated  when 


THE  FOUR  PRINCIPAL  DRAINAGE  DIVISIONS 


49 


this  method  of  designing  the  works  was  decided  upon,  but  it  was  the  opinion  of  the 
Commission  that  elaborate  processes  and  those  which  required  much  land,  extensive 
apparatus,  patents  and  untried  or  experimental  features  should  be  avoided  as  far  as 
practicable.  As  between  large  first  cost  and  low  running  expenses,  or  small  first  cost 
and  high  maintenance  charges,  the  Commission  favored  the  former  as  likely  to  lead 
to  more  satisfactory  results,  since  the  expenditure  represented  by  the  large  investment 
would  be  made  up  chiefly  of  interest  charges  which  could  be  reckoned  with  in  a 
definite  manner  and  so  free  from  the  uncertainties  of  such  elements  of  expense  as 
are  involved  where  large  quantities  of  supplies  and  labor  are  concerned.  So  far  as 
methods  of  purifying  the  sewage  are  concerned,  the  object  was  to  make  good  use  of 
the  absorptive  capacity  of  the  harbor  waters  and  purify  the  sewage  no  more  com- 
pletely than  was  necessary  in  order  to  satisfy  a  reasonable  standard  of  cleanness.  By 
good  use  is  here  meant  such  use  as  would  do  no  material  harm  to  the  public  health 
and  welfare  either  through  the  production  of  disease  or  nuisance.  To  a  large  extent, 
screens,  grit  chambers  and  similar  methods  of  so-called  preliminary  treatment  should 
be  employed.  Only  in  exceptional  cases  would  the  utmost  degree  of  purification  be 
required. 

Depiniteness  of  the  Plans  and  Estimates 

In  making  the  plans  and  estimates  of  cost  of  the  main  drainage  works  for  the  vari- 
ous divisions,  it  has  not  been  practicable  to  arrange  the  final  details.  The  exact  loca- 
tions of  the  lines  and  their  precise  grades  and  sizes  could  not  be  fixed  without  making 
surveys  and  borings  on  an  extensive  scale.  At  the  same  time,  it  has  been  considered 
desirable  that  the  Commission's  studies  should  be  as  definite  as  practicable  and  to  this 
end  an  effort  has  been  made  to  utilize  the  existing  information  concerning  the  topog- 
raphy, population  to  be  served  and  other  conditions.  Investigations  have  consequently 
been  undertaken  and  efforts  made  to  obtain  from  the  local  sewer  bureaus,  topograph- 
ical bureaus  and  elsewhere  such  data  as  were  available  and  the  plans  here  proposed  are 
largely  based  upon  a  consideration  of  the  facts  so  obtained. 

The  plans  proposed  in  this  report  are  to  be  regarded  as  the  outcome  of  the  Com- 
mission's studies  based  on  the  outlook  in  the  year  1914  for  the  municipal  develop- 
ment of  the  region  under  consideration,  on  the  standard  of  cleanness  which  seems 
necessary  and  sufficient  at  this  time  and  on  the  existing  state  of  the  art  of  sewage 
disposal.  All  the  work  planned  will  not  be  needed  in  the  immediate  future,  but  it  is 
regarded  as  essential  that  such  main  drainage  works  as  are  undertaken  should  con- 
form to  these  general  plans  and  be  made  part  of  the  comprehensive  scheme.  The  pos- 
sibility that  a  more  complete  system  of  protecting  the  waters  than  that  outlined  here 
may  be  needed  in  the  distant  future  has  been  kept  in  mind  in  preparing  the  plans. 
The  works  have  been  intended  to  be  extensible  in  character:  that  part  which  should 
be  undertaken  immediately  may  be  regarded  as  the  beginning  of  a  system  which  will 


50 


PLANS  FOR  THE  PROTECTION  OF  THE  HARBOR 


eventually  be  much  more  complete.  As  greater  protection  is  needed,  it  can  be  secured 
by  extending  the  works  without  undue  sacrifice  of  any  part  of  the  completed  structures. 

In  designing  the  main  drainage  works,  careful  account  has  been  taken  of  the  char- 
acter and  location  of  the  existing  sewers.  Most  of  the  sewers  already  constructed 
by  the  city  were  built  to  accommodate  house,  factory  and  storm  water  drainage.  Where 
no  sewers  have  been  built  or  have  been  designed  and  a  separate  system  seems  more 
suitable,  it  will  be  assumed  that  a  separate  system  will  be  constructed  and  provisions 
have  been  made  in  the  plans  for  main  drainage  for  the  sewage  to  be  collected  in  this 
way. 

In  no  instance  has  this  Commission  concerned  itself  with  the  design  of  the  sewers 
which  will  now  or  in  future  run  through  tbe  streets  to  collect  the  sewage  directly 
from  the  houses.  The  design  of  such  sewers  and  their  maintenance  is  regarded  as  the 
proper  work  of  the  local  sewer  bureaus.  The  main  drainage  works  may  be  contrasted 
with  the  local  sewers  as  offering  a  proper  outlet  for  the  latter:  The  main  sewers  will 
take  the  sewage  wherever  the  local  systems  have  collected  it.  It  is  the  function  of 
the  main  drainage  system  to  protect  the  waters  into  which  the  local  sewers  would 
ordinarily  discharge  and  in  doing  so  they  must  intercept  the  sewage  and  carry  it  to 
centrally  located  points  where  it  may  be  properly  disposed  of.  Most  of  the  sewers 
which  this  Commission  proposes  are  termed  interceptors,  since  they  will  run  along 
the  shore  line  and  intercept  the  sewage  which  otherwise  would  flow  from  the  local 
sewers  to  the  water ;  in  some  cases  the  term  collector  will  be  used  to  designate  a  large 
sewer  which  will  gather  the  sewage  from  inland  areas  and  carry  it  to  proper  points 
for  disposal.  In  a  few  cases  inverted  siphons  will  be  required  to  convey  the  sewage 
across  some  arm  of  the  harbor.  The  term  force  main  is  used  to  indicate  a  line  through 
which  the  sewage  is  pumped  and  the  term  main  sewer  is  used  to  indicate  the  line  lead- 
ing from  an  important  point  of  collection  to  the  outlet. 

Table  IV  contains  various  unit  prices  used  in  the  estimates. 


TABLE  IV 


Unit  Prices  Used  in  Estimating  Cost  of  Main  Drainage  Works 


Brick- Work,  per  cubic  yard  

Cast  Iron  Pipe,  per  ton  

Concrete — Plain,  per  cubic  yard 


$14.00 


26.00 


8.00  to  $10.00 
10.00  "  12.00 
12.00  "  15.00 
.19  "  .25 


Reinforced,  per  cubic  yard. . . . 
In  Baffles,  etc.,  per  cubic  yard 


Dredging,  per  cubic  yard  

Excavation — Depending  on  Conditions. 

Filling  behind  Bulkheads,  per  cubic  yard  

Hauling,  per  ton  mile  

Lumber  in  Foundations,  per  M,  b.m  

Piling,  per  lin.  foot  

Repaying,  per  square  yard  

Rip  Rap,  per  cubic  yard  

Steel  for  Reinforcing,  per  lb  

Tunnel  Excavation,  per  cubic  yard  

Same  when  under  air  pressure,  per  cubic  yard 


30  .00  to  $35  .00 
.30 


6.00  to  $  8.00 
10.00  "  12.00 


1.00 


.50  to$  2.00 
.50  "  1.80 
.02| 


.50 


THE  FOUR  PRINCIPAL  DRAINAGE  DIVISIONS  51 
A  BRIEF  DESCRIPTION  OF  THE  FOUR  DIVISIONS. 

Lower  East  River,  Hudson  and  Bay  Division. 

The  greatest  part  of  the  most  densely  settled  portion  of  New  York  City  is  in- 
cluded in  the  Lower  East  River,  Hudson  and  Bay  Division.  This  includes  all  of 
the  Borough  of  Manhattan  except  that  portion  at  the  northeastern  end  which  nat- 
urally drains  into  the  Harlem  river ;  all  of  the  Borough  of  Brooklyn  except  that  part 
which  naturally  drains  into  Jamaica  bay,  and  the  eastern  end  of  Gravesend  bay ;  and 
that  part  of  the  Borough  of  Queens  which  naturally  drains  into  the  East  river  south 
of  Lawrence  Point  near  Hell  Gate.  To  the  southeast  lies  the  Jamaica  Bay  Division, 
to  the  northeast  the  Upper  East  River  and  Harlem  Division  and  to  the  southwest  the 
Richmond  Division. 

Practically  this  whole  division  is  now  thoroughly  sewered  on  the  combined  plan. 
Sewers  discharge  near  the  level  of  low  tide  and,  except  in  the  Borough  of  Manhattan, 
usually  at  the  bulkhead  or  shore  line.  The  sewers  of  Manhattan,  for  the  most  part, 
are  carried  out  nearly  to  the  outer  ends  of  the  piers  which  project  perpendicularly 
from  the  shores  at  frequent  intervals.  There  are  about  200  sewer  outlets  in  this  divi- 
sion. Nearly  all  the  extensive  shore  line  is  low  and  flat.  The  average  tidal  range  is 
4.4  feet. 

The  waters  into  which  the  crude  sewage  of  this  division  is  now  discharged  are 
those  arms  of  the  harbor  from  which  the  division  takes  its  name.  During  the  dry 
seasons  of  the  year  practically  the  same  water  circulates  back  and  forth  in  the  bay, 
East  river  and  Hudson  river,  which  together  may  be  likened  to  the  stem  and  arms  of 
the  capital  letter  Y.  After  continued  heavy  rains,  the  Hudson  discharges  a  heavy 
flow  of  water  from  the  land  and  this  discharge  of  upland  water  produces  effects  which 
are  visible  in  the  Lower  East  river  and  Upper  bay.  This  change  comes  on  suddenly 
and  causes  the  water  to  appear  turbid  and  brownish  in  color.  Normally  the  water  is 
of  an  olive  green  hue  and  is  slightly  turbid. 

The  Hudson  river  is  a  broad,  deep  waterway  capable  of  accommodating  large  sea- 
going vessels.  Upper  New  York  bay,  while  deep  in  the  main  channels,  contains  exten- 
sive shoals  on  its  east  and  west  sides.  The  shallow  flats  on  the  west  side  underlie 
about  one-third  of  the  entire  water  surface  and  are  covered  with  from  2  to  10  feet  at 
low  tide.  The  Lower  East  river  is  narrower  and  swifter  than  the  Hudson,  but  of  about 
the  same  depth.  The  East  river  is  in  reality  a  strait  which  joins  Upper  New  York 
bay  with  Long  Island  sound. 

The  construction  of  main  drainage  works  in  this  division  are  difficult  by  reason 
of  the  large  quantities  of  sewage  to  be  dealt  with,  the  slight  elevation  of  the  shores 


52 


PLANS  FOR  THE  PROTECTION  OF  THE  HARBOR 


above  tide  water,  the  completeness  with  which  the  territory  is  built  up,  the  large 
amount  of  vehicular  traffic  and  the  great  extent  to  which  structures  have  already  been 
built  beneath  the  surface  of  the  ground. 

Upper  East  River  and  Harlem  Division. 

The  Upper  East  River  and  Harlem  Division  includes  nearly  the  whole  of  the 
Borough  of  the  Bronx,  that  part  of  Manhattan  Island  which  naturally  drains  to  the 
Harlem  river  and  that  part  of  the  Borough  of  Queens  whose  natural  drainage  flows 
to  the  East  river  east  of  Lawrence  Point  near  Hell  Gate.  The  topography  and 
municipal  development  of  this  division  is  various  in  the  extreme.  The  elevation  of 
land  in  the  western  part  of  the  Bronx  is  high,  the  Harlem  river  flowing  for  part  of  its 
way  between  steep  banks.  To  the  east,  steep,  narrow  valleys  run  between  parallel 
ridges  in  a  northerly  and  southerly  direction,  the  land  gradually  becoming  more  uni- 
form in  contour  eastwardly.  The  topography  of  that  part  of  this  division  which  lies 
in  Queens  is  notable  for  its  sloping  land  which  is  situated  at  a  considerable  elevation 
and  for  its  extensive  low-lying  meadows  opening  into  the  East  river.  Both  sides  of  the 
Upper  East  river  are  characterized  by  elevated  promontories  and  deeply  placed  bays. 
A  natural  channel  suitable  for  vessels  of  not  more  than  24  feet  draft  runs  between  the 
headlands  throughout  this  part  of  the  river.  The  rise  and  fall  of  tide  in  the  Upper 
East  river  is  comparatively  great  for  the  metropolitan  territory,  amounting  to  about 
7.5  feet  at  Whitestone. 

The  Harlem  river  joins  the  Hudson  with  the  East  river  and  forms  the  northern 
boundary  of  Manhattan.  It  is  narrow  and  shallow  compared  with  the  other  main 
parts  of  the  harbor,  its  present  use  being  chiefly  for  light  draft  shipping. 

Municipal  conditions  vary  widely  in  this  division.  There  is  an  area  of  several 
square  miles  in  the  southwestern  part  of  the  Bronx  which  is  almost  as  densely  settled 
as  any  part  of  the  City  of  New  York.  There  are  parts  of  Queens  which  possess  every 
semblance  of  rural  remoteness.  Rural  and  semi-rural  conditions  exist  in  parts  of 
this  division.  Isolated  towns  with  large  residence  populations  are  growing  and  will 
doubtless  ultimately  converge,  while  new  centers  are  constantly  being  established 
through  the  efforts  of  enterprising  real  estate  operators.  In  1910  the  population  of 
this  division  was  about  1,103,000.  By  1940  it  is  expected  that  the  population  will  be 
2,400,000. 

Jamaica  Bay  Division. 

The  Jamaica  Bay  Division  faces  the  Atlantic  ocean  and  is  so  situated  that  it  is 
in  little  danger  of  being  affected  by  the  drainage  of  the  rest  of  the  city.  This  division 
is  bounded  by  a  ridge  of  land  which  begins  at  Bensonhurst,  Gravesend  bay,  runs  in  a 


THE  FOUR  PRINCIPAL  DRAINAGE  DIVISIONS  53 

general  northeasterly  direction  to  the  eastern  boundary  of  New  York  City  and  pro- 
ceeds beyond  that  boundary  to  a  point  just  west  of  Roslyn,  where  it  bends  south  and 
extends  to  Lynbrook  and  thence  follows  the  height  of  land  along  the  Rockaway  penin- 
sula to  the  city  line  and  the  ocean.   About  103  square  miles  are  included  in  this  divi- 
sion; of  this,  about  76  square  miles  are  land  and  27  square  miles  water  or  low-lying 
marshy  islands.    Jamaica  bay  is  shallow  except  in  its  southwestern  part,  where  a 
deep  channel  enters  from  the  ocean  and,  dividing  into  numerous  branches,  flows  among 
the  islands.  The  refreshing  action  which  the  tide  produces  upon  the  bay  is  large,  for 
the  bay  is  so  shallow  that  much  of  its  water  leaves  it  at  each  falling  tide  and  is  re- 
placed by  water  from  the  sea  as  the  tide  rises.    The  large  water  surface  favors  the 
absorption  of  oxygen  from  the  atmosphere  and  the  shallow  depth  helps  a  thorough 
mixture  of  the  waters,  two  conditions  which  give  the  bay  considerable  advantage  in 
the  harmless  and  inoffensive  assimilation  of  sewage  matters.  On  the  other  hand,  there 
are  large  areas  of  bottom  exposed  at  low  tide  which  would  become  offensive  if  pol- 
luted by  sewage.    In  the  extensive  shallow  parts  of  the  bay  there  are  dense  growths 
of  vegetable  matter  which,  decomposing,  sometimes  make  a  considerable  demand  upon 
the  dissolved  oxygen  in  the  water.   Probably  four-fifths  of  the  bottom  of  Jamaica  bay 
is  covered  with  black  mud  in  which  vegetable  and  animal  organisms  in  great  variety 
exist. 

Clams,  both  the  soft  shell,  Mya  arenaria,  and  the  hard  shell,  Venus  mercenariam, 
grow  luxuriantly  and  are  taken  from  the  waters  in  large  numbers.  Soft  shell  clams 
are  in  places  taken  under  circumstances  which  lead  to  the  opinion  that  they  are  fre- 
quently polluted. 

Oysters  are  planted  extensively  on  the  harbor  bottom  near  the  sides  of  the  main 
channels  in  the  southern  part  of  the  bay.  The  oysters  grow  well  and  command  good 
prices  in  the  market.  Many  are  eaten  raw,  although  the  typical  oysters  originally  cul- 
tivated in  this  vicinity,  formerly  known  as  Rockaways,  were  large  and  generally  used 
for  cooking. 

Pish  do  not  enter  Jamaica  bay  from  the  ocean  except  in  small  numbers  and  at 
certain  seasons  of  year,  although  there  is  usually  excellent  fishing  in  the  ocean  a  few 
miles  outside  of  the  inlet.  A  numerous  fleet  of  small  fishing  boats  with  headquarters 
inside  the  bay  is  constantly  engaged  in  ocean  angling. 

Much  of  the  territory  in  the  Jamaica  bay  division  is  in  a  state  of  transition  from 
open,  rural  country  to  built-up  city  conditions.  Extensive  sections  along  the 
southern  shore  possess  the  characteristics  of  a  permanent  development. 

It  has  been  proposed  by  the  City  of  New  York  and  National  Government  to  con- 
struct extensive  engineering  works  to  convert  Jamaica  bay  into  a  safe  and  convenient 


54  PLANS  FOR  THE  PROTECTION  OF  THE  HARBOR  • 

harbor  for  ocean-going  vessels  and  if  this  is  done,  as  now  appears  likely,  the  natural 
characteristics  of  the  bay  will,  in  large  part,  give  place  to  deeper,  straighter,  wider 
channels,  canals  and  bulkheaded  shores.  Sewage  now  enters  the  bay  from  a  few  large 
sewers  on  the  northern  and  western  shores  and  from  many  small  outlets  on  the  south. 
The  large  sewers  are  mostly  connected  with  sewage  disposal  works  designed  to  operate 
on  the  principle  of  chemical  precipitation.  These  works  are  all  inefficient  and  have 
repeatedly  been  criticised  adversely  by  and  for  the  Bureau  of  Sewers  of  the  boroughs 
in  which  they  are  situated. 

Richmond  Division. 

The  Richmond  Division  includes  the  whole  of  Staten  Island.  It' has  an  area  of 
about  57  square  miles,  of  which  about  one-sixth  is  marsh  land. 

Staten  Island  is,  in  part,  rough,  high  and  hilly  and,  in  part,  low-lying  and  flat. 
The  high  parts  of  the  island  lie  along  a  broad  ridge  which  extends  in  a  northeasterly 
direction  at  a  distance  of  from  two  to  four  miles  from  the  shores  of  Lower  New  York 
bay. 

The  waters  of  Lower  New  York  bay  are  shallow  for  a  long  distance  seaward  from 
the  Staten  Island  shore.  On  this  account  and  for  the  reason  that  the  shore  is  com- 
paratively inaccessible  by  land  transportation  and  because  of  the  exposure  of  this  part 
of  the  island  to  the  open  sea,  it  seems  likely  that  the  commercial  development  of  this 
water  front  will  long  remain  dormant.  The  south  shore  is  now  occupied  largely  by 
summer  residents  and  by  permanent  settlers  who  live  in  small  villages  near  the  foot 
of  the  hills.  There  are  several  extensively  patronized  bathing  beaches  on  the  south 
shore  of  Staten  Island.  The  west  side  of  the  island,  bordered  by  the  Arthur  Kill,  has 
been  developed  to  some  extent  for  manufacturing. 

The  principal  residence  and  business  parts  of  the  Richmond  Division  lie  at  the 
north  end  of  the  island.  Here  numerous  large  towns  are  situated,  each  fronting  on 
Upper  New  York  bay  or  the  Kill  van  Kull  and  bordered  on  the  other  sides  by  other 
towns  or  the  open  country.  The  business  done  is  chiefly  manufacturing  and  maritime 
and  is  carried  on  close  to  the  water's  edge.  In  the  year  1910  the  population  was  about 
90,000.  The  towns  of  Staten  Island  are  partly  sewered.  There  are  about  30  main  out- 
lets from  which  the  sewage  is  discharged  without  treatment. 


CHAPTER  III 


THE  UPPER  EAST  RIVER  AND  HARLEM  DIVISION 

Topographical  Features  of  the  Division 

The  Harlem  river  and  the  Upper  East  river  determine  the  principal  topographical 
features  of  this  division.  The  Harlem  river  runs  through  a  narrow  valley  with  shores 
which  are  in  part  densely  populated,  or  are  certain  to  become  so  at  no  distant  day. 
The  shores  of  the  Harlem  are  nearly  parallel,  the  stream  resembling,  in  some  respects, 
and  being  actually  in  part,  a  canal.  The  water  is  already  so  overburdened  with  sewage 
that  no  system  of  diffusion  or  other  partial  remedy  is  capable  of  sufficiently  improving 
it.  There  is  not  room  on  the  drainage  area  of  the  Harlem  for  purification  works  capable 
of  sufficiently  improving  the  sewage  to  permit  of  its  discharge  into  these  waters,  and 
consequently  the  sewage  must  be  taken  elsewhere. 

The  shore  lines  on  both  sides  of  the  Upper  East  river  are  markedly  irregular ;  the 
water  surface  being  characterized  by  a  series  of  large,  shallow  bays  along  the  whole 
length,  separated  by  long,  narrow  points  of  land. 

The  water  in  the  main  channel  which  flows  through  the  Upper  East  river  is  not 
now  overburdened  with  sewage,  nor  is  it  likely  soon  to  become  so.  It  has  a  large 
capacity  for  assimilating  sewage,  provided  the  sewage  is  properly  treated  and  then  dis- 
charged directly  at  the  bottom  of  the  tidal  stream. 

The  parts  of  this  territory  which  present  difficulties  to  main  drainage  are  chiefly 
flat,  low-lying  valleys  which  extend  long  distances  inland  from  the  shallow  bays  of  the 
river. 

Except  in  the  closely  built-up  part  of  this  division,  which  is,  or  will  be,  tributary 
to  the  Harlem  river,  the  population  in  the  territory  included  in  this  report  is  chiefly  of 
a  semi-rural  residential  character,  located  in  numerous  growing  villages  not  largely 
devoted  to  manufacturing.  The  future  of  this  division  seems  to  lie  in  its  more  com- 
plete occupation  for  residential  purposes.  The  configuration  of  the  shore,  the  shal- 
lowness of  the  water,  except  in  the  main  channels,  and  the  distance  from  the  metropol- 
itan centers  of  commercial  activity  are  opposed  to  the  extensive  development  of  this 
section  for  the  uses  of  manufacturing  and  transportation. 

Bathing  beaches,  camps  and  other  provisions  for  recreation  at  moderate  expense 
during  the  summer  months  are  now  more  or  less  numerous  and  seem  destined  to  in- 
crease in  popularity  unless  the  pollution  of  the  harbor  water  should  become  so  great 
as  to  be  too  objectionable. 


56  PLANS  FOR  THE  PROTECTION  OF  THE  HARBOR 

Formerly  shell-fish  of  excellent  quality  were  gathered  in  large  number  in  the 
Upper  East  river,  and  even  at  the  present  time  hard-shelled  clams  are  dredged  near 
where  the  river  joins  Long  Island  Sound.  Except  for  small  boats,  yachting,  which 
was,  and  is,  enjoyed  by  many  persons  in  the  Upper  East  river,  has  for  the  most  part 
sought  Long  Island  Sound  for  the  clearer  water,  lesser  tidal  currents  and  greater 
freedom  from  traffic  which  there  prevail. 

Separation  op  the  Division  Into  Five  Parts  for  Main  Drainage  Purposes 

To  facilitate  the  sewerage  and  drainage  of  the  Upper  East  river  and  Harlem  divi- 
sion the  entire  territory  has  been  separated  in  this  report  into  five  subdivisions. 

In  each  subdivision  the  sewage  is  to  be  collected  to  a  central  point  for  treatment 
and  discharge.    The  boundaries  of  the  five  subdivisions  follow: 

1.  The  Harlem  Subdivision  comprises  the  land  in  the  Borough  of  Manhattan, 
north  of  82d  street,  naturally  draining  to  the  Harlem  river,  and  that  part  of  the  Bor- 
ough of  the  Bronx  lying  west  of  the  Bronx  river,  except  a  narrow  strip  draining  to 
the  Hudson  river. 

2.  The  Eastern  Bronx  Subdivision  comprises  that  part  of  the  Borough  of  the 
Bronx  which  lies  east  of  the  Bronx  river.  Westchester,  Unionport  and  Van  Nest  are 
situated  within  this  area. 

3.  The  Northwestern  Queens  Subdivision  comprises  the  northwestern  part  of  the 
Borough  of  Queens,  draining  mostly  to  Bowery  bay  and  to  the  westerly  shore  of  Flush- 
ing bay,  and  includes  North  Beach,  Woodside,  Steinway  and  a  part  of  Corona. 

4.  The  Corona-Flushing  Subdivision  comprises  that  portion  of  the  Borough  of 
Queens  tributary  to  the  East  river,  which  extends  from  the  southeastern  boundary  of 
subdivision  3  southerly  to  the  main  divide  of  Long  Island  and  easterly  to  a  line  run- 
ning through  Whitestone  and  Ingleside.  Most  of  this  area  lies  in  the  Flushing  creek 
drainage  basin.  Winfield,  Elmhurst,  Corona,  Flushing  and  College  Point  and  parts 
of  Whitestone  are  situated  within  its  limits. 

5.  The  Northeastern  Queens  Subdivision  comprises  that  part  of  the  Borough  of 
Queens,  tributary  to  the  East  river  and  Little  Neck  bay,  which  lies  east  of  the  limits  of 
subdivision  4.  Douglaston,  Bayside  and  the  greater  part  of  Whitestone  are  included 
in  this  area. 

Points  for  Concentration  and  Discharge  of  the  Sewage 

The  sewage  will  be  collected  to  as  many  points  as  there  are  subdivisions. 
The  sewage  of  the  Harlem  subdivision  is  to  be  carried  to  Wards  Island,  where  it  is 
to  be  treated  and  the  effluent  discharged  into  the  swift  currents  of  Hell  Gate. 


THE  UPPER  EAST  RIVER  AND  HARLEM  DIVISION 


57 


The  sewage  of  the  Eastern  Bronx  subdivision  will  be  collected  near  Clason  Point, 
where,  after  treatment,  it  will  be  discharged  into  the  deep  water  of  the  Upper  East 
river. 

The  sewage  of  the  Northwestern  Queens  subdivision  will  be  carried  to  a  point  in 
the  neighborhood  of  Hell  Gate  and  there  discharged. 

The  sewage  of  the  Corona-Flushing  subdivision  will  be  brought  to  Tallman  Island, 
where  treatment  works  can  be  located.  The  sewage  will  be  discharged  into  the  East 
river  under  conditions  favorable  for  diffusion. 

The  sewage  of  the  Northeastern  Queens  subdivision  will  be  carried  to  Cryders 
Point,  just  west  of  Little  bay  and  opposite  Throgs  Neck.  There  the  sewage  can  be 
discharged  into  deep  water  at  the  extreme  east  end  of  the  East  river. 

Methods  of  Treatment 

The  methods  of  treatment  proposed  have  all  been  found  to  give  good  results  else- 
where. They  are  among  the  least  offensive  and  most  economical  methods  and  are  capa- 
ble of  producing  effluents  which,  under  suitable  conditions,  may  safely  be  discharged 
into  the  harbor.    (See  Part  IV,  Chapter  II,  "Sewage  Disposal,"  page  421.) 

With  increasing  populations,  it  is  probable  that  the  time  will  arrive  when  a  more 
thorough  treatment  will  be  desirable  and  this  contingency  has  been  borne  in  mind  in 
the  preparation  of  the  plans  proposed.  The  rate  of  development  of  the  several  subdi- 
visions cannot  be  predicted  with  certainty,  but  if  the  plans  submitted  are  carried  out 
they  will  afford  all  the  protection  the  harbor  will  require  for  the  next  fifty  years  and 
can  thereafter  be  adapted  to  such  changed  conditions  as  may  occur  without  material 
alteration. 

Methods  of  Treatment  Proposed.  After  a  careful  study  of  the  question  of  the 
form  of  treatment  required  for  the  sewage  of  the  Upper  East  river  and  Harlem  divi- 
sion, due  regard  being  had  to  the  needs  of  each  of  the  five  outlets,  the  conclusion  has 
been  reached  that  fine  screening  or  coarse  screening  and  sedimentation  will,  for  some 
years,  give  an  effluent  of  satisfactory  character  for  discharge  into  the  water  of  the 
East  river. 

Where  sedimentation  tanks  are  to  be  used,  coarse  screens  will  be  employed  to  pro- 
tect the  pumping  machinery  and  to  keep  large  floating  matters  from  causing  trouble 
in  the  tanks  and  from  passing  out  through  the  outfall. 

In  all  cases  grit  chambers  will  be  placed  on  the  lines  of  the  main  trunk  sewers  at 
or  near  the  treatment  works.  In  these  chambers  the  sewage  will  be  given  a  settling 
period  of  from  one  to  two  minutes,  the  velocity  being  reduced  sufficiently  to  allow  the 
heavy  mineral  detritus  borne  by  the  sewage  to  be  deposited,  but  not  enough  to  permit 
much  organic  matter  to  settle. 


58 


PLANS  FOR  THE  PROTECTION  OF  THE  HARBOR 


The  grit  chambers  will  afford  protection  to  the  pumps  and  will  keep  the  proposed 
long  and  deep  outfall  pipes  clear  of  gritty  deposits  wherever  sedimentation  tanks  are 
not  used.  Where  sedimentation  tanks  are  planned,  the  grit  chambers  will  first  rid 
the  sewage  of  suspended  matter  of  a  kind  which  would  cause  trouble  and  be  difficult  to 
handle  if  allowed  to  settle  in  the  tanks.  Grit  chambers  are  especially  useful  where 
combined  sewers  are  intercepted  or  form  a  part  of  the  collecting  system,  as  will  largely 
be  the  case  with  the  main  drainage  systems  as  here  proposed  for  New  York  City. 

The  treatment  works  at  Wards  Island,  Clason  Point  and  Tallman  Island,  for  the 
Harlem,  Eastern  Bronx  and  Corona-Flushing  subdivisions,  respectively,  should  consist 
of  grit  chambers,  coarse  screens  and  settling  tanks.  Fine  screens  and  grit  chambers  at 
the  foot  of  Winthrop  avenue,  Long  Island  City,  will  suffice  for  the  treatment  of  the 
sewage  for  the  Northwestern  Queens  subdivision ;  the  sewage  from  the  Northeastern 
Queens  subdivision  should  be  passed  through  grit  chambers  and  fine  screens  at  Cryders 
Point,  Beechurst. 

If  it  were  deemed  necessary  to  purify  the  sewage  from  the  Harlem  subdivision 
to  a  greater  extent  than  would  be  done  by  sedimentation  or  chemical  precipitation,  it 
is  doubtful  if  its  further  purification  could  be  undertaken  either  at  Wards  Island  or 
at  any  other  place  in  the  vicinity.  The  area  of  land  required  for  percolating  filters,  to 
treat  the  large  volume  of  sewage  which  is  to  be  brought  to  Wards  Island,  would  re- 
quire more  land  than  is  available,  and  the  odors  which  might  be  produced  by  their  use 
would  be  objectionable  in  this  location.  Contact  beds  might  be  employed  with  less 
objection,  but  it  is  doubtful  if  sufficient  suitable  land  would  be  available  for  this  pur- 
pose after  a  few  decades. 

The  amount  of  sewage  to  be  discharged  from  Queens  into  the  East  river  at  Win- 
throp avenue,  although  large  in  the  distant  future,  will,  for  many  years,  be  consider- 
ably less  than  the  quantity  brought  to  Tallman  Island.  It  will  never  be  more  than  a 
small  proportion  of  the  amount  to  be  discharged  into  the  river  from  the  Wards 
Island  sedimentation  plant,  only  a  few  hundred  feet  distant  from  Winthrop  avenue. 
In  view  of  this  fact  screening  is  the  only  form  of  treatment  deemed  necessary  for  the 
sewage  of  the  Northwestern  Queens  subdivision.  If  a  more  thorough  treatment  be 
needed  in  the  future,  when  the  volume  of  sewage  becomes  greater,  it  will  be  possible 
to  carry  the  sewage  by  means  of  a  tunnel  under  the  East  river  to  the  disposal  works 
at  Wards  Island ;  or  the  necessary  land  for  a  pumping  station  and  settling  tanks  may 
be  procured  in  the  Borough  of  Queens. 

The  amount  of  sewage  to  be  discharged  at  Cryders  Point  probably  will  always  be 
comparatively  small  and  the  opportunity  for  its  diffusion  and  digestion  in  the  waters 
of  the  East  river  is  favorable ;  therefore  screening  is  the  only  treatment  required  for 
the  sewage  of  the  Northeastern  Queens  subdivision. 


THE  UPPER  EAST  RIVER  AND  HARLEM  DIVISION  59 
Sites  for  Treatment  Works 

Harlem  Subdivision.  After  considering  many  projects  for  the  collection  and  dis- 
posal of  the  sewage  of  this  subdivision  it  becomes  evident  that  it  would  be  uneconom- 
ical to  take  the  sewage  further  from  Hell  Gate,  provided  a  suitable  site  for  treatment 
works  could  be  found  in  that  vicinity. 

For  a  time  it  seemed  likely  that  Rikers  Island  might  offer  every  necessary  facil- 
ity for  the  disposal  of  the  sewage,  not  only  of  the  Harlem,  but  of  most  of  the  other 
subdivisions.  The  area  of  Rikers  Island  is  large  enough  for  any  works  which  might 
be  needed,  the  situation  is  remote  from  inhabited  shores  and  the  island,  as  yet  but  little 
occupied,  already  belongs  to  the  City. 

Upon  investigation  Rikers  Island  was  found  to  be  unsuitable  as  a  site  for  sewage 
disposal  works.  Composed  of  uncompacted  refuse  from  New  York  City,  the  stability 
of  the  island  is  too  uncertain  to  warrant  the  construction  of  the  extensive  engineering 
works  required,  and  large  sums  of  money  would  have  to  be  spent  for  grading  in  order 
to  save  the  excessive  cost  of  pumping  the  large  volume  of  sewage  to  the  present  level 
of  the  island. 

The  island  known  as  Sunken  Meadow  was  examined,  but  was  found  to  require 
too  much  improvement  to  warrant  its  use  as  a  location  for  sewage  disposal  works. 

A  better  and  a  more  satisfactory  location  for  the  works  required  lies  at  the  north- 
east corner  of  Wards  Island.  This  island  is  more  favorably  located  than  Rikers  Island 
in  respect  to  the  economical  collection  of  the  sewage,  and  the  land  at  the  proposed  site  is 
low,  firm  and  of  sufficient  extent  for  such  works  as  will  be  required.  The  island  belongs 
to  the  City  of  New  York  and  is  partly  occupied  by  public  institutions.  No  injury 
would  be  done  by  employing  the  corner  selected  for  treatment  works.  Deep  water  lies 
close  to  the  island ;  the  shore  is  smooth  and  the  currents  are  swift.  The  opportunities 
for  an  immediate  diffusion  of  the  sewage  in  the  water  are  perhaps  better  at  this  place 
than  at  any  other  point  in  the  whole  metropolitan  district,  owing  to  the  mixing  action 
of  the  currents.    (See  Fig.  1.) 

Eastern  Bronx  Subdivision.  Two  large  areas  of  marsh  land,  southwest  and  south- 
east of  Unionport,  were  at  first  considered  as  sites  for  sewage  disposal  works,  each 
being  of  ample  size,  but  both  situated  far  from  deep  water.  A  more  favorable  site  for 
the  location  of  such  disposal  works  as  will  be  needed  for  this  subdivision  exists  near 
Clason  Point,  where  the  ground  is  low  and  firm,  and  the  deep  and  swift  currents  of 
the  main  channel  of  the  Upper  East  river  pass  near  the  shore.  A  large  part  of  the 
sewage  from  this  subdivision  will  be  brought  to  Clason  Point  by  the  drainage  system 
now  under  construction,  and  the  remainder  can  be  collected  at  low  cost. 


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THE  UPPER  EAST  RIVER  AND  HARLEM  DIVISION  61 

Northwestern  Queens  Subdivision.  Most  of  the  land  in  the  Northwestern  Queens 
subdivision  drains  naturally  to  Flushing  and  Bowery  bays,  but  owing  to  the  shallow 
water  and  absence  of  currents  capable  of  mixing  with  the  sewage  and  carrying  it  away, 
there  is  no  point  in  either  bay  where  large  quantities  of  treated  sewage  should  be  dis- 
charged. The  nearest  suitable  point  for  the  discharge  of  the  sewage,  after  the  removal 
of  the  suspended  matter,  is  Hell  Gate,  near  the  foot  of  Winthrop  avenue,  and  directly 
opposite  the  proposed  Wards  Island  treatment  works.  The  volume  of  sewage  to  reach 
this  place  probably  will  be  small  for  many  years,  and  such  land  as  is  needed  for  the 
simple  treatment  required  can  be  procured  without  great  difficulty  or  expense. 

Corona-Flushing  Subdivision.  A  large  proportion  of  the  sewage  of  the  Corona- 
Flushing  subdivision  can  easilv  be  concentrated  near  the  mouth  of  Flushing  creek 
and  the  rest  can  be  collected  by  a  sewer  running  from  that  point  to  Tallman  Island, 
where  treatment  works  should  be  located. 

Tallman  Island  is  the  nearest  point  to  the  mouth  of  Flushing  creek  at  which  treat- 
ment works,  of  a  kind  requiring  the  discharge  of  the  effluent  into  deep  water  and  swift 
currents,  can  satisfactorily  be  placed.  Both  land  and  water  conditions  are  suitable 
at  this  point  for  the  location  of  disposal  works  and  the  discharge  of  the  effluent.  The 
site  is  practically  devoid  of  improvement  and  little  or  no  injury  will  be  caused  to 
future  development  by  such  works  as  are  proposed.  Deep  water  exists  at  a  short  dis- 
tance from  shore,  and  the  volume  and  character  of  water  flowing  past  this  point  are 
favorable  for  the  digestion  of  a  large  quantity  of  sewage. 

The  comparative  ease  with  which  the  sewage  from  that  part  of  the  Flushing  creek 
subdivision  which  lies  west  of  the  creek  can  be  united  with  that  from  the  neighbor- 
hood of  Flushing  and  brought  to  Tallman  Island,  makes  it  desirable  that  such  disposi- 
tion of  the  sewage  should  be  made.  The  sewage  should  not  be  carried  to  Hell  Gate,  for 
this  would  be  more  expensive  and  increase  the  burden  which  the  water  of  the  East 
river  has  to  bear  near  the  densely  populated  districts  of  the  city. 

Northeastern  Queens  Subdivision.  The  only  practicable  place  for  the  discharge 
of  the  sewage  of  the  Northeastern  Queens  subdivision,  unless  intensive  treatment  be 
employed,  is  the  East  river,  between  Whitestone  Point  and  Cryders  Point.  The  latter 
is  the  more  suitable  place  both  for  the  collection  and  the  discharge  of  the  sewage.  The 
East  river  offers  better  opportunities  for  the  reception  of  sewage  off  Cryders  Point 
than  it  offers  at  Tallman  Island  or  Clason  Point.  As  the  amount  of  sewage  will 
probably  be  comparatively  small,  for  at  least  a  great  many  years,  and  the  conditions 
for  the  digestion  of  the  discharged  sewage  by  the  water  are  favorable,  fine  screening  is 
the  only  treatment  deemed  necessary  at  this  point.    There  should  be  no  objection 


62  PLANS  FOR  THE  PROTECTION  OF  THE  HARBOR 

to  the  presence  of  a  screening  plant,  provided  the  appearance  of  the  building  conforms 
with  the  surrounding  development. 

Instead  of  carrying  the  sewage  of  Bayside  and  Douglaston  to  Cryders  Point,  as 
is  here  proposed,  it  is  possible  to  treat  it  on  percolating  filters  which  can  be  built  on 
the  marshes  near  Alley  creek,  but  as  these  might  be  objectionable  to  the  residents  of 
the  neighborhood,  the  plan  is  not  considered  advisable. 

Outlets 

Location  and  Depth.  The  sewage  will  be  discharged  in  every  case  at  a  distance 
from  the  shore,  the  position  of  the  outfall  depending  upon  the  nearest  point  at  which 
water  of  suitable  depth  can  be  found.  It  is  proposed  always  to  have  the  sewage  dis- 
charged at  depths  of  from  30  to  50  feet,  and  in  such  manner  as  to  give  a  favorable 
opportunity  for  its  admixture  with  the  water  of  the  river.  In  order  to  facilitate  dif- 
fusion, it  will  be  desirable  to  discharge  the  sewage  from  each  point  at  more  than  one 
outlet. 

Systems  of  Main  Drainage 
Character  of  Sewers  Proposed.  The  main  collecting  and  intercepting  sewers,  as 
planned  by  the  Commission  for  the  Harlem,  Eastern  Bronx  and  Northwestern  Queens 
subdivisions,  will  carry  only  the  dry-weather  flow  of  the  contributing  combined  sewers, 
already  built  or  to  be  built,  in  these  districts.  They  are  not  designed  to  carry  any  por- 
tion of  the  storm  flow.  Overflows  from  these  main  dry-weather  sewers  will  allow  the 
storm-water  to  pass  directly  to  the  watercourses.  The  Commission  does  not  believe 
that,  in  this  district  at  least,  the  advantage  gained  by  the  treatment  of  the  storm- 
water,  at  the  works  proposed,  would  warrant  the  extra  expense  involved  in  that  pro- 
cedure. 

The  main  collecting  and  intercepting  sewers,  planned  by  the  Commission  for  the 
Corona-Flushing  and  Northeastern  Queens  subdivisions,  will  carry  only  house  sewage. 
In  these  areas  it  is  especially  desirable  that  all  new  sewers  be  built  on  the  separate  sys- 
tem. Throughout  this  territory  few  sewers  of  any  kind  have  as  yet  been  built.  Prac- 
tically the  only  combined  sewers  are  in  the  villages  of  Flushing,  Ingleside,  College 
Point  and  Whitestone.  The  Commission's  plans  and  estimates  for  main  drainage 
systems  in  those  two  subdivisions  have  been  made  so  as  to  utilize  the  existing  sewers 
as  far  as  practicable,  and  on  the  assumption  that  the  dry-weather  flow  from  the  exist- 
ing combined  sewers  would  be  intercepted,  but  that  all  sewers  hereafter  built  tribu- 
tary to  these  systems  would  carry  only  house  sewage. 


THE  UPPER  EAST  RIVER  AND  HARLEM  DIVISION  63 

Relative  Merits  of  Separate  and  Combined  Sewers.  Although  this  Commission  is 
aware  that  the  Board  of  Estimate  and  Apportionment  of  the  City  has  approved  pre- 
liminary drainage  plans  prepared  by  the  Sewer  Bureau  of  Queens  Borough  for  a 
large  portion  of  the  Corona-Flushing  subdivision,  and  that  these  plans  call  for  com- 
bined sewers,  except  in  the  low  lands  where  the  street  grades  to  be  established  make 
combined  sewers  impracticable,  discharging  into  Bowery  bay  all  the  sewage  originat- 
ing west  of  Flushing  creek,  the  Commission  believes  it  to  be  desirable  to  provide  more 
protection  than  these  plans  afford  for  keeping  the  waters  free  from  sewage. 

In  the  judgment  of  the  Commission,  the  character  of  the  territory  and  of  the  neigh- 
boring waters  make  separate,  instead  of  combined,  sewers  generally  advisable  for  the 
Corona-Flushing  and  Northeastern  Queens  subdivisions.  Although  the  growth  of  popu- 
lation in  many  parts  of  this  large  area  has  been  rapid,  and  with  the  extension  and 
betterment  of  transit  facilities  is  likely  to  be  still  more  rapid  in  future,  the  total  pop- 
ulation at  present  is  relatively  small,  and  most  of  it  is  gathered  into  a  number  of  more 
or  less  isolated  residential  communities.  Large  areas  of  unoccupied  land  exist.  Not- 
withstanding the  probable  increase  in  population,  the  several  communities  may  be 
expected  to  preserve  their  separate  identities  for  many  years.  In  these  villages  there 
probably  will  be  only  comparatively  few  parts  which,  in  the  near  future,  will  support 
a  dense  population.  Only  small  portions  of  the  territory  will  need  complete  systems 
of  drains  for  the  removal  of  storm  water.  If  the  house  sewage  is  removed  by  means 
of  separate  sewers,  these  can  be  of  small  size  in  comparison  with  those  that  would  be 
necessary  in  case  storm  water  were  also  to  be  provided  for  in  the  same  system,  where- 
as the  surface  water  may,  in  many  cases,  be  discharged  into  near-by  watercourses,  such 
as  Flushing  creek,  without  harmful  consequences.  Separate  sewers  can  thus  be  made 
to  save  for  the  present  the  cost  of  constructing  the  large  and  long  storm- water  drains 
that  will  be  necessary  when  the  land  around  these  creeks  is  fully  developed.  The  con- 
struction of  some  of  these  long  main  drains  can  be  undertaken  gradually,  as  the  need 
for  them  becomes  evident  through  the  development  of  the  territory. 

Practically  all  the  unsewered  communities  in  the  Corona-Flushing  subdivision  are 
in  need  of  sewers  for  the  removal  of  household  wastes.  But  if  the  house  sewage  from 
these  comparatively  small  and  isolated  centers  of  population  were  to  be  collected  and 
carried  away  in  combined  sewers  large  enough  to  take  care  of  the  storm-water  drainage 
of  the  districts  when  they  shall  have  become  densely  built  up  in  the  future,  not  only 
will  the  present  per  capita  cost  of  construction  be  unnecessarily  high,  but  also  the 
small  dry-weather  flow  in  the  large  sewers  will  cause  deposits  to  form  on  their  bot- 
toms, give  rise  to  septic  conditions  and  make  a  high  cost  for  maintenance. 

It  would  be  inadvisable  to  recommend  the  installation  of  separate  sewers  in  the 


64  PLANS  FOR  THE  PROTECTION  OF  THE  HARBOR 

Harlem  subdivision,  as  the  population  is  practically  all  served  at  present  by  combined 
sewers,  and  future  extensions  of  the  same  character  have  been  planned  to  such  an  ex- 
tent as  to  make  a  recommendation  to  this  effect  unwise. 

In  the  Eastern  Bronx  subdivision,  also,  the  installation  of  separate  sewers  would 
not  be  warranted,  as  much  of  the  drainage  system  is  already  under  construction,  and 
comparatively  little  additional  work  is  necessary  in  order  to  bring  all  the  sewage  of 
the  district  to  Clason  Point. 

Although  the  separate  system  would  be  well  adapted  to  such  a  development  of  the 
land  as  may  be  expected  in  the  Northwestern  Queens  subdivision  for  many  years,  and 
would  also  serve  better  to  protect  Bowery  bay  from  pollution  during  periods  of  storm, 
certain  considerations  make  the  separate  system  inadvisable  in  this  territory.  The 
treatment  which  is  projected  for  the  sewage  in  the  near  future  is  passage  through  grit 
chambers  and  screens.  At  some  future  time  many  parts  of  this  territory  are  likely  to 
be  occupied  by  a  rather  dense  population.  Moreover,  preliminary  plans,  contempla- 
ting the  installation  of  combined  sewers,  have  already  been  made  by  the  Bureau  of 
Sewers  of  the  Borough  of  Queens  and  approved  by  the  Board  of  Estimate  and  Appor- 
tionment. 

Collecting  Sewers  for  the  Harlem  Subdivision.  The  sewage  of  the  Harlem  subdi- 
vision will  be  collected  at  Wards  Island  by  means  of  intercepting  sewers  which  will 
follow  both  banks  of  the  Harlem  river  and  the  north  shore  of  the  Upper  East  river  west 
of  the  Bronx  river,  and  connect  with  Wards  Island  by  means  of  tunnels. 

The  sewage  of  that  portion  of  Manhattan  which  drains  to  the  Harlem  river  be- 
tween 82d  street  and  162d  street  will  be  collected  at  a  point  in  Thomas  Jefferson  Park 
just  south  of  the  corner  of  Pleasant  avenue  and  114th  street.  The  south  intercepting 
sewer  will  run  from  86th  street  and  East  End  avenue  northerly  to  its  junction  with 
the  north  intercepting  sewer  in  Thomas  Jefferson  Park.  In  this  park,  near  the  water- 
front, the  sewage  from  both  of  the  interceptors  will  be  passed  through  grit  chambers 
and  coarse  screens,  and  will  then  be  carried  to  Wards  Island  by  means  of  a  deep  tun- 
nel bored  through  solid  rock. 

The  sewage  of  all  that  portion  of  the  Bronx  which  drains  to  the  Harlem  river  and 
the  Bronx  Kills  will  be  collected  by  an  intercepting  sewer  starting  at  192d  street  and 
following  as  closely  as  practicable  the  easterly  shore  of  the  Harlem  river  at  the  corner 
of  132d  street  and  Willow  avenue.  The  dry-weather  flow  from  Marble  Hill  and  the  ter- 
ritory around  Spuyten  Duyvil  will  be  brought  by  gravity  into  the  existing  Broadway 
sewer,  while  that  from  the  low  land  west  of  Kingsbridge  will  have  to  be  pumped  into 
the  same  sewer,  which  is  to  be  intercepted  at  192d  street. 


THE  UPPER  EAST  RIVER  AND  HARLEM  DIVISION  65 

The  intercepting  sewer  along  the  Bronx  shore  of  the  Harlem  river  will  receive  also 
the  dry- weather  flow  from  those  areas  in  Manhattan  north  of  162d  street  which  drain 
to  the  Harlem  river,  with  the  exception  of  the  sewage  from  a  small  district  at  the  ex- 
treme northern  end  of  the  island  which  can  he  hetter  served  hy  having  its  dry-weather 
flow  pumped  into  a  sewer  at  the  corner  of  Seaman  avenue  and  Hawthorne  street,  from 
which  it  would  find  its  final  outlet  in  the  Hudson  river  at  the  foot  of  Dyckman  street. 
The  sewage  which  is  to  be  carried  from  Manhattan  to  the  Bronx  interceptor  will  be  col- 
lected at  172d  street  and  201st  street  by  short  intercepting  sewers,  passed  through  grit 
chambers  and  coarse  screens  and  siphoned  under  the  Harlem  river. 

That  portion  of  the  Bronx  west  of  the  Bronx  river  which  drains  to  the  Upper 
East  river  will  have  its  dry-weather  sewage  flow  collected  by  an  intercepting  sewer 
running  from  the  vicinity  of  the  Farragut  street  sewer  outlet  at  Hunts  Point  to  the 
corner  of  132d  street  and  Willow  avenue. 

At  132d  street  and  Willow  avenue  the  sewage  from  the  two  Bronx  intercepting 
sewers  will  be  passed  through  grit  chambers  and  coarse  screens  and  then  carried  to 
Wards  Island  by  means  of  two  deep  tunnels  of  the  same  character  as  the  one  bring- 
ing the  sewage  from  Manhattan  to  that  place.  It  will  be  necessary  to  build  only  one 
of  these  tunnels  in  the  near  future. 

As  most  of  the  area  included  in  the  Harlem  subdivision  is  either  closely  built  up 
or  is  rapidly  increasing  in  population,  the  collecting  sewers  have  been  designed  by 
the  Commission  to  take  care  of  the  dry-weather  flow  that  may  ultimately  be  expected. 
The  topography  and  other  conditions  are  such  as  to  make  adequate  relief  sewers  ex- 
pensive and  difficult  to  construct. 

Allowance  in  the  estimates  has  been  made  for  placing  automatic  regulators  at  the 
points  in  connection  with  the  combined  sewers,  so  as  to  control  the  flow  into  the  inter- 
ceptor from  each  sewer  during  period  of  storm.  Allowance  has  also  been  made  for  the 
cost  of  such  lateral  sewers  as  will  be  necessary  to  bring  to  the  main  intercepting  sewers 
the  dry-weather  flow  from  the  outlets  of  the  combined  sewers.  Most  of  the  combined 
sewers  are  at  such  elevations  that  tide-gates  will  be  required  so  as  to  prevent  harbor 
water  from  entering  the  intercepting  sewers;  and  tide-gates  have  been  taken  into  ac- 
count in  estimating  the  cost  of  the  project. 

A  pumping  station  will  be  located  on  Wards  Island  for  the  purpose  of  pumping 
all  the  sewage  of  the  Harlem  subdivision  into  the  treatment  tanks  to  be  installed  there. 
Final  discharge  of  the  clarified  sewage  will  be  through  tunnels  outletting  into  the  East 
river  opposite  Wards  Island. 


66  PLANS  FOR  THE  PROTECTION  OF  THE  HARBOR 

Collecting  Sewers  for  the  Eastern  Bronx  Subdivision.  The  sewage  from  a  large 
portion  of  the  Eastern  Bronx  subdivision  will  be  collected  at  Clason  Point  by  a  system 
of  combined  sewers  now  under  construction.  These  combined  sewers  will  be  provided 
with  storm-water  overflows  at  various  points  along  the  Bronx  river  and  Westchester 
creek. 

In  accordance  with  plans  outlined  by  the  Bronx  Bureau  of  Sewers,  another  por- 
tion of  this  subdivision,  lying  east  of  Westchester  creek,  will  be  drained  by  a  trunk 
sewer  outletting  at  Old  Ferry  Point;  and  the  sewage  of  the  remainder  of  the  district, 
which  drains  to  Eastchester  bay,  will  be  carried  to  an  outlet  on  the  south  side  of 
Throgs  Neck. 

A  short  intercepting  sewer  and  a  pumping  station  will  be  all  that  is  required  to 
transfer  the  dry-weather  flow  from  the  Old  Ferry  Point  sewer  to  the  sewer  which  is 
to  discharge  at  Clason  Point.  At  a  later  period  another  intercepting  sewer  could  be 
constructed  along  the  waterfront  from  the  pumping  station  to  a  point  near  Throgs 
Neck,  in  order  to  intercept  the  dry-weather  flow  from  the  district  draining  to  East- 
chester bay.  The  cost  of  this  sewer  has  not  been  included  in  the  estimates,  as  it  will 
not  be  necessary  in  the  near  future  at  least. 

The  sewage  thus  collected  at  Clason  Point,  after  passing  through  grit  chambers 
and  coarse  screens,  will  be  pumped  to  treatment  works  located  at  that  place,  and  the 
effluent  discharged  through  submerged  outlets  into  the  East  river. 

The  sewage  of  the  district  draining  to  Eastchester  bay  will  be  discharged 
untreated  into  deep  water  in  the  East  river  close  to  the  junction  of  the  East  river  with 
Long  Island  Sound.  If  at  some  future  time  it  is  thought  advisable  to  discontinue  the 
discharge  of  raw  sewage  at  this  point,  a  connection  can  be  made  with  the  pumping  sta- 
tion at  Westchester  creek,  as  previously  mentioned;  or  treatment  works  can  be  in- 
stalled in  the  vicinity  of  the  outlet. 

Collecting  Sewers  for  the  Northioestern,  Queens  Subdivision.  The  dry-weather 
flow  from  the  Northwestern  Queens  subdivision  will  be  brought  to  the  East  river  at  the 
foot  of  Winthrop  avenue,  Long  Island  City,  by  means  of  an  intercepting  sewer  start- 
ing on  Ditmars  avenue  north  of  Astoria  avenue,  Corona,  and  running  along  the  shores 
of  Flushing  bay  and  Bowery  bay,  passing  thence  through  Steinway  to  its  final  outlet. 
The  sewage  will  be  passed  through  grit  chambers  and  fine  screens  before  being  dis- 
charged. 

With  the  street  grades  as  now  established,  all  the  sewage  of  this  area,  with  the  ex- 
ception of  that  from  several  small  districts  along  the  waterfront,  can  be  discharged 
into  the  East  river  by  gravity.    When  these  districts  are  developed,  several  small 


THE  UPPER  EAST  RIVER  AND  HARLEM  DIVISION  67 

automatic  pumping  stations  can  be  installed  to  pump  the  sewage  into  the  main  inter- 
cepting sewer.  In  order  that  the  dry-weather  flow  from  two  large  interior  districts 
may  be  brought  by  gravity  into  the  main  interceptor,  long  dry-weather  cut-off  sewers 
will  have  to  be  constructed  to  intercept,  at  a  considerable  distance  from  the  water- 
front, the  combined  trunk  sewers  which  are  proposed  for  the  drainage  of  these  dis- 
tricts. The  topography  is  such  that  these  cut-off  sewers  can  intercept  the  dry-weather 
flow  from  the  combined  lateral  sewers  which  will  connect  with  the  main  trunk  sewers 
below  the  points  from  which  the  cut-off  sewers  start. 

Preliminary  drainage  plans  covering  this  territory  have  been  prepared  by  the 
Queens  Borough  Bureau  of  Sewers  and  approved  by  the  Board  of  Estimate  and  Ap- 
portionment. The  plan  proposed  by  the  Commission  interferes  but  little  with  any  of 
the  combined  sewers  proposed  by  the  Bureau,  except  the  main  sewer  along  the  water- 
front, and  affords  a  more  favorable  point  for  the  discharge  of  the  dry-weather  flow. 
The  storm  water  will  be  discharged  directly  into  Flushing  and  Bowery  bays.  The 
main  intercepting  sewers  along  the  shores  of  these  two  bays,  as  proposed  by  the  Bureau 
of  Sewers,  becomes  unnecessary.  Steps  have  been  taken  by  the  Bureau  of  Sewers  to 
build  this  sewer  for  the  present  only  to  a  point  on  the  southwesterly  shore  of  Flushing 
bay,  south  of  the  outlet  from  Jackson  Mill  pond.  This  sewer  will  continue  to  dispose 
of  the  storm  water  from  the  areas  draining  to  the  southwesterly  shore  of  Flushing 
bay,  while  the  dry-weather  flow  from  the  laterals  discharging  into  it  would  be  inter- 
cepted by  the  sewer  proposed  by  this  Commission. 

No  satisfactory  method  of  relieving  the  intercepting  sewer  for  the  Northwestern 
Queens  subdivision,  at  a  reasonable  cost,  is  apparent,  and  therefore  this  sewer  has 
been  designed  by  this  Commission  to  have  sufficient  capacity  to  provide  for  a  dry- 
weather  flow  which  is  not  likely  to  be  exceeded  for  a  great  many  years. 

Collecting  Seivers  for  the  Corona-Flushing  Subdivision.  The  house  sewage  from 
practically  the  whole  Corona-Flushing  subdivision  will  be  brought  to  Tallman  Island 
by  a  main  trunk  sewer  which  will  start  in  Winfield  and  run  through  Elmhurst  and 
across  the  marshes,  south  and  east  of  Corona,  to  Flushing  creek.  The  sewer  will  pass 
under  the  creek  by  means  of  a  siphon  and  will  follow  its  easterly  bank  through  Flush- 
ing. From  this  point  the  sewer  will  cross  the  marsh  to  College  Point  and  continue  to 
Tallman  Island. 

The  sewage  from  the  tributary  areas  will  be  brought  to  the  main  sewer  by  many 
trunk  and  lateral  sewers.  One  of  the  more  important  of  these  branch  sewers  will 
start  near  Forest  Park  and  join  the  main  trunk  sewer  on  the  meadows  not  far  from 
Strongs  Causeway.    Another,  joining  the  main  sewer  just  after  it  crosses  Flushing 


68  PLANS  FOR  THE  PROTECTION  OF  THE  HARBOR 

creek,  will  drain  the  Mill  creek  valley  and  provide  a  much-needed  outlet  for  the  dry- 
weather  flow  from  the  existing  Ingleside  trunk  sewer.  Still  another  sewer,  with  sev- 
eral main  branches,  will  drain  that  part  of  Corona  which  lies  north  of  the  Long 
Island  Railroad  and,  after  passing  under  Flushing  creek  as  a  siphon,  will  join  the  main 
sewer  at  the  corner  of  Broadway  and  Lawrence  street,  Flushing. 

Most  of  College  Point  will  be  drained  by  two  trunk  sewers,  one  of  which  will 
tunnel  through  the  hill  from  the  foot  of  Fifth  avenue,  while  the  course  of  the  other 
will  be  along  the  shore,  serving  the  westerly  and  northerly  portions  of  College  Point. 

After  considerable  study,  it  has  been  found  feasible,  with  the  street  grades  as 
established,  and  with  the  main  sewer  at  reasonable  depth,  to  collect  practically  all  the 
sewage  to  Tallman  Island  without  pumping.  Some  of  the  low  land  near  the  head  of 
Flushing  creek  is  so  far  from  the  main  trunk  sewer  that  its  sewage  will  have  to  be 
pumped  to  that  sewer. 

At  Tallman  Island  the  sewage,  after  passing  through  grit  chambers  and  coarse 
screens,  will  be  pumped  into  the  treatment  tanks  to  be  installed  there.  The  clarified 
effluent  will  be  discharged  into  the  East  river  through  submerged  outlets  at  a  consider- 
able distance  from  shore. 

Favorable  conditions  exist  for  the  future  relief  of  the  main  trunk  sewer  in  this  sub- 
division. This  is  fortunate,  as  the  territory  is  very  large,  the  main  sewer  long  and  the 
present  population  scattered  and  comparatively  small.  The  trunk  sewers  which  will 
join  the  main  sewers,  and  the  main  sewer  itself  west  of  Elmhurst,  have  been  designed 
to  serve  populations  which  are  not  likely  to  be  exceeded  for  many  years. 

A  future  relief  sewer  is  designed  to  start  on  the  Queens  boulevard  at  Caldwell 
avenue,  southeast  of  Elmhurst,  and  run  in  an  easterly  direction,  relieving  the  main 
trunk  sewer  of  practically  all  the  sewage  which  will  flow  into  it  from  the  south  between 
Caldwell  avenue  and  Mill  creek.  This  relief  sewer  will  cross  Flushing  creek  near 
Strongs  Causeway  and  enter  a  pumping  station  to  be  built  near  the  confluence  of  Mill 
and  Flushing  creeks.  The  Mill  creek  valley  sewer  will  also  be  diverted  so  as  to  enter 
the  station. 

From  the  pumping  station  near  the  junction  of  Mill  and  Flushing  creeks,  the 
sewage  will  be  lifted  into  a  high-level  relief  sewer,  which  will  flow  through  Flushing 
and  follow  the  high  land  west  of  YVhitestone  to  the  treatment  works  at  Tallman  Island. 
This  future  high-level  intercepting  sewer  will  be  continued,  above  its  junction  with  the 
force  main  from  the  pumping  station  just  mentioned,  in  a  southerly  and  easterly  di- 
rection through  Flushing,  Ingleside  and  Flushing  Heights.  The  sewage  from  the  high 
land  between  the  Mill  creek  valley  and  Cedar  Grove  Cemetery  may  be  collected  and 
siphoned  across  the  lower  end  of  this  valley  into  the  high-level  sewer  in  Flushing. 


THE  UPPER  EAST  RIVEK  AND  HARLEM  DIVISION  69 

The  high-level  relief  sewers,  just  described,  will  deliver  by  gravity  to  the  treat- 
ment works  the  sewage  from  practically  all  the  high  land  of  the  Corona-Flushing  sub- 
division which  lies  east  of  Flushing  creek. 

The  original  main  trunk  sewer  from  Winfield  to  Tallman  Island  will  be  of  sufficient 
size  to  carry  the  sewage  which,  for  many  years,  may  be  expected  to  originate  within  the 
territory  which  will  not  be  served  in  the  future  by  the  relief  sewers,  as  described.  It 
will  be  large  enough,  moreover,  to  carry  the  sewage  from  the  whole  Corona-Flushing 
subdivision  for  a  long  time. 

Collecting  Sewers  for  the  Northeastern  Queens  Subdivision.  The  sewage  from 
the  Northeastern  Queens  subdivision  will  be  carried  to  Cryders  Point  by  two  main  in- 
tercepting sewers.  One  of  these,  the  Whitestone  interceptor,  will  start  near  the 
waterfront  west  of  Whitestone  Point  and  run  along  the  Whitestone  shore  and  through 
Beechurst  to  Cryders  Point.  Near  Whitestone  Landing  a  trunk  sewer,  draining  a 
large  inland  district  between  Whitestone  and  Ingleside,  will  join  the  intercepting 
sewer. 

The  other  main  intercepting  sewer  will  extend  along  the  shores  of  Little  bay  and 
Little  Neck  bay,  from  Cryders  Point  to  a  point  in  Bayside  just  north  of  Oakland  Lake. 
At  this  place  a  trunk  sewer  will  extend  to  the  west,  draining  the  large  district  between 
Ingleside  and  Bayside.  At  Broadway,  in  Bayside,  the  sewage  from  Douglaston,  Little 
Neck,  and  the  low  land  lying  between  Bayside  and  Douglaston,  Avill  be  received  into 
the  main  intercepting  sewer  through  a  force  main  which  will  run  from  an  automatic, 
electrically-operated  pumping  station  near  Alley  creek.  To  this  pumping  station  the 
sewage  from  Douglaston  and  Little  Neck  will  be  brought  by  an  intercepting  sewer 
starting  east  of  Douglas  Manor  and  following  closely  the  shore  of  Little  Neck  bay  to 
the  pumping  station. 

Practically  all  the  sewage  of  the  Northeastern  Queens  subdivision,  with  the  excep- 
tion of  that  from  Douglaston,  Little  Neck,  and  the  low  lands  around  Alley  creek,  can  be 
brought  to  Cryders  Point,  and  there  passed  through  screens  and  discharged  into  deep 
water  by  gravity.  The  sewage  from  a  very  small  area  near  Whitestone  Landing,  and 
from  several  low-lying  districts  along  the  shore  of  Little  bay  and  Little  Neck  bay,  will 
have  to  be  pumped  into  the  high-level  sewers  when  the  population  on  these  areas  be- 
comes large  enough  to  require  sewerage  facilities.  Also,  a  small  marshy  district  near 
the  city  boundary,  east  of  Douglas  Manor,  cannot  be  drained  into  the  Douglaston  inter- 
cepting sewer.  These  small  districts  will  be  served  by  inexpensive  automatic  pumping 
stations. 

All  the  trunk  and  intercepting  sewers  of  this  subdivision,  excepting  the  lower  end 
of  the  intercepting  sewer  from  Bayside  to  Cryders  Point,  have  been  designed  to  serve 


70  PLANS  FOR  THE  PROTECTION  OF  THE  HARBOR 

a  population  which  is  not  likely  to  be  exceeded  for  many  years.  From  Shore  avenue 
northward  it  is  proposed  to  relieve  this  sewer  by  a  parallel  sewer  running  to  Cryders 
Point,  but  such  a  relief  sewer  will  not  be  necessary  for  a  long  period. 

Areas,  Populations  and  Quantities  op  Sewage 

The  following  table  gives,  for  the  several  subdivisions,  the  areas,  the  estimated 
population  and  average  dry-weather  sewage  flow  upon  which  the  design  of  the  sewers 
was  based,  and  the  capacities  of  treatment  works  which  the  Commission  has  used  as  a 
basis  for  estimating  the  cost  of  the  projects  proposed  for  the  Upper  East  river  and 
Harlem  division: 


TABLE  V 

Areas,  Populations  and  Quantities  of  Sewage 


Subdivision 

Area 
(Without 
Parks, 
etc.), 
Acres 

Population 

Average 
Dry-weather 

Flow  of 
Sewage,  Mgd.* 

Capacity  of 
Treatment 
Works  on 

In  1910, 
from  U.  S. 
Census 

In  1940 
(Esti- 
mated) 

Which 
Sewers 

are 
Designed 
to  serve 

In  1910 

In  1940 

Which 
Sewers 

are  De- 
signed 

to  carry 

Which 
estimate 
is  based, 

Mgd.* 

Eastern  Bronx  

12,100 
10,600 

3,100 
16,800 

5,900 

995,300 
30,300 
10,000 
62,200 
8,000 

2,105,800 
73,600 
28,500 
179,800 
22,900 

2,838,000 

124.4 
3.8 
0.5 
4.0 
0.3 

302.2 
12.8 

5.0 
27.5 

4.5 

404.6 

200 
20 
15 
40 
10 

Northwestern  Queens  

Corona-Flushing  

Northeastern  Queens  

253,000 
282,400 
62,800 

34.0 
39.0 
9.6 

Totals  

48,500 

1,106,800 

2,410,600 

133.0 

352.0 

285 

*  Million  gallons  per  24  hours. 

Preliminary  Estimates  of  Cost  of  Main  Drainage  Works 

The  following  table  gives  a  summary  of  the  estimated  cost  of  construction  and  of 
the  annual  charges  for  maintenance  and  operation  for  the  works  suggested  in  this 
report.   The  costs  of  land  and  rights  of  way  are  not  included. 


TABLE  VI 
Estimates  of  Cost 


Subdivision 

Cost  of  Construction 
Including 
Engineering 

Cost  of  Maintenance 
and  Operation,  In- 
cluding Fixed 
Charges 

$9,814,000 
708,000 

$701,000 
87,000 

352,000 

29,000 

1,961,000 

154,000 

563,000 

42,000 

Totals  

$13,398,000 

$1,013,000 

Plate  I 

The  Upper  East  River  and  Harlem 
Division 


CHAPTER  IV 
THE  RICHMOND  DIVISION 

General  Description  op  the  Territory 

Location  and  Area.  This  report  deals  with  that  part  of  Staten  Island  which 
slopes  toward  the  Narrows,  Upper  bay,  Kill  van  Kull  and  Newark  bay,  or  nearly  the 
whole  of  the  northern  and  northeastern  portions  of  the  Borough  of  Richmond.  This 
territory  includes,  besides  the  natural  drainage  areas  tributary  to  the  bodies  of  water 
mentioned,  a  comparatively  small  area  which  drains  naturally  to  Willow  brook,  and 
thence  to  Fresh  Kills  and  Lower  New  York  bay,  and  from  which  it  is  feasible  and 
desirable  to  carry  the  house  sewage  to  the  Kill  van  Kull  for  final  disposal. 

The  line  bounding  the  district  on  the  south  starts  from  Fort  Wadsworth  at  the 
Narrows,  and  runs  in  a  generally  westerly  direction  through  Arrochar  and  Grasmere, 
across  Todt  hill  and  through  the  grounds  of  the  Richmond  Borough  almshouse,  finally 
reaching  the  village  of  New  Springville.  On  the  west  the  boundary  line  follows 
closely  the  Port  Richmond  road,  passing  through  Bull's  Head  and  Graniteville,  and 
thence  not  far  from  Morningstar  road  to  a  point  south  of  Elm  Park,  from  which  point 
it  follows  the  watershed  along  the  Staten  Island  Rapid  Transit  Railroad,  westerly 
nearly  to  South  avenue,  whence  it  runs  in  a  northwesterly  direction,  crosses  Rich- 
mond terrace  near  Holland  avenue,  and  continues  to  the  shore  of  Newark  bay  east  of 
Howland  Hook. 

Between  this  line  and  the  established  bulkhead  line  bordering  the  Narrows,  Upper 
bay,  the  Kill  van  Kull  and  Newark  bay  there  is  included  an  area  of  9,178  acres,  or 
about  14.3  square  miles,  exclusive  of  cemeteries,  parks,  institutional  property,  U.  S. 
Government  land,  etc.  This  area  is  approximately  equal  to  one-fourth  of  the  total 
land  surface  of  Staten  Island. 

Topographical  Features.  The  topography  of  the  territory  is  varied.  The  part 
which  drains  to  the  northeastern  shore  of  Staten  Island  is  separated  from  that  which 
drains  to  the  north  shore  by  a  high  ridge,  which  traverses  the  island  in  a  general  north- 
easterly and  southwesterly  direction  and  which  rises  at  Todt  hill,  on  the  southern  boun- 
dary of  the  territory,  to  an  elevation  of  409.8  feet  above  the  Richmond  high-water 
datum.  The  slopes  on  the  easterly  side  of  the  ridge,  within  the  limits  of  the  territory, 
are  precipitous.    The  westerly  and  northerly  slopes  are  generally  gradual. 

In  the  western  part  of  the  territory  the  land  is  comparatively  low,  and  in  many 
places,  near  the  watercourses  and  shores,  it  is  swampy.    The  slopes  down  to  these 


72  PLANS  FOR  THE  PROTECTION  OP  THE  HARBOR 

swainpy  areas  are  generally  gradual,  and  the  ridge  marking  the  outline  of  the  district 
on  the  west  is  not  high. 

The  terminal  moraine  forms  a  conspicuous  feature  of  the  topography  in  the  south- 
eastern part  of  the  district.  Along  the  boundary  line  from  Arrochar  to  Grasmere  the 
bare,  rounded  hills  and  numerous  depressions  and  ponds,  characteristic  of  morainic 
topography,  are  especially  noticeable. 

The  land  near  the  shore,  from  Fort  Wadsworth  to  Howland  Hook,  is  made  up 
alternately  of  headlands,  of  varying  height,  and  valleys.  Streams  flow  through  many 
of  these  valleys,  while  in  others  the  natural  watercourses  have  been  replaced  by  sewers. 
Much  of  that  portion  of  the  territory  which  drains  to  the  Kill  van  Kull  lies  within 
the  drainage  area  of  Bodine  creek,  which  is  the  largest  watercourse  in  the  subdivision. 

Population.  Nearly  all  the  more  thickly  settled  part  of  Staten  Island  lies  within 
the  drainage  districts  of  the  Narrows,  Upper  bay,  Kill  van  Kull  and  Newark  bay.  Out 
of  a  total  population  in  the  Borough  of  Richmond,  in  1910,  of  85,969,  this  territory 
contained  an  estimated  population  of  64,320,  or  almost  exactly  three-fourths  of  the 
total.  In  1940  it  is  probable  that  this  area  will  have  no  less  than  140,000  people  out 
of  190,000,  the  minimum  number  that  may  be  expected  to  inhabit  the  borough  at  that 
date. 

While  for  a  number  of  years  previous  to  1905  the  growth  of  population  in  the  bor- 
ough was  slow,  due  to  various  causes,  since  that  date  the  population  has  increased  at 
a  comparatively  rapid  rate.  Owing  to  changed  conditions,  it  seems  reasonable  to  ex- 
pect that  this  rapid  growth  will  continue. 

Development.  The  land  which  lies  near  the  shore  from  Rosebank  almost  to  How- 
land  Hook  is  well  populated,  and  in  some  places  thickly  settled,  but  no  part  of  the 
whole  area  has  a  population  closely  approaching  in  density  that  which  exists  in  most 
of  the  other  boroughs  of  New  York  City.  In  fact,  with  the  exception  of  a  few  centers 
which  are  chiefly  devoted  to  business  purposes,  and  a  number  of  spots  where  buildings 
of  a  poor  class  are  huddled  together,  the  whole  area,  for  a  considerable  distance  back 
from  the  waterfront,  may  be  termed  suburban.  Further  from  the  water  most  of  the 
territory  is  rural  in  character,  and  there  are  large  tracts  which  are  still  wholly  unim- 
proved. 

While  the  populated  sections  will  gradually  extend  farther  and  farther  from  the 
waterfront,  much  of  the  territory  to  the  south  and  southwest  is  likely  to  remain  in  a 
rural  and  unimproved  state  for  many  years.  It  seems  certain  that  the  business  centers 
will  gradually  expand,  although  nearness  to  Manhattan  will  cause  activities  to  be  con- 
fined mostly  to  the  establishment  of  stores  to  supply  the  needs  of  the  local  population. 


THE  RICHMOND  DIVISION  73 

In  course  of  time  docks  and  warehouses  will  undoubtedly  occupy  the  Stapleton  water- 
front, and  water  and  rail  facilities  make  the  north  shore  a  superior  place  for  the 
establishment  of  factories. 

Sewerage  of  the  Territory.  During  the  last  few  years  large  amounts  of  money 
have  been  spent  by  the  borough  in  the  construction  of  sewers.  In  the  areas  which 
drain  to  the  Narrows  and  Upper  bay,  and  along  the  western  part  of  the  north  shore  of 
the  island,  much  progress  has  been  made  in  replacing  old  and  shallow  village  sewers, 
formerly  built  to  take  care  of  the  immediate  needs  for  house  drainage,  by  modern 
systems.  Except  in  some  of  the  low  areas  near  the  waterfront,  these  new  sewers  are  of 
the  combined  type. 

In  much  of  New  Brighton,  and  in  West  New  Brighton  and  Port  Richmond,  the 
old  village  sewers  have  so  far  remained  more  or  less  adequate  to  the  needs  of  the  com- 
munities. Few  if  any,  new  combined  sewers  have  been  constructed,  and  little  has  yet 
been  done  concerning  the  preparation  of  drainage  plans  for  these  areas.  The  natural 
watercourses  which  traverse  those  areas  have  proved  sufficient  for  the  removal  of  the 
storm  water  and  they  can  continue  for  some  time  to  perform  this  service  for  many 
places.  Certainly,  if  the  storm  water  in  the  thickly  settled  areas  near  the  waterfront 
is  removed  by  sewers,  the  run-off  from  the  more  sparsely  settled  upland  territory  can 
be  adequately  provided  for  in  the  natural  watercourses  for  many  years  to  come. 

Wherever  new  and  complete  systems  of  sewers  have  been  installed  the  dry-weather 
flow  has  been  diverted  from  them,  above  mean  high  tide,  and  carried  in  a  pipe  to  mod- 
erately deep  water,  and  the  outlet  for  the  storm  water  has  been  placed  near  the  shore 
line.  It  is  the  intention  of  the  borough  authorities  to  extend  the  dry-weather  and 
storm-water  outfalls  to  the  pierhead  and  bulkhead  lines,  respectively,  when  the  piers 
and  bulkheads  are  built.  By  this  method  of  discharging  the  house  sewage  into  deep 
water  during  dry  weather,  the  shores  near  the  sewer  outlets  have  escaped  much  of 
the  pollution  which  otherwise  would  have  been  inevitable.  Nevertheless  it  is  felt 
that  at  many  points  the  discharge  of  house  sewage  in  a  crude  state,  even  at  the  pier- 
head line,  will  not  be  permissible  much  longer.  For  this  reason  an  experiment  sta- 
tion has  been  established  by  means  of  which  the  most  suitable  method  of  handling  the 
local  sewage  disposal  problem  can  be  studied. 

Separation  op  the  Territory  Into  Subdivisions 

The  topography  of  the  whole  division  is  unfavorable  for  the  collection  of  all  the 
sewage  to  one  central  point  for  disposal.  The  high  ridge  separating  the  areas  draining 
to  the  northeastern  shore  of  the  island  from  those  draining  to  the  north  shore,  the 


74  PLANS  FOR  THE  PROTECTION  OF  THE  HARBOR 

small  areas  of  low  land  in  the  western  end  of  the  division,  the  great  distance  which 
it  would  be  necessary  to  carry  much  of  the  sewage  and  the  amount  of  pumping  re- 
quired are  opposed  to  the  collection  of  the  sewage  at  a  point  near  the  Narrows,  which 
is  the  most  favorable  place  available  for  its  ultimate  discharge. 

While  the  discharge  of  all  the  house  sewage  from  the  northerly  and  northeasterly 
slopes  of  Staten  Island  into  the  Narrows  would  be  desirable,  and  economy  of  operation 
would  result  from  having  only  one  disposal  plant  to  maintain,  it  is  believed  that  the 
benefits  derived  would  not  compensate  sufficiently  for  the  cost  of  carrying  the  sewage 
to  such  a  plant.  Moreover,  it  seems  certain  that  the  Kill  van  Kull,  with  its  deep  water 
and  swift  currents,  would  provide,  for  many  years,  if  not  for  all  time,  a  sufficiently 
favorable  place  for  discharging  the  sewage  from  the  areas  bordering  on  Newark  bay 
and  the  Kill  van  Kull,  after  it  has  been  passed  through  settling  tanks. 

The  territory  with  which  this  report  deals  has  been  subdivided  in  such  a  way  as 
to  facilitate  the  collection  of  the  sewage,  to  provide  for  each  subdivision  a  favorable 
and  adequate  place  for  treatment  works,  and  to  minimize  the  amount  of  pumping 
necessary.  At  the  same  time  care  has  been  taken  not  to  divide  the  territory  to  such 
an  extent  as  to  cause  the  establishment  of  plants  too  small  to  be  operated  economically. 

The  subdivisions,  five  in  number,  have  been  given  names  associated  with  the  points 
chosen  for  the  sites  of  the  respective  treatment  works.  They  are  named  and  described 
as  follows: 

1.  The  Quarantine  Subdivision  comprises  the  area  naturally  draining  to  the  Nar- 
rows from  Fort  Wadsworth  to  the  Marine  Hospital,  Stapleton.  The  settlements 
known  as  Clifton,  Rosebank  and  Fort  Wadsworth  lie  within  its  boundaries. 

2.  The  Stapleton  Subdivision  comprises  the  area  naturally  draining  to  the  Nar- 
rows between  the  Marine  Hospital  and  St.  George.  Tompkinsville,  Stapleton  and 
Concord  lie  within  this  area. 

3.  The  Livingston  Subdivision  comprises  the  area  naturally  draining  to  Upper 
New  York  bay  west  of  St.  George,  and  most  of  that  draining  to  the  Kill  van  Kull  east 
of  a  line  joining  the  southerly  end  of  Silver  Lake,  the  corner  of  Castleton  and  Bement 
avenues,  and  the  northerly  end  of  Elm  Court,  West  New  Brighton.  Sailors'  Snug  Har- 
bor and  the  settlements  of  New  Brighton  and  Livingston  are  included. 

4.  The  West  New  Brighton  Subdivision  comprises,  roughly,  the  area  naturally 
draining  to  the  Kill  van  Kull  between  the  westerly  limit  of  the  Livingston  subdivision 
and  Tower  Hill,  Port  Richmond,  together  with  the  area  draining  to  Willow  brook,  east 


THE  RICHMOND  DIVISION  75 

of  Port  Richmond  road.  West  New  Brighton  and  Castleton  Corners  and  parts  of  Port 
Richmond,  Graniteville,  Bull's  Head  and  New  Springville  are  in  this  subdivision. 

5.  The  Elm  Park  Subdivision  comprises,  roughly,  the  area  naturally  draining  to 
the  Kill  van  Kull  and  Newark  bay  between  Tower  Hill  and  Holland  avenue.  Elm 
Park  and  parts  of  Port  Richmond  and  Mariner's  Harbor  are  within  its  confines. 

The  boundaries  of  the  Quarantine,  Stapleton  and  western  part  of  the  Elm  Park 
subdivisions  are  fixed  by  the  limits  of  the  sewerage  districts  already  outlined  by  the 
engineers  of  the  borough ;  but  the  boundaries  of  the  Livingston  and  West  New  Brighton 
subdivisions,  except  where  bordering  on  the  Stapleton  subdivision,  and  of  the  eastern 
part  of  the  Elm  Park  subdivision,  have  been  placed  by  this  Commission  as  seemed  best 
suited  to  the  main  drainage  plans  to  be  worked  out.  The  limits  agree,  however,  in  a 
general  way,  with  sewerage  districts  which  have  been  outlined,  but  as  yet  only  ap- 
proximately, by  the  engineers  of  the  borough. 

Outline  of  the  Proposed  Plan  for  Main  Drainage 

The  proposed  plan  for  the  Quarantine  subdivision  provides  for  the  collection  of 
the  sewage  by  a  high-level  intercepting  sewer  to  the  foot  of  Nautilus  street,  near  the 
Quarantine  station,  where,  after  passing  through  coarse  screens,  grit  chambers  and 
fine  screens,  it  will  be  discharged  into  the  deep  water  of  the  Narrows.  The  sewage  from 
the  low  land  in  Clifton  will  be  pumped  to  the  high-level  sewer. 

In  the  Stapleton  subdivision  the  sewage  will  be  collected  near  the  foot  of  Water 
street,  Stapleton,  by  high-  and  low-level  sewers,  passed  through  settling  tanks  and  dis- 
charged into  the  Narrows  off  Canal  street. 

The  plan  for  the  Livingston  subdivision  provides  for  the  collection  of  the  sewage, 
mostly  by  high-level  sewers,  to  the  waterfront  at  Kissel  avenue,  Livingston,  where, 
after  being  passed  through  settling  tanks,  it  will  be  discharged  into  deep  water  in  the 
Kill  van  Kull. 

According  to  the  proposed  plan,  the  sewage  from  the  West  New  Brighton  subdivi- 
sion will  be  brought,  by  high-  and  low-level  intercepting  sewers,  to  the  waterfront  near 
the  garbage  incinerator  in  West  New  Brighton,  passed  through  settling  tanks  and  dis- 
charged into  deep  water  in  the  Kill  van  Kull. 

In  the  Elm  Park  subdivision  the  sewage  will  be  collected,  by  high-  and  low-level 
sewers,  to  the  vicinity  of  Newark  avenue  and  Richmond  terrace,  where,  after  being 
passed  through  settling  tanks,  it  will  be  discharged  into  deep  water  in  the  Kill 
van  Kull. 

The  sewers  will  vary  from  8  inches  to  6  feet  9  inches  in  diameter,  and  their  total 
length  will  be  10.88  miles. 


76  PLANS  FOR  THE  PROTECTION  OF  THE  HARBOR 

Main  Drainage  Systems 

Kind  of  Sewers  Proposed.  The  collecting  and  intercepting  sewers,  as  planned  for 
the  five  subdivisions,  are  designed,  primarily,  to  carry  eventually  only  the  dry-weather 
flow  from  the  contributing  sewers,  already  built  or  to  be  built,  in  these  subdivisions. 
Attention  has  been  directed  to  the  fact  that  the  sewers  built  by  the  borough  have  been, 
in  general,  of  the  combined  type,  and  that  future  construction  is  planned  along  the 
same  lines.  This  means  that  during  wet  weather  much  of  the  house  sewage,  mixed 
with  varying  volumes  of  storm  water,  will  continue  to  the  bulkhead  line  without  being 
intercepted,  and  will  there  be  discharged.  The  growth  of  population  to  be  expected 
in  the  borough  has  so  influenced  the  design  of  the  proposed  dry-weather  trunk  sewers 
that  many  of  them  will  assist  materially,  for  a  considerable  period,  in  the  disposal  of 
the  storm  water. 

While  it  would  be  inadvisable  in  those  districts  that  have  already  been  sewered 
by  the  borough  authorities  to  provide  systems  of  separate  sewers,  using  those  already 
built  to  remove  storm  water,  this  Commission  considers  it  desirable,  from  now  on,  to 
construct  sewers  on  the  separate  plan,  and  provide  only  such  storm-water  sewers  as 
are  demanded  from  time  to  time.  Relieved  of  an  admixture  of  house  sewage,  it  is 
likely  that  many  of  these  storm  sewers  might  empty  directly,  for  many  years  to  come, 
into  the  natural  watercourses  which  flow  northerly  into  the  Kill  van  Kull.  The  build- 
ing of  the  comparatively  small  sewers  required  for  the  house  drainage,  and  only  such 
storm-water  sewers  as  are  absolutely  needed,  would  minimize  the  cost  of  sewer  con- 
struction, a  consideration  of  much  weight,  especially  in  view  of  the  fact  that  the  pop- 
ulation which  can  be  assessed  is  small.  Among  other  advantages  which  the  separate 
system  would  possess  may  be  mentioned  better  protection  against  pollution  to  the  water 
near  shore  during  wet  weather  and  less  quantity  of  sewage  to  be  handled  in  the  treat- 
ment works. 

The  plans  here  proposed  have  been  worked  out  on  the  assumption  that  the  present 
policy  of  constructing  combined  sewers  will  be  continued,  but  whether  or  not  this 
policy  is  followed  in  the  areas  to  be  sewered  in  future,  the  principal  features  of  the 
main  drainage  systems  and  of  the  treatment  works  would  be  the  same.  If  the  sewers 
were  built  on  the  separate  system,  however,  connecting  chambers,  overflows,  tide-gates, 
and  perhaps  grit  chambers,  would  be  unnecessary,  and  the  costs  would  be  reduced  to 
that  extent. 

Population  and  Quantity  of  Setvage.  The  sizes  to  be  provided  for  the  main  trunk 
sewers  for  collecting  the  dry-weather  flow  in  localities  similar  in  position  and  condi- 


THE  RICHMOND  DIVISION  77 

tion  to  the  settlements  on  the  northern  and  northeastern  shores  of  Staten  Island 
should  not  depend,  as  has  been  the  case  in  many  cities,  upon  an  estimate  of  popula- 
tion at  any  definite  period,  but  upon  densities  of  population  on  the  tributary  drainage 
areas  which  are  considered  probable  when  the  areas  shall  have  reached  approximately 
their  ultimate  development. 

The  part  of  Staten  Island  included  within  this  division  is  so  near  Manhattan,  and 
there  are  so  many  other  reasons,  including  the  possibility  of  rapid  transit,  which  may 
greatly  accelerate  the  growth  of  population  in  any  part  of  or  throughout  the  district 
that  it  would  be  unwise  to  restrict  the  capacities  of  the  proposed  trunk  sewers  to  suit 
what  now  appears  to  be  the  needs  of  the  district  thirty  years  hence.  The  total  construc- 
tion cost  of  the  sewers  as  designed  will  not  be  a  very  large  sum,  and  the  saving  ef- 
fected by  cutting  down  their  capacities  materially  would  not  be  as  great  as  might  be 
supposed. 

In  order  to  estimate  the  necessary  capacities  of  treatment  works,  pumping  equip- 
ment and  other  parts  of  the  main  drainage  works  that  can  easily  be  added  to  at  later 
periods,  it  is  essential  that  estimates  be  made  of  present  populations  and  sewage  flows. 
The  following  table  presents  these  figures  as  estimated  for  the  various  subdivisions  for 
the  year  1910,  based  on  United  States  Census  figures.  The  areas  of  the  subdivisions 
are  calculated  to  the  established  bulkhead  line,  but  do  not  include  cemeteries,  parks, 
Sailors'  Snug  Harbor,  U.  S.  Government  property,  etc.  The  "area  sewered"  column 
of  the  table  has  no  reference  to  the  actual  area  in  each  subdivision  that  was  provided 
with  sewers  in  1910,  but  the  figures  represent  roughly  the  areas  that  were  fairly  well 
settled  and  might  with  reason  be  provided  with  sewers.  The  populations  estimated 
for  these  sewered  areas  are  the  ones  which  have  been  used  as  a  basis  for  estimating 
the  flow  of  house  sewage.  It  will  be  noticed  that  in  the  low-level  areas  the  whole  pop- 
ulation was  assumed  to  be  served  by  sewers.  The  total  sewage  flow,  manifestly,  is  not 
the  average  daily  amount  of  sewage  that  was  discharged  from  the  sewer  outlets  of  the 
district  during  dry  weather  in  1910,  but  the  figures  represent  a  rough  estimate  of  the 
average  amount  that  might  have  been  expected  under  a  more  complete  development  of 
the  sewerage  systems. 

The  average  flow  of  house  sewage  has  been  assumed  to  be  125  gallons  per  inhabitant 
per  day,  and  the  average  ground-water  leakage  has  been  taken  at  500,000  gallons  per 
square  mile  per  day,  irrespective  of  local  conditions. 


78  PLANS  FOR  THE  PROTECTION  OF  THE  HARBOR 

TABLE  VII 


Population  and  Sewage  Flow  op  the  Five  Subdivisions  in  1910 


Subdivision 

Area, 
Acres 

Area 
Sewered, 
Acres 

Population 

Population 
on 
Sewered 
Area 

House 
Sewage 
Mgd.* 

Ground 
Water 

Leakage 
Mgd.* 

Total 
Sewage 

Flow 
Mgd.* 

1— HIGH  LEVEL  TERRITORY. 


Quarantine  

661 

330 

6,057 

5,500 

0.69 

0.26 

0.95 

Stapleton  

1,532 

600 

16,152 

15,000 

1.40 

0.47 

1.87 

Livingston  

893 

600 

11,183 

10,000 

0.93 

0.47 

1.40 

4,735 

600 

12,409 

10,000 

0.93 

0.47 

1.40 

Elm  Park  

173 

140 

3,580 

3,500 

0.33 

0.11 

0.44 

Totals  

7,994 

2,270 

49,381 

44,000 

4.10 

1.78 

5.88 

2— LOW 

LEVEL  TERRITORY. 

Quarantine  

156 

80 

1,404 

1,404 

0.13 

0.06 

0.19 

Stapleton  

182 

no 

3,241 

3,241 

0.30 

0.09 

0.39 

Livingston  

66 

35 

250 

250 

0.03 

0.03 

0.06 

West  New  Brighton  

321 

240 

5,082 

5,082 

0.47 

0.19 

0.66 

Elm  Park  

459 

280 

4,962 

4,962 

0.46 

0.22 

0.68 

Totals  

1,184 

745 

14,939 

14,939 

1.39 

0.59 

1.98 

TABLE  VIII 

Total  Population  and  Sewage  Flow  of  the  Five  Subdivisions  in  1910 


Subdivision 

Area, 
Acres 

Area 
Sewered, 
Acres 

Population 

Population 
on 
Sewered 
Area 

House 
Sewage 
Mgd.* 

Ground 
Water 

Leakage 
Mgd.* 

Total 
Sewage 

Flow 
Mdg.* 

Quarantine  

Stapleton  

Livingston  

West  New  Brighton  

Elm  Park  

817 
1,714 

959 
5,056 

632 

410 
710 

635 
840 
420 

7,461 
19,393 
11,433 
17,491 

8,542 

6,904 
18,241 
10,250 
15,082 

8,462 

0.64 
1.70 
0.96 
1.40 
0.79 

0.32 
0.56 
0.50 
0.66 
0.33 

0.96 
2.26 
1.46 
2.06 
1.12 

Totals  

9,178 

3,015 

64,320 

58,939 

5.49 

2.37 

7.86 

The  following  table  gives  the  densities  of  population,  total  population  and  average 
sewage  flow  used  in  designing  the  sewers  of  each  subdivision.  All  the  territory  is  as- 
sumed to  be  sewered.  The  area  as  far  as  the  bulkhead  line  has  been  assumed  to  be 
populated.  Much  of  the  ground  near  the  water  will  be  occupied  by  industrial  establish- 
ments instead  of  dwellings,  but  sufficient  allowance  for  the  sewage  flow  from  these  has 
probably  been  made  by  assuming  the  area  populated  throughout. 

TABLE  IX 


Total  Population  and  Sewage  Flow  Used  in  Designing  the  Proposed  Sewers 


Subdivision 

Density 
of 

Population 
per  Acre 

Population 

Average  Sewage  Flow  Mgd.* 

High 
Level 

Low 
Level 

Total 

High 
Level 

Low 
Level 

Total 

Quarantine  

West  New  Brighton  

Elm  Park  

75-100 
70f-150 

75-100 
40J-120 

80-120 

52,870 
112,385 

81,975 
247,960 

18,040 

15,600 
19,870 
6,600 
38,260 
40,060 

68,470 
132,255 

88,575 
286,220 

58,100 

7.12 
15.24 
10.94 
34.69 

2.39 

2.08 
2.63 
0.88 
5.04 
5.37 

9.20 
17.87 
11.82 
39.73 

7.76 

40-150 

513,230 

120,390 

633,620 

70.38 

16.00 

86.38 

*  Million  gallons  per  day  of  24  hours.  t  Average  density  on  1,116  acres. 

t  Average  density  on  1,814  acres.    Average  density  of  50  on  1,283  acres. 


THE  RICHMOND  DIVISION  79 

Collecting  Sewers  for  the  Quarantine  Subdivision.  Most  of  the  sewage  of  the  Quar- 
antine subdivision  will  be  collected  at  the  foot  of  Nautilus  street  by  a  high-level 
intercepting  sewer,  which  will  intercept  the  dry-weather  flow  from  the  combined  sewer 
in  Maple  avenue  at  the  corner  of  Anderson  street  and  pass  through  Anderson  street, 
Chestnut  avenue,  New  York  avenue,  Sylvaton  terrace  and  Bay  street,  and  along  the 
shore  to  Nautilus  street.  On  its  route  it  will  receive  the  flow  from  all  the  territory 
lying  south  and  west  of  its  course. 

The  sewage  from  the  low  land  in  Clifton  will  be  collected  at  the  corner  of  Bay 
street  and  Maple  avenue  by  an  intercepting  sewer  in  Bay  street,  which  will  intercept 
the  dry- weather  flow  from  existing  sewers  in  Norwood  avenue  and  Simonson  avenue. 
At  Bay  street  the  dry-weather  flow  from  the  Maple  avenue  sewer  will  be  diverted,  and 
together  with  the  flow  from  the  Bay  street  intercepting  sewer  will  be  led  into  an  auto- 
matic, electrically-operated  pumping  station  to  be  located  at  this  corner.  From  this 
pumping  station  the  sewage  will  be  pumped  through  a  force  main  in  Bay  street  to  the 
high-level  intercepting  sewer  at  the  corner  of  Bay  street  and  Sylvaton  terrace. 

The  dry-weather  flow  from  the  existing  Nautilus  street  sewer,  which  drains  a  large 
area,  will  be  intercepted  and  carried  by  a  short  connecting  sewer  to  a  junction  with  the 
high-level  sewer  above  mentioned.  The  plan  also  contemplates  the  construction  of  a 
small  high-level  sewer  in  Centre  street  which  will  intercept  the  dry-weather  flow  from 
the  combined  sewer  at  the  corner  of  Norwood  avenue  and  discharge  it  at  Simonson 
avenue,  or  a  short  distance  north  of  it,  into  the  combined  sewer  planned  for  Centre 
street.  It  will  thence  be  carried  to  the  Maple  avenue  sewer  and  finally  into  the  high- 
level  sewers  in  Anderson  street. 

The  proposed  collecting  sewers  in  the  Quarantine  subdivision  vary  from  12  inches 
to  3  feet  3  inches  in  diameter.  Their  total  length,  including  the  force  main,  but  exclu- 
sive of  the  outlet  pipe,  is  1.46  miles. 

Collecting  Seicers  for  the  Stapleton  Subdivision.  A  large  part  of  the  area  in- 
cluded within  the  Stapleton  subdivision  is  at  a  sufficient  elevation  to  permit  its  sewage 
to  be  collected  and  passed  by  gravity  through  tanks  located  in  Stapleton,  but  the  eleva- 
tions of  the  streets  in  the  vicinity  of  the  works  are  so  slight  that  the  sewage  from  the 
high-level  districts  will  have  to  be  carried  to  the  works  in  long  conduits  submerged 
below  the  hydraulic  gradient. 

On  the  north  the  dry-weather  flow  from  the  Arietta  street  sewer  will  be  intercepted 
at  Stuyvesant  place  and  brought,  together  with  sewage  collected  on  its  route,  by  a 
high-level  sewer  passing  through  Stuyvesant  place,  Griffin,  Hannah,  Sarah  Ann,  Van 
Duzer  and  Elizabeth  streets  to  a  point  a  short  distance  east  of  Van  Duzer  street,  from 


80  PLANS  FOR  THE  PROTECTION  OF  THE  HARBOR 

which  place  it  will  be  carried  to  the  treatment  works,  located  on  Front  street  between 
Prospect  street  and  Water  street,  by  a  siphon  passing  through  Elizabeth  street,  rights  of 
way  and  Front  street. 

On  the  south  the  dry-weather  flow  from  the  large  sewer  in  Broad  street  will  be 
intercepted  at  the  corner  of  Canal  and  Broad  streets  and  carried  to  the  treatment 
works  by  a  siphon  passing  through  Canal,  Water  and  Front  streets.  From  the  corner 
of  Riker  and  Broad  streets  a  connection  will  be  laid  in  such  a  way  as  to  join  the  large 
Broad  street  sewer  just  above  the  point  at  which  its  dry-weather  flow  is  intercepted. 

At  Wright  and  Beach  streets  this  siphon  will  have  connections  through  which  the 
dry-weather  flow  from  the  existing  sewers  in  these  streets  will  be  added.  Ample  head 
for  this  purpose  can  be  secured  without  making  these  cut-off  sewers  of  great  length. 

That  part  of  the  sewage  of  the  subdivision  which  cannot  be  passed  through  the 
treatment  works  by  gravity  will  be  brought  to  an  automatic,  electrically-operated 
pumping  station  located  at  the  works.  Here  the  sewage  will  be  raised  by  the  pumps 
to  such  an  elevation  as  to  allow  it  to  pass  through  the  tanks. 

The  two  low-level  intercepting  sewers  required  will  be  built  in  Front  street  and  will 
be  short.  The  one  from  the  north  will  start,  until  its  extension  is  required,  by  inter- 
cepting the  dry- weather  flow  from  the  existing  Elizabeth  street  sewer;  the  one  from  the 
south  will  intercept  the  dry-weather  flow  outlet  sewer  at  present  in  Canal  street,  and 
will  be  joined  by  the  existing  15-inch  sewer  in  Water  street.  It  is  assumed  that  the 
10-inch  sewer  in  Thompson  street,  which  now  creates  foul  conditions  by  discharging 
into  the  dock,  will  be  joined  to  the  sewer  in  Canal  street  and  the  flow  thus  taken  to  the 
treatment  works. 

In  designing  the  high-level  siphons,  the  available  head  was  found  so  small  that  the 
velocities  through  the  siphons  would  have  to  be  less  than  desirable.  They  would  be 
especially  small  for  a  number  of  years.  Trouble  from  this  cause  can  be  obviated  by 
constructing  by-passes  from  these  siphons  to  the  suction  well  of  the  pumping  station  at 
the  treatment  works.  By  means  of  these  by-passes  the  siphons  can  be  easily  and  effect- 
ively flushed. 

It  was  found  best  to  make  the  south  siphon  of  a  capacity  sufficient  to  take  care  of 
the  needs  for  only  a  few  years  with  the  idea  that  one  or  two  more  conduits  can  be  con- 
structed as  required.  With  the  north  siphon  conditions  were  somewhat  different.  It 
will  be  economical  to  provide  this  siphon  with  the  same  capacity  as  that  of  the  intercept- 
ing sewer  leading  to  it.  In  order  to  make  the  velocity  of  sewage  as  great  as  possible 
when  the  flow  is  small,  the  north  siphon  will  consist  of  two  pipes  of  different  sizes,  the 
larger  one  to  come  into  use  automatically  when  the  level  of  the  sewage  in  the  high-level 
sewer  reaches  a  certain  height. 


THE  RICHMOND  DIVISION  81 

Both  the  north  siphon,  of  24-inch  and  18-inch  pipes,  and  the  south  siphon,  of 
24-inch  pipe,  could,  it  is  thought,  be  built  economically  and  properly  of  vitrified  pipe, 
with  bituminous  joints  and  surrounded  by  concrete,  and  the  estimates  have  been  based 
upon  this  type  of  construction. 

The  proposed  collecting  sewers  in  the  Stapleton  subdivision  vary  from  15  inches  to 
2  feet  9  inches  in  diameter.  Their  total  length,  including  siphons,  but  exclusive  of  out- 
let pipe,  is  1.54  miles. 

Collecting  Sewers  for  the  Livingston  Subdivision.  Practically  all  the  sewage  of 
the  Livingston  subdivision  can  be  brought  to  the  treatment  works  at  the  foot  of  Kissel 
avenue  and  passed  through  them  by  gravity. 

The  sewage  from  St.  George  and  New  Brighton  will  be  collected  by  a  high-level  in- 
tercepting sewer,  which  will  start  at  the  corner  of  Jay  and  Wall  streets  and  pass 
through  Jay  street  and  Richmond  terrace  to  the  treatment  works. 

From  the  south  a  high-level  sewer  will  start  at  the  corner  of  Kissel  avenue  and 
Brighton  boulevard  and  pass  through  Kissel  and  Bergen  avenues  and  Health  place  to 
the  treatment  works.  A  branch  of  this  sewer  will  be  constructed  in  Bergen  avenue  be- 
tween Oakland  avenue  and  Health  place. 

A  small  low-level  intercepting  sewer  will  be  built  in  Richmond  terrace  from  Oak- 
land avenue  to  a  small,  automatic,  electrically-operated  pumping  station  located  at  the 
site  of  the  treatment  works. 

In  this  subdivision  the  high-level  sewers  will  have  to  pass  through  low  land  before 
reaching  the  treatment  works.  The  street  grades  in  these  low  areas  have  been  at  least 
tentatively  established.  However,  the  area  is  not  yet  built  up  and  it  will  be  feasible  to 
raise  the  projected  street  grades  wherever  necessary,  so  as  to  give  a  light,  but  sufficient 
cover  over  the  top  of  the  sewers. 

The  proposed  collecting  sewers  in  the  Livingston  subdivision  vary  from  10  inches 
to  3  feet  3  inches  in  diameter.  The  total  length,  exclusive  of  outlet  pipe,  is  2.77  miles. 

Collecting  Sewers  for  the  West  New  Brighton  Subdivision.  The  sewage  of  the 
West  New  Brighton  subdivision  will  be  collected  by  two  high-level  and  two  low-level 
sewers.  Just  before  reaching  the  treatment  works,  which  are  to  be  located  south  of 
Starin  avenue,  between  Bodine  and  Dongan  streets,  the  sewers  join  so  as  to  form  one 
high-level  and  one  low-level  sewer. 

The  east  high-level  intercepting  sewer  will  start  at  the  corner  of  Elm  court  and 
Henderson  avenue  and  pass  through  Henderson  avenue,  Water  street  and  Richmond 
terrace  to  a  junction  with  the  west  high-level  intercepting  sewer. 

The  west,  or  perhaps  better,  the  south  high-level  intercepting  sewer,  has  been 
assumed,  for  the  purposes  of  this  report,  to  start  at  the  proposed  Northfield  boulevard. 


82  PLANS  FOR  THE  PROTECTION  OF  THE  HARBOR 

Its  route  will  be  through  Linnet  street,  Madison  avenue,  Jewett  avenue,  Roberts  street, 
Manor  road,  Castleton  and  Columbia  avenues,  Cedar  and  Bodine  streets  and  Richmond 
terrace,  and  thence  through  the  city's  property  at  the  West  New  Brighton  garbage  in- 
cinerator. A  small  branch  of  this  sewer  will  be  built  in  Palmer  avenue  east  from  He- 
berton  avenue,  so  as  to  intercept  the  sewage  flow  from  the  high  area  west  of  the  latter 
street. 

The  east  low-level  intercepting  sewer  will  start  at  the  foot  of  Broadway,  at  which 
point  it  is  assumed  that  the  flow  from  the  combined  sewers  in  the  low  area  in  the 
vicinity  will  collect,  and  will  pass  through  Richmond  terrace  and  Starin  avenue  to 
Dongan  street,  where  it  will  join  with  the  west  low-level  intercepting  sewer. 

The  sewage  from  a  large  part  of  Port  Richmond  and  the  low  area  in  the  vicinity  of 
Bodine  creek  and  Palmer's  run  will  be  brought  to  an  automatic,  electrically-operated 
pumping  station  at  the  treatment  works  by  the  west  low-level  intercepting  sewer  which 
will  start  in  Richmond  avenue  north  of  Richmond  terrace  and  pass  through  Richmond 
terrace,  Starin  avenue  and  Dongan  street. 

Whether  the  large  undeveloped  areas  in  the  West  New  Brighton  subdivision,  which 
lie  south  of  the  proposed  Northfield  boulevard,  are  finally  sewered  upon  the  separate  or 
upon  the  combined  plan,  all  the  dry-weather  sewage  flow  can  be  brought  by  gravity  to 
the  upper  end  of  the  west  high-level  intercepting  sewer  as  proposed. 

On  account  of  the  large  population  which  eventually  will  occupy  the  extensive  area 
tributary  to  it,  this  sewer  is  much  larger  than  any  of  the  collecting  sewers  in  the  other 
subdvisions,  and  can  serve  for  many  years  to  carry  to  the  waterfront  much  of  the 
storm-water  brought  to  it  by  the  combined  sewers  in  West  New  Brighton.  The  surplus 
storm-water  would  be  led  to  a  trunk  sewer,  which  would  also  collect  the  flow  from  the 
sewers  of  the  low-level  district.  It  is  suggested  that  this  trunk  sewer  be  designed  of 
a  size  sufficient  to  care  for  the  ultimate  dry-weather  flow  of  the  low-level  district  tribu- 
tary to  it,  together  with  only  such  storm-water  as  it  would  probably  have  to  carry  for 
a  few  years,  with  the  idea  that  later,  when  it  becomes  necessary  to  close  up  the  water- 
courses and  provide  artificial  channels  for  the  storm-water  from  the  large  and  now  un- 
developed areas,  a  large  storm-water  sewer  can  be  built  to  the  waterfront. 

The  conditions  in  much  of  this  subdivision,  with  its  numerous  open  watercourses, 
are  such  that  great  economy  would  result  from  the  construction  of  sewers  on  the  sepa- 
rate system.  It  will  be  particularly  desirable,  when  the  time  arrives,  to  sewer  on  the 
separate  system  that  portion  of  this  subdivision  which  lies  south  of  Richmond  turnpike 
and  drains  directly  to  Willow  brook.  When  it  becomes  no  longer  possible  to  provide 
for  the  storm-water  from  this  area  on  the  surface,  it  should  be  emptied  into  Fresh  Kills 
instead  of  being  carried  with  the  house  sewage  all  the  way  to  the  Kill  van  Kull. 


THE  RICHMOND  DIVISION  83 

In  all  the  subdivisions  it  has  been  assumed  that  streets  would  be  opened  and 
graded  according  to  the  plans  at  present  outlined  by  the  borough.  In  this  subdivision 
particularly,  the  routes  of  many  of  the  proposed  sewers  are  laid  out  in  streets  which  are 
not  yet  opened. 

Owing  to  topographical  conditions  in  the  different  subdivisions,  the  high-level 
sewers,  near  their  entrance  to  the  various  treatment  works,  have  had  to  be  placed  lower 
with  reference  to  the  ordinary  sewage  level  in  the  settling  tanks  than  is  desirable.  With 
the  small  amount  of  sewage  that  will  be  carried  through  these  sewers  in  dry  weather  for 
some  time  after  their  construction,  small  velocities  will  occur  in  their  lower  ends.  This 
will  cause  trouble  from  deposits  only  for  a  short  distance,  if  at  all,  in  any  of  the  sewers 
except  the  west  high-level  sewer  of  the  West  New  Brighton  subdivision,  as  all  of  them 
except  the  one  named  are  small  in  size  and  their  grades  are  considerable.  While  the 
dry- weather  flow  is  small  it  might  be  practicable  to  run  the  tanks  with  a  somewhat 
lower  sewage  level  than  that  for  which  they  are  designed.  Opportunity  for  creating  a 
greater  velocity  at  intervals  might  be  afforded  by  a  temporary  lowering  of  the  water 
level  in  the  tanks  or  by  providing  a  by-pass  to  the  pumping  stations,  outfall  pipes  or  to 
storm  or  combined  sewers  at  a  lower  level. 

The  proposed  collecting  sewers  in  the  West  New  Brighton  subdivision  vary  from 
8  inches  to  6  feet  9  inches  in  diameter.  Their  total  length,  exclusive  of  the  outlet  pipe, 
is  3.14  miles. 

Collecting  Sewers  for  the  Elm  Park  Subdivision.  In  the  four  subdivisions  already 
considered  it  has  been  found  practicable  to  collect  and  dispose  of  most  of  the  sewage 
by  gravity.  Conditions  in  the  Elm  Park  subdivision  are  different,  resulting  in  the 
necessity  of  pumping  considerably  more  than  half  the  sewage. 

A  high-level  intercepting  sewer  will  start  at  the  corner  of  Lafayette  avenue  and 
Harrison  avenue,  Port  Richmond,  to  which  point  it  is  assumed  that  a  combined  sewer 
in  Elizabeth  street  and  Harrison  avenue  will  bring  sewage  from  points  as  far  east  as 
Broadway.  The  route  of  the  high-level  sewer  will  be  through  Harrison,  Nicholas  and 
Charles  avenues,  Douglas  street  and  Newark  avenue  to  the  treatment  works  at  the  cor- 
ner of  Newark  avenue  and  Richmond  terrace.  A  short  branch  of  this  sewer  in  Roselle 
and  Monroe  streets,  as  far  as  the  railroad,  will  bring  to  it  the  dry-weather  flow  from 
existing  sewers  in  Monroe  and  Cedar  streets. 

From  the  east  the  sewage  from  the  low-level  district  will  be  brought  to  an  auto- 
matic electrically-operated  pumping  station  at  the  treatment  works  by  a  sewer  in  Rich- 
mond terrace  starting  at  Nicholas  avenue.  From  the  west  the  sewage  will  be  carried 
to  the  pumping  station  by  a  sewer  in  Richmond  terrace.    This  sewer  will  intercept  the 


84  PLANS  FOR  THE  PROTECTION  OF  THE  HARBOR 

dry-weather  flow  from  the  existing  combined  trunk  sewers  in  Harbor  road,  Union 
avenue  and  Housman  avenue. 

The  proposed  collecting  sewers  in  the  Elm  Park  subdivisions  vary  from  8  inches 
to  3  feet  in  diameter.   Their  total  length,  exclusive  of  the  outlet  pipe,  is  1.97  miles. 

Pumping  Stations.  All  the  pumping  stations  in  the  division  will  be  of  the  auto- 
matic, electrically-operated  type.  The  current  for  operating  them  can  be  purchased,  or 
it  might  be  furnished  by  the  garbage  incineration  plants  at  West  New  Brighton  and 
Clifton,  thus  affording  a  desirable  outlet  for  some  of  the  surplus  power  generated  at 
those  plants.  This  surplus  power  would  undoubtedly  be  used  at  the  West  New  Brigh- 
ton sewage  pumping  station,  as  there  would  be  no  expense  for  transmission  at  this 
point.  It  would  also  probably  pay  to  transmit  power  from  the  Clifton  incinerator  to 
the  Maple  avenue  pumping  station  in  the  Quarantine  subdivision.  Whether  it  would 
be  economical  to  transmit  power  from  the  West  New  Brighton  incinerator  to  the  Elm 
Park  and  Livingston  pumping  stations,  and  from  the  Clifton  incinerator  to  the  Staple- 
ton  pumping  station,  would  depend  upon  the  price  for  which  current  could  be  pur- 
chased from  the  light  and  power  company. 

All  the  pumping  equipment  ultimately  necessary  in  these  stations  would  not  be 
required  at  first.    However,  all  pumps  and  motors  should  be  in  duplicate. 

The  following  table  gives  the  average  total  head  pumped  against,  the  estimated 
average  sewage  flow  which  would  have  arrived  at  each  pumping  station  in  1910  under 
the  assumptions  given  in  the  discussion  of  population  and  sewage  flow,  the  average 
sewage  flow  at  each  station  which  was  used  as  a  basis  for  estimating  the  cost  of  opera- 
tion, and  the  aggregate  average  sewage  flow  for  which  the  sewers  leading  to  the  sta- 
tion were  designed. 


TABLE  X 
Main  Pumping  Stations 


Pumping  Station 

Total  Head, 
Feet 

Average  Sewage  Flow — Mgd.* 

Estimated  for 
1910 

Basis  for  Cost 
of  operation 

Contributing 

Sewers 
Designed  for 

10.0 
12.0 
14.0 
13.5 
14.5 

0.19 

0.39 
0.06 
0.66 
0.68 

0.50 
1.00 
0.25 
2.00 
2.00 

2.08 
2.63 
0.88 
5.04 
5.37 

Elm  Park  

1.98 

5.75 

16.00 

*  Million  gallons  per  day  of  24  hours. 


Outlets.  All  the  outlet  pipes  through  which  the  effluent  from  the  various  treat- 
ment works  will  be  discharged  will  extend  into  deep  water  where  the  currents  are  swift. 


THE  RICHMOND  DIVISION  85 

In  the  Quarantine  subdivision  it  is  proposed  to  make  use  of  an  existing  20-inch 
cast-iron  outlet  sewer  which  extends  out  to  a  point  about  225  feet  from  the  present  shore 
line.  This  pipe  will  be  of  sufficient  capacity  to  last  for  many  years,  and  it  should  be 
extended  to,  or  nearly  to,  the  pierhead  line.  When  necessary,  another  outlet  pipe  can 
be  added. 

There  is  at  present  a  3-foot  wood  stave  pipe  running  to  the  outer  end  of  the 
municipal  ferry  pier  at  the  foot  of  Canal  street,  Stapleton,  through  which  pipe  the 
dry-weather  flow  from  the  tributary  sewers  is  carried  to  deep  water.  This  pipe  is  of 
sufficient  size  to  carry  the  effluent  from  the  proposed  Stapleton  treatment  works  for 
many  years,  and  could  be  made  of  use.  When  the  pier  is  extended  to  the  established 
pierhead  line  the  outlet  pipe  should  be  extended  also.  When  necessary  another  out- 
let can  be  built  at  the  foot  of  Prospect  street. 

From  the  Livingston  treatment  works  it  is  proposed  to  lay  a  submerged  24-inch 
cast-iron  pipe  to  deep  water  beyond  the  pierhead  line  and,  when  necessary,  another  out- 
let pipe  can  be  laid. 

Although  greatly  increased  capacity  of  outlets  from  the  West  New  Brighton  treat- 
ment works  will  ultimately  be  needed,  a  3- foot  pipe  will  be  ample  in  size  for  a  long 
time.  It  would  probably  be  practicable  to  lay  a  wood-stave  pipe  under  the  existing 
pier  at  the  foot  of  Bodine  street  and  to  extend  the  outlet  for  some  distance  into  deeper 
water  by  means  of  a  submerged  cast-iron  pipe. 

From  the  Elm  Park  treatment  works  it  is  proposed  to  lay  a  submerged  20-inch 
cast-iron  pipe  into  deep  water  at  a  considerable  distance  beyond  the  pierhead  line. 
This  pipe  will  be  of  sufficient  size  to  last  for  a  number  of  years.  It  can  be  supple- 
mented by  another  pipe  when  greater  capacity  becomes  necessary. 

Treatment  Works 

Forms  of  Treatment  Proposed.  The  form  of  treatment  proposed  for  the  sewage  of 
all  the  subdivisions,  except  the  Quarantine,  is  the  same  and  consists  of  coarse  screening 
and  sedimentation.  A  period  of  about  two  hours  should  be  allowed  for  settlement. 
It  is  believed  that  the  deep  water  and  strong  currents  along  the  shores  of  this 
district  will  afford  ample  opportunity  for  the  diffusion  and  digestion  of  sewage  in  such 
quantities  as  may  be  expected  from  this  portion  of  Staten  Island,  if  it  is  treated  in  the 
manner  proposed,  and  discharged  from  submerged  outlets  into  water  of  30  feet  or  more 
in  depth  and  good  current. 

The  successful  protection  of  the  water  along  these  shores  will,  however,  depend 
somewhat  upon  the  measures  taken  elsewhere  for  the  betterment  of  the  harbor.  The 


86  PLANS  FOR  THE  PROTECTION  OF  THE  HARBOR 

present  pollution  along  the  northern,  and  particularly  the  northeastern,  shore  of  Staten 
Island  is,  to  some  extent,  due  to  the  condition  of  the  harbor  water  in  general. 

Passage  through  grit  basins,  coarse  and  fine  screens  is  the  form  of  treatment  pro- 
posed for  the  Quarantine  subdivision,  as  the  opportunity  for  diffusion  and  digestion  of 
the  sewage  by  the  harbor  waters  is  here  especially  favorable. 

At  the  treatment  works  for  all  the  subdivisions,  grit  chambers,  with  a  settling 
period  of  from  one  to  two  minutes,  will  be  provided.  Where  screening  is  to  be  used,  the 
grit  chamber  will  prevent  heavy  deposits  which  might  occur  in  the  outlet  pipes  or  on 
the  harbor  bottom  near  the  points  of  discharge.  Where  settling  tanks  are  to  be  used, 
the  grit  chambers  will  guard  against  trouble  that  would  occur  from  the  deposition  of 
heavy  solids  in  the  tanks  which  are  intended  for  the  sedimentation  of  organic  matters. 

Sites  for  Treatment  Works.  Many  factors  have  affected  the  choice  of  sites  for 
treatment  works  in  the  various  subdivisions.  Among  the  chief  considerations  have  been 
the  existence  of  undeveloped  land  of  sufficient  area  for  plants  of  the  size  which  will 
ultimately  be  necessary,  the  location  of  these  areas  at  such  points  as  may  be  best  suited 
to  an  economical  collection  of  the  sewage,  this  collection  being  accomplished,  as  far  as 
possible,  without  the  use  of  pumping  machinery,  proximity  to  any  servicable  sewage 
outlets  that  might  occur,  and  favorable  location  with  respect  to  railroad  facilities. 

At  the  foot  of  Nautilus  street  there  is  ample  room  for  locating  a  screen  for  the 
Quarantine  subdivision. 

The  best  site  for  the  location  of  settling  tanks  for  the  Stapleton  subdivision  seems 
to  be  on  the  west  side  of  Front  street  between  Water  and  Prospect  streets.  This  loca- 
tion is  contiguous  to  the  railroad,  and  the  greater  part  of  the  site  is  occupied  by  an  old 
asphalt  plant  and  storage  yard,  which  is  out  of  use  and  for  sale.  On  the  Water  street 
front  there  are  a  few  old  tenements.  By  a  judicious  arrangement  of  tanks,  it  will  be 
possible  on  the  area  available  to  treat  all  the  sewage  that  is  likely  to  reach  this  point. 
If  for  any  reason  the  purchase  of  this  land  is  deemed  inadvisable,  there  are  other  unoc- 
cupied sites  in  the  immediate  neighborhood  which  probably  could  be  obtained. 

The  proposed  site  for  the  Livingston  treatment  works  is  west  of  Kissel  avenue  be- 
tween Richmond  terrace,  as  it  is  to  be  relocated,  and  Livingston  place.  There  may  be 
opposition  to  the  establishment  of  treatment  works  here,  but  it  is  the  logical  place  for 
them  and,  if  the  tanks  are  properly  operated,  no  offense  should  be  created. 

The  best  site  for  treatment  works  in  the  West  New  Brighton  subdivision  is  near 
the  garbage  incinerator.  Economy  of  operation  should  result  from  their  location  at 
this  point.  The  block  bouuded  by  Starin  avenue,  Dongan  street,  Richmond  terrace  and 
Bodine  street  seems  to  afford  the  best  site  for  the  works  and  has  therefore  been  selected. 
There  probably  will  be  plenty  of  room  within  this  area,  even  without  including  the  lots 


THE  RICHMOND  DIVISION 


87 


bordering  on  Richmond  terrace,  to  treat  any  volume  of  sewage  which  needs  to  be  col- 
lected at  this  point. 

In  the  Elm  Park  subdivision  the  most  favorable  site  seems  to  be  at  the  east  corner 
of  Richmond  terrace  and  Newark  avenue,  although  there  is  a  considerable  amount  of  un- 
occupied land  in  the  vicinity.  A  location  much  farther  to  the  west  would  be  inad- 
visable, if  for  no  other  reason  than  on  account  of  unfavorable  conditions  which  exist 
there  for  the  discharge  of  sewage. 

Capacities  of  Treatment  Works.  In  designing  the  treatment  works  sufficient  ca- 
pacity should  be  provided  to  take  care  of  the  volume  of  sewage  to  be  expected  for  a 
reasonable  period  in  the  future.  Nevertheless,  the  tank  capacity  to  be  provided  in  the 
first  installation  should  not  exceed  the  economical  limit,  as  units  can  be  added  when 
necessary. 

The  following  table  gives  the  estimated  average  daily  amount  of  sewage  which 
might  have  been  brought  to  the  various  works  had  they  been  in  existence  in  1910,  and 
also  the  capacities  which  were  used  as  a  basis  for  estimates  of  cost  of  construction  and 
operation  and  which  are  deemed  reasonable  as  capacities  to  be  provided  for  in  the  first 
installations. 


TABLE  XI 

Average  Sewage  Flow 


Subdivision 

Average  Sewage  Flow — Mgd.* 

Estimated  for 
1910 

Treatment  Wokrs, 
First  Installation 

Quarantine  

0.96 
2.26 
1.46 
2.06 
1.12 

3.0 
6.0 
4.0 
6.0 
3.0 

Livingston  

West  New  Brighton  

Elm  Park  

All  Sub-divisions  

7.86 

22.0 

*  Million  gallons  per  day  of  24  hours. 


Disposal  of  Sludge.  The  sludge  produced  in  this  division  may  be  disposed  of  in 
various  ways.  For  many  years  the  amount  of  sludge  will  be  comparatively  small.  In 
1910  the  digested  sludge  from  two-story  settling  tank  installations  in  the  four  subdivi- 
sions for  which  they  are  proposed  might  have  amounted  to  18  tons  a  day.  When  the 
capacities  of  the  first  tank  installations  are  reached  the  amount  of  sludge  will  prob- 
ably be  about  38  tons  a  day. 

The  treatment  works  in  the  district  are  so  placed  that  the  sludge  can  be  transported 
by  water  or  rail.  It  would  be  possible,  therefore,  to  dispose  of  it  either  at  sea  or  on 
land.  The  presence  of  two  garbage  incinerators,  both  almost  directly  on  railroad  lines, 
would  make  it  feasible  to  burn  the  sludge  and  garbage  together.  Centrifugal  dryers 
might  be  placed  at  each  disposal  plant  to  dry  the  sludge  before  transportation,  or  it 
might  be  more  economical  to  install  such  dryers  at  one  or  both  incinerators  and  trans- 
port the  larger  volume  of  wet  sludge  to  the  incinerators  in  proper  cars. 


88  PLANS  FOR  THE  PROTECTION  OF  THE  HARBOR 

There  is  a  large  amount  of  waste  land  along  the  railroad  line  in  the  northwestern 
part  of  the  island,  near  Arthur  Kill,  which  would  be  suitable  for  filling  with  the  dried 
sludge  from  the  settling  tanks.  If  the  sludge  were  transported  hither  without  previous 
drying  it  would  probably  be  necessary  to  establish  drying  beds  near  the  railroad  before 
the  sludge  could  be  made  available  for  filling  purposes. 

If  the  sludge  is  to  be  disposed  of  at  sea  it  would  be  advisable  to  collect  it  at  one 
or  two  points,  to  avoid  construction  of  piers  and  loss  of  time  in  the  operation  of  sludge 
steamers.  For  the  purposes  of  this  report,  it  has  been  assumed  that  all  the  sludge 
would  be  delivered  wet  into  tanks  located  at  the  Stapleton  treatment  works,  from 
which  tanks  a  sludge  discharge  pipe  would  run  out  on  the  municipal  pier.  By  this 
plan  no  new  piers  would  have  to  be  built  and  the  sludge  steamers  passing  out  of  the 
harbor  from  other  treatment  works  would  have  to  deviate  only  slightly  from  their  course 
to  serve  as  carriers  for  the  Staten  Island  sludge. 

Cost  op  Main  Drainage  Works 

The  estimated  cost  of  the  main  drainage  works  proposed  in  this  report,  not  being 
based  on  detail  designs,  are  necessarily  of  a  preliminary  nature. 

The  following  tables  give  a  concise  summary  of  the  estimated  cost  of  construction 
and  of  the  annual  charges  for  maintenance  and  operation.  The  costs  of  land  and  rights 
of  way  are  not  included. 


TABLE  XII 
Estimated  Cost  op  Construction 


Subdivision 

Sewers 

Pumping 
Stations 

Outfall 
Pipes 

Grit 
Chambers 

Treatment 
Works 

Total 
Without 
Engineering, 
etc. 

Engineering 
and 
Contin- 
gencies, 
15% 

Total 
Costs 

Quarantine  

$38,225* 
62,430f 
84,995 

164,305 
62,125 

$8,000 
10,000 
6,000 
12,000 
12,000 

$6,000 
3,000 
12,600 
17,400 
13,500 

$8,000J 

63,000 

42,000 

63,000 

31,500 

$60,225 
141,930 
148,095 
260,205 
121,125 

$9,035 
21,290 
22,215 
39,030 
18,170 

$69,260 
163,220 
170,310 
299,235 
139,295 

Livingston  

West  New  Brighton 
Elm  Park  

$3,500 
2,500 
3,500 
2,000 

Whole  District .... 

$412,080 

48,000 

52,500 

11,500 

207,500 

731,580 

109,740 

841,320 

TABLE  XIII 

Estimated  Annual  Charges 


Subdivision 

Maintenance  and 
Operation 

Fixed  Charges 

Total 

Quarantine  

$3,820 

$3,505 

$7,325 

5,127 

8,260 

13,387 

4,694 

8,618 

13,312 

7,584 

15,142 

22,726 

Elm  Park  

5,742 

7,048 

12,790 

Whole  District  

$26,967 

42,573 

69,540 

*  Including  Force  Mains.  t  Including  Siphons  X  Grit  and  Screen  Chamber. 


Plate  II 
The  Richmond  Division 


CHAPTER  V 


THE  JAMAICA  BAY  DIVISION 

Boundaries  of  the  Division 

The  territory  included  in  the  Jamaica  bay  division  lies  in  the  southeastern  part 
of  the  City  of  New  York. 

The  division  is  bounded  by  an  irregular  line  following  the  watershed  from  23d 
avenue  and  Gravesend  bay,  Borough  of  Brooklyn,  to  a  point  about  three-quarters  of 
a  mile  east  of  Prospect  Park,  thence  northeasterly  to  the  easterly  boundary  of  New 
York  City  near  Creedmoor,  thence  southerly  following  the  city  boundary  to  the  ocean. 
The  total  area  of  land  to  bulkhead  line  is  about  83.8  square  miles.  Of  this  area  about 
35.5  square  miles  lie  in  Brooklyn  and  48.3  in  Queens. 

General  Features  of  the  Division 

The  principal  topographical  features  of  this  division  include  a  natural  ridge, 
which  forms  the  northern  boundary  of  the  territory,  and  from  which  the  land  slopes 
gradually  to  low-lying  tidal  meadows;  the  large,  shallow  expanse  of  Jamaica  bay, 
studded  with  numerous  marshy  islands  and  hummocks,  intercepted  with  narrow, 
crooked  channels;  and,  finally,  a  protective  barrier  formed  by  the  low,  sandy  shore  of 
the  Rockaway  peninsula,  separating  the  bay  and  the  rest  of  the  division  from  the  open 
waters  of  the  Atlantic  ocean.  In  places,  the  low-lying  meadows  to  the  north  of  the 
bay  extend  for  over  two  miles.  Back  of  the  meadows  the  upland  begins  and  runs  in 
a  slightly  elevated  tract,  which  rises,  on  an  average,  four  or  five  feet  per  thousand, 
until  near  the  northern  boundary  of  the  division,  where  the  elevation  increases  more 
rapidly. 

The  Jamaica  bay  division  is  partly  built  up.  Parts  of  it  include  a  thickly  settled 
district  in  Brooklyn,  parts  consist  of  separated  country  villages,  parts  of  strictly  rural 
territory,  including  farms,  and  parts  of  large  stretches  of  unprofitable  salt  marshes. 
Finally,  there  are  some  largely  attended  day  summer  resorts. 

The  population  of  the  whole  territory  in  1910  was  about  366,000,  including  13,000 
residents  of  Brooklyn,  now  draining  to  Gravesend  bay,  which  it  is  proposed  to  include 
in  the  Jamaica  bay  system.  The  density  of  settlement,  as  shown  by  dividing  the  pop- 
ulation by  the  area,  gives  but  a  poor  idea  of  the  extent  to  which  the  division  is  settled, 
for  the  reason  that  there  are  large,  unpopulated  sections  and  some  rather  densely 
peopled  parts.   The  density  thus  divisionally  determined  varies  between  sixty  persons 


90  PLANS  FOR  THE  PROTECTION  OF  THE  HARBOR 

per  acre,  at  a  point  in  Brooklyn,  to  one  in  ten  acres  near  the  head  of  Jamaica  bay  in 
Queens. 

Probable  Future  of  Jamaica  Bay 

Coney  Island  and  Rockaway  Beach,  each  of  which  is  visited  by  hundreds  of  thou- 
sands of  visitors  on  a  summer  holiday,  are  in  this  division.  Parts  of  the  division  have 
increased  largely  in  population  during  recent  years  and  are  still  growing  rapidly 
under  the  fostering  operations  of  real-estate  operators. 

The  shores  of  the  bay  are  now  devoted  almost  exclusively  to  the  uses  of  a  transient 
summer  population  and  the  waters  to  sailing,  bathing  and  the  cultivation  of  shell-fish. 

The  shell-fish  interests  of  Jamaica  bay  are  extensive.  These  waters,  which  first 
became  famous  for  oyster  culture  about  fifty  years  ago,  are  now  much  used  for  growing 
oysters  and  hard  and  soft  shell  clams.  The  beds  are  located  on  the  bottom  and  sides 
of  the  natural  main  channels.  The  future  development  of  the  bay  will  make  shell- 
fish culture  unsafe  from  the  standpoint  of  disease. 

Unlike  the  cultivation  of  oysters  and  hard-shell  clams,  which  is  carried  on  by 
means  of  seed  brought  from  elsewhere,  the  muddy  shores  of  Jamaica  bay  afford  seem- 
ingly endless  supplies  of  soft-shell  clams.  These  clams  are  free  to  anyone  who  will 
gather  them.  Persons  may  be  seen  digging  soft  clams  in  practically  all  parts  of 
Jamaica  bay  during  low  tides. 

In  summer  hundreds  of  small  boats  ply  the  waters  on  Sundays  and  holidays  and 
the  water  front  in  those  parts  of  the  bay  which  are  most  easily  accessible  are  settled 
with  crowded  communities  which  live  in  tents  and  cottages  of  an  inexpensive  nature. 

The  future  of  this  division  is  uncertain,  although  there  is  a  definite  plan  for  the 
development  of  Jamaica  bay  for  commercial  purposes.  This  plan,  which  was  proposed 
by  a  special  body  created  for  the  purpose,  and  known  as  the  Jamaica  Bay  Improvement 
Commission,  involves  extensive  engineering  works.  It  is  proposed  to  construct  a  sub- 
stantial and  regular  shore  line,  deep,  wide  channels  for  ocean-going  vessels  and  har- 
bor approaches  for  the  entrance  at  Jamaica  inlet. 

It  is  also  proposed  to  construct  a  number  of  canals  on  the  northern  shore,  each 
about  300  or  400  feet  in  width  and  from  4,500  to  12,000  feet  long,  extending  back  into 
the  territory  at  places  where  natural  creeks  exist,  so  as  to  increase  the  water  front. 
The  object  of  this  development  is  to  increase  the  shipping  facilities  of  New  York  by 
providing  additional  wharves,  storehouses,  terminal  facilities  and  space  for  the 
handling  of  vessels.  At  the  present  time  no  business  of  this  kind  exists,  or  is  possible, 
in  Jamaica  bay,  owing  to  the  shallowness  of  the  water,  lack  of  railroad  facilities  and 
storehouse  accommodations. 


THE  JAMAICA  BAY  DIVISION  91 

As  to  the  future  of  the  beaches  known  as  Coney  Island  and  Rockaway,  it  seems 
likely  that  they  will  long  remain  pleasure  resorts,  in  spite  of  any  commercial  develop- 
ment which  will  occur  in  the  neighborhood.  The  situation  of  Coney  Island  makes  it 
comparatively  remote  from  the  shipping  centers  and  the  ocean  front  of  Rockaway 
Beach  renders  it,  to  a  considerable  extent,  independent  of  the  natural  resources  of 
Jamaica  bay  which  commercial  conditions  may  destroy. 

It  is  necessary  to  carefully  consider  how  the  waters  of  Jamaica  bay  are  now  used 
or  are  likely  to  be  used  in  future  in  order  to  determine  the  degree  of  thoroughness  with 
which  these  waters  are  to  be  protected  from  sewage  pollution.  If  the  waters  are  to  be 
kept  pure  enough  for  bathing,  boating  and  shell-fish  culture,  a  different  method  of 
dealing  with  the  sewage  disposal  problem  of  this  division  should  be  followed  than  if 
the  bay  is  to  be  devoted  to  commercial  purposes. 

From  a  careful  study  of  the  Jamaica  Bay  Improvement  Commission's  reports  it 
seems  improbable  that  the  waters  of  this  division  could  be  used  both  for  shipping  and 
the  other  purposes  to  which  they  are  now  put.  The  development  of  the  bay  for  com- 
merce would  seem  necessarily  to  exclude  its  use  for  pleasure;  and,  conversely,  if  the 
bay  is  to  be  maintained  for  purposes  of  recreation,  its  value  will  be  seriously  impaired 
by  the  developments  of  commerce.  So  far  as  the  Metropolitan  Sewerage  Commission 
can  foresee,  the  future  of  Jamaica  bay  will  lie  along  the  lines  proposed  by  the  Jamaica 
Bay  Improvement  Commission.  It  appears  that  an  agreement  to  develop  this  harbor 
for  shipping  has  been  entered  into  between  the  U.  S.  Government  and  the  City  of  New 
York ;  that  outline  plans  have  been  officially  adopted  and  money  appropriated  to  begin 
the  work. 

That  the  development  of  the  area  draining  to  Jamaica  bay  will  be  rapid  probably 
will  not  be  disputed.  The  chief  causes  for  this  are :  First,  the  improvements  recently 
made,  and  those  in  contemplation,  by  the  Long  Island  Railroad  Co.  and  by  the  Brook- 
lyn Rapid  Transit  Co. ;  and  secondly,  Jamaica  is  probably  destined  to  be  of  consider- 
able importance  as  the  local  focus  of  railroad  lines  to  all  parts  of  Long  Island — to  the 
west  by  the  Pennsylvania  tunnels  and  to  New  England  by  the  bridge  now  under  con- 
struction across  the  East  river  near  Hell  Gate.  Already  large  sums  of  money  have 
been  appropriated  for  improvements  in  this  vicinity. 

The  effect  of  this  development  will  be  felt  all  along  the  branch  of  the  main  line 
of  the  Long  Island  Railroad  which  extends  east  and  west  near  the  northern  limit  of 
the  Jamaica  bay  division.  The  rapid  transit  lines  and  the  southern  branches  of  the 
Long  Island  Railroad  will  afford  quick  transportation  from  nearly  all  points  in  the 
drainage  area  to  Brooklyn  and  Manhattan. 

The  projected  Jamaica  bay  improvement  already  mentioned  will  provide  econom- 


92  PLANS  FOR  THE  PROTECTION  OF  THE  HARBOR 

ical  entrance  for  coastwise  and  inland  shipping.  Building  material  can  be  delivered 
by  water  at  low  shipping  rates,  stimulating  improvements  on  large  areas  accessible 
to  the  water  front,  which  now  are  unoccupied  and  of  little  value. 

It  has  been  proposed  to  establish  a  barge  canal  terminal  in  Jamaica  bay.  The 
length  of  water  front  and  the  large  marginal  areas  available  cannot  be  found  elsewhere. 
The  trip  from  Norton  Point  to  Rockaway  Point  via  the  ocean  can  be  obviated  by  the 
construction  of  the  Gravesend  ship  canal,  which  is  understood  to  be  included  in  the 
project  for  this  section  of  Brooklyn  that  has  been  adopted  by  the  city  authorities. 

Probable  Future  Population  op  the  Division 

In  planning  for  the  main  drainage  of  this  division,  it  has  not  seemed  best  to  at- 
tempt to  anticipate  conditions  more  than  forty  or  fifty  years  in  advance  of  the  present 
time,  for  the  reason  that  conditions  may  arise  which  will  result  in  an  increase  or  shift- 
ing of  population  quite  different  from  any  that  can  now  be  foreseen.  A  material  varia- 
tion from  forecast  population  is  more  to  be  expected  in  the  thinly  populated  and  rap- 
idly improving  areas  than  in  those  where,  as  in  much  of  the  Brooklyn  area,  populations 
are  dense  and  the  conditions  which  affect  growth  are  well  established.  For  this  reason 
estimates  for  sewerage  have  been  based  upon  a  population  in  the  Brooklyn  portion  of 
this  division  as  forecasted  for  1960,  while  in  Queens  the  populations  are  forecasted 
for  1950. 

The  expected  populations  are,  for  the  area  lying  in 

Brooklyn   884,100 

Queens    531,600 

Total  population  planned  for  1,415,700 

General  Outline  op  the  Proposed  Plan 
An  outline  of  the  plan  which  is  being  worked  out  follows : 

The  sewage  is  to  be  collected  by  the  separate  system,  so  far  as  possible.  Where 
this  is  not  feasible  the  sewage  provided  for  is  confined  to  the  dry  weather  flow.  Allow- 
ance is  made  for  an  unavoidable  inflow  of  ground  water. 

Where  sewers  have  been  constructed  on  the  combined  plan,  it  is  proposed  to  inter- 
cept the  dry-weather  flow  and  provide  storm  water  overflows  above  the  points  of  inter- 
ception. In  this  way  a  certain  amount  of  house  sewage  mixed  with  storm  water  will 
pass  to  the  bay  during  storms,  but  the  amount  which  will  enter  in  this  way  will  be  so 
small  in  comparison  with  the  diluting  water  that  no  objectionable  conditions  are  to  be 
apprehended  from  this  cause. 

A  serious  consideration  is  the  street  filth  and  grit  which  will  be  carried  down  with 


THE  JAMAICA  BAY  DIVISION  93 

the  surface  water.  This  might  seriously  pollute  and  form  deposits  in  the  bay.  The  dis- 
solved organic  matter  will  be  taken  care  of  by  the  large  volume  of  water  with  which  it 
will  be  diluted,  but  the  floating  solids  and  grit  should  be  removed  by  screening  and  grit 
chambers  placed  near  the  outlets  of  the  more  important  storm  water  drains. 

The  projected  long  canals  mentioned  earlier  in  this  report  will  be  most  difficult  to 
maintain  in  an  unpolluted  condition.  There  will  be  but  little  flow  through  them  and 
practically  no  flushing  effect  from  the  tides.  These  long  canals  may  become  nuisances 
similar  to  Gowanus  canal  and  Newtown  creek,  unless  proper  measures  are  taken  to 
protect  them. 

The  entire  area  can  be  divided  into  two  subdivisions  termed  respectively  the  East- 
ern Jamaica  subdivision  and  the  Western  Jamaica  subdivision.  Each  will  have  a  dis- 
tinct system  of  collection  and  disposal. 

The  Western  Jamaica  subdivision  will  be  the  larger.  It  will  collect  the  sewage 
from  a  population  of  1,192,400  in  1960,  located  on  about  49  square  miles  lying  north 
of  Jamaica  bay  and  west  of  Cornell  creek  and  east  of  Ulmer  Park.  The  sewage  from 
this  territory  may  be  expected  to  amount  to  as  much  as  166  million  gallons  per  day  in 
1960.  It  will  be  delivered  to  a  pumping  station  to  be  located  near  Flatbush  avenue 
and  Avenue  X.  From  this  point  it  will  be  pumped  through  force  mains  to  Barren 
Island,  where  it  will  be  treated,  and  the  effluent  discharged  through  submerged  out- 
lets into  Rockaway  inlet.   For  outlet  island  alternative  project,  see  page  97. 

In  the  Eastern  Jamaica  subdivision  there  will  be  about  38  million  gallons  of  sew- 
age collected  daily  in  1950.  This  will  be  from  a  population  of  223,300  on  the  27.4 
square  miles  of  Queens,  which  lie  to  the  southeast  of  Cornell  creek.  This  Eastern 
Jamaica  subdivision  is  divided  into  two  separate  areas,  one  in  Queens  and  one  in  Nassau 
County,  which  borders  the  head  of  the  bay.  The  sewage  from  these  is  collected  sepa- 
rately but  carried  to  a  common  treatment  plant  on  Jo  Cos  marsh.  The  northerly  area 
is  expected  to  contribute  21.6  million  gallons  of  sewage  per  day  from  a  population  of 
111,800  distributed  over  19.6  square  miles  of  territory,  while  the  southerly  area,  com- 
prising Far  Rockaway  and  the  Rockaway  peninsula,  is  expected  to  contribute  16.5  mil- 
lion gallons  per  day  from  a  population  of  111,500  on  7.8  square  miles. 

From  the  northerly  area  the  sewage  will  be  brought  to  a  pumping  station  near  the 
Rockaway  turnpike  and  Springfield  road ;  and  on  the  southerly  area  collecting  sewers 
from  the  east  and  west  will  collect  the  sewage  to  a  pumping  station  near  Rockaway 
boulevard  and  Lucia  avenue,  Edgemere.  From  the  pumping  stations  the  entire 
volume  will  be  pumped  through  submerged  mains  to  a  plant  where  the  sewage  will  be 
treated  on  Jo  Cos  marsh.    The  effluent  will  be  discharged  into  Broad  channel. 

The  operation  of  the  treatment  works  to  be  located  at  Barren  Island  and  Jo  Cos 


94  PLANS  FOR  THE  PROTECTION  OF  THE  HARBOR 

marsh  will  be  restricted  to  house  sewage,  with  such  manufacturing  wastes  as  it  may  be 
found  best  to  admit  into  the  sewers. 

Western  Jamaica  Subdivision 

It  is  intended  that  the  intercepting  sewer  of  this  subdivision,  called  the  Flatlands- 
Jamaica  interceptor,  shall  start  with  a  diameter  of  5  feet  4  inches  in  the  Old  South 
road  north  of  the  present  Jamaica  Disposal  Works.  It  will  pass  under  the  sewer  from 
Jamaica  and  intercept  the  sewage  from  that  division. 

The  sewage  from  the  low-lying  area  to  the  south  will  be  collected  at  the  present 
disposal  works  for  Jamaica.  This  station  will  then  be  converted  into  a  pumping  plant, 
and  the  sewage  will  be  pumped  into  the  interceptor.  At  Panama  street  the  inter- 
cepting sewer  passes  under  the  Panama  street  sewers ;  then  under  the  Brooklyn  aque- 
duct, the  location  of  which  controls  the  elevation  of  the  interceptor.  At  the  borough 
line  and  Cozine  street  the  diameter  is  to  be  8'6".  The  sewage  collected  at  the  present 
East  New  York  disposal  plant  is  to  be  lifted  into  the  interceptor  in  Vandalia  avenue. 

Assuming  that  Fresh  creek  will  be  dredged  for  purposes  of  navigation,  it  will  be 
best  to  cross  under  the  creek  by  a  siphon  rather  than  carry  the  interceptor  by  a  long 
detour  around  the  head  of  the  proposed  basin. 

At  the  head  of  Paerdegat  basin,  as  well  as  at  Hendrix  street,  the  existing  storm 
drains  will  pass  over  without  interfering  with  the  flow  by  depressing  the  arch  of  the 
interceptor,  but  the  domestic  sewage  collected  at  this  point  will  have  to  be  pumped 
into  the  interceptor.  On  Avenue  T,  between  Ralph  street  and  Flatbush  avenue,  the 
diameter  is  to  be  14'4".    The  invert  is  to  be  about  16  feet  below  mean  tide  level. 

At  Avenue  V  and  11th  street,  Bensonhurst,  a  pumping  station  has  been  built  to 
pump  the  sewage  of  the  neighborhood  to  the  92d  street  outlet  near  the  Narrows.  The 
sewer  leading  to  this  outlet  eventually  will  be  too  small,  and  it  is  proposed  to  divert 
this  sewage  by  means  of  a  sewer,  called  the  Gravesend  interceptor,  to  the  east  when 
conditions  require  the  change.  The  sewers  will  increase  from  4'0"  to  7'3"  diameter, 
and  meet  the  interceptor  from  Jamaica  at  Flatbush  avenue.  The  present  Coney  Island 
sewage  disposal  plants  will  be  abandoned  or  utilized  as  pumping  stations,  delivering 
sewage  to  pumps  to  be  installed  at  Ocean  Parkway  near  Avenue  W.  The  sewage  deliv- 
ered to  the  pumps  at  the  present  Shellbauk  creek  plant  will  be  pumped  to  the  inter- 
ceptor. 

From  Avenue  T  the  sewage  will  flow  through  twin  sewers  about  10'3"  square  to 
the  main  pumping  station.  Here  centrifugal  pumps  of  capacity  to  lift  350  million  gal- 
lons per  day  35  feet  will  be  installed.    This  is  the  only  pumping  station  required  on 


THE  JAMAICA  BAY  DIVISION 


95 


the  line  of  the  interceptors.  Two  7'2"  force  mains  will  then  convey  the  sewage  to  the 
disposal  plant  at  Barren  Island.    (See  Plate  III.) 

Barren  Island  is  a  most  suitable  point  at  which  to  treat  and  dispose  of  the  sewage. 
The  sewage  will  be  carried  to  this  point  by  what  is  called  the  Barren  Island  force 
main.  The  area  of  land  here  is  ample ;  the  land  belongs  to  the  city ;  garbage  reduction 
works  are  already  located  there;  there  are  no  residences  in  the  vicinity  except  for 
the  workmen  employed  at  the  reduction  plant ;  the  land  is  of  suitable  elevation  and  be- 
lieved to  furnish,  below  the  surface  mud,  good  material  for  foundations ;  it  is  accessible 
for  transportation  by  water ;  on  the  south  it  forms  one  shore  of  Rockaway  inlet,  which, 
on  account  of  its  depth,  swift  currents  and  proximity  to  the  ocean,  furnishes  a  suitable 
body  of  water  into  which  to  discharge  the  effluent. 

The  degree  of  purification  that  will  be  required  is  not  known  at  this  time.  A  rough 
computation  indicates  that  if  all  the  sewage  which  would  naturally  drain  to  Jamaica 
bay  by  1960  were  thoroughly  diffused  therein  the  sewage  would,  under  ordinary  con- 
ditions, be  diluted  by  about  147  volumes  of  water  at  times  of  low  tide.  This  would  be 
about  six  to  seven  times  the  amount  of  theoretical  dilution  required  to  provide  suffi- 
cient oxygen  to  digest  the  organic  matter  during  the  summer  months,  the  most  unfa- 
vorable of  the  year. 

As  this  ideal  condition  cannot  be  relied  upon,  treatment  to  remove  the  grosser 
solids  and  a  certain  part  of  the  dissolved  impurities  must  ultimately  be  provided.  In 
order  to  show  approximately  the  cost  of  the  works  when  this  territory  shall  have  be- 
come occupied  to  the  extent  above  described,  it  is  assumed  that  the  sewage  will  then 
have  to  be  subjected  to  clarification  in  settling  tanks  and  further  treatment  by 
sprinkling  filters  and  settling  basins.  About  100  acres  of  land  will  be  ultimately  re- 
quired for  the  entire  plant. 

The  effluent  from  the  plant  will  flow  through  four  submerged  pipe  lines  and  dis- 
charge in  the  deep  water  of  Rockaway  inlet.  The  inoffensive  sludge  from  the  settling 
tanks  can  be  used  for  many  years  to  fill  in  marsh  lands  near  the  plant,  or,  if  preferred, 
it  can  be  dumped  at  sea. 

The  estimated  cost  of  construction  of  this  system  for  the  full  future  estimated  pop- 
ulation is: 


Interceptors 
Siphons  


75,450  lin.  ft.  $4,321,660 
1,150  "   "  77,600 


Pumping  stations. 

Force  mains  

Treatment  plant. 


5  755,600 
9,400  "  "  356,200 


4,623,100 


Outfall  pipes. 
Contingencies 


3,000  "  "  154,150 


15%  1,541,690 


Total  cost 


$11,830,000 


96  PLANS  FOR  THE  PROTECTION  OF  THE  HARBOR 

This  sum  need  not  all  be  expended  at  once,  but  those  portions  built  should  be  in 
accordance  with  the  complete  plan,  so  far  as  practicable.  The  construction  of  some 
parts  of  the  pumping  plants,  siphons,  treatment  plant  and  outlet  pipes  can  be  deferred 
for  many  years. 

The  area  now  draining  to  Paerdegat  and  the  26th  Ward  and  Jamaica  disposal 
plants  require  immediate  relief.  This  relief  will  probably  have  to  be  met  in  part  by 
temporary  measures.  It  is  desirable  that  plans  for  this  portion  of  the  interceptor  lead- 
ing to  Barren  Island  be  prepared  and  the  work  constructed  at  the  earliest  opportunity. 

Eastern  Jamaica  Subdivision 

The  northern  or  Springfield  collector  starts  at  the  intersection  of  the  Herrick 
Plank  road  and  Springfield  road  with  a  size  of  2'2"x3'3"  and  runs  southerly  through 
Springfield  to  the  Rockaway  turnpike,  where  the  diameter  is  4'6".  Here  there  will  be  a 
pumping  station  provided  with  centrifugal  pumps  of  sufficient  capacity  to  lift  40  mil- 
lion gallons  per  day  77  feet.  The  sewage  of  the  entire  subdistrict  will  thus  be  conveyed 
across  the  intervening  marshes  and  under  the  proposed  channel  for  navigation  to  the 
Jo  Cos  marsh  disposal  plant  through  a  force  main  33"  in  diameter,  called  the  Spring- 
field force  main.    (See  Plate  III.) 

The  Rockaway  collector  will  start  with  a  diameter  of  21"  near  Belle  harbor, 
where  it  will  receive  the  sewage  from  Rockaway  Park  and  the  west  from  a  pumping 
station  located  near  Fifth  and  Newport  avenues. 

Running  easterly  along  Rockaway  boulevard,  with  pumping  stations  at  Seaside, 
Hammels  and  Arverne,  it  will  reach,  with  a  diameter  of  45",  a  main  pumping  station  at 
Edgemere.  On  the  east,  sewage  collecting  at  the  present  Far  Rockaway  disposal  plant 
will  be  pumped  through  a  12"  cast-iron  force  main  to  Mott  avenue  and  Sheridan  boule- 
vard from  which  a  gravity  collector,  increasing  in  size  from  30  to  36  inches,  will  run  to 
the  Edgemere  pumping  station.  At  Channel  avenue  this  collector  receives,  from  a  12" 
force  main,  the  sewage  collecting  to  the  existing  ejector  station  near  Ocean  and  Chan- 
nel avenues. 

The  Edgemere  pumping  station  will  be  provided  with  centrifugal  pumps  of 
capacity  to  lift  30  million  gallons  per  day  40  feet.  The  sewage  of  the  entire  southern 
part  of  this  subdivision  will  thus  be  carried  by  a  30"  force  main  to  Jo  Cos  marsh, 
crossing  under  the  proposed  channel  for  navigation  on  the  way,  and  called  the  Rocka- 
way force  main. 

Jo  Cos  marsh  has  been  selected  as  a  suitable  location  for  treatment  works,  as  it 


THE  JAMAICA  BAY  DIVISION  97 

is  at  present  waste  land  and  centrally  located  with  reference  to  the  drainage  area.  It 
is  at  the  same  time  a  good  distance  from  improved  property.  Finally,  it  is  adjacent 
to  the  junction  of  Hassock  creek  and  Broad  channel,  which  provide  as  favorable  con- 
ditions for  dilution  as  are  to  be  had  at  the  upper  end  of  the  bay.  The  currents  de- 
pend largely,  however,  upon  the  wind.  The  oscillations  of  the  tide  are  not  sufficient 
to  dispose  of  a  large  volume  of  putrescible  sewage.  The  plan  provides  for  the  sewage 
to  be  given  thorough  treatment  by  settling  tanks,  sprinkling  filters  and  settling  basins. 
The  works  will  cover  about  30  acres  of  ground  by  1950. 

The  effluent  will  be  conveyed  by  two  outlet  pipes  42"  in  diameter,  one  to  Hassock 
creek  and  one  to  Broad  channel.  The  sludge  can  be  used  to  fill  marsh  lands  or  it  can 
be  dumped  at  sea. 

The  estimated  cost  of  construction  of  this  system  for  the  full  estimated  future  pop- 
ulation is  as  follows: 

Collectors                                                                   40,025  lin.  ft.  $511,000 

Pumping  stations                                                                    7  79,600 

Force  mains                                                                25,725  "  «  330,070 

Treatment  plant   1,061,340 

Outfall  pipes                                                                    3,300   "  "  90,000 

Contingencies                                                                    15%  310,990 

Total  cost   $2,383,000 

Much  of  the  cost  can  be  deferred  for  an  indefinite  time.  Such  portions  as  are 
necessary  to  care  for  the  sewage  of  Rockaway  and  Far  Kockaway  should  be  provided 
at  an  early  date.    (See  Plate  IV.) 

Summary 

Following  is  a  summary  of  the  more  important  data  concerning  the  proposed 
sewerage  of  the  Jamaica  bay  division : 

To  To 

Barren  Island  Jo  Cos  Marsh  Total 

Area  drained,  acres                                                                                 35,739  17,920  53,659 

Population  served                                                                               1,192,400*  223,300**  1,415,700 

Mean  volume  of  sewage — million  gallons  daily                                                166  38  204 

Cost  of  works,                                                                            $11,830,000  $2,383,000  $14,213,000 

Annual  charges  including  interest  at  4|%  and  sinking  fund  for  50  years       $964,643  $239,980  $1,204,623 
*  Estimated  for  year  1960. 
**        "       "      "  1950. 


Alternative  Project  for  Disposal  of  the  Sewage  of  the  Western  Jamaica  Sub- 
division at  Sea 

The  sewage  from  the  Western  Jamaica  Subdivision  may  be  carried  to  the  outlet 
island  in  connection  with  that  from  portions  of  the  Lower  East  River,  Hudson  and 
Bay  Division  (see  Chapter  VI,  page  134).    Omitting  the  sewage  from  Jamaica,  on 


98  PLANS  FOR  THE  PROTECTION  OF  THE  HARBOR 

account  of  its  distance  from  the  main  sewer,  the  cost  of  construction  would  amount  to 
|4,072,000,  the  annual  charges  for  maintenance  and  operation  $80,362  and  the  total 
annual  charges,  including  interest  and  sinking  fund,  $286,402.   See  Plate  V. 

The  interceptors  would  then  provide  for  122  million  gallons  of  sewage  that  might 
be  expected  from  a  population  of  884,000  persons  by  the  year  1960,  but  pumping  and 
treatment  plants  would  be  provided  only  for  the  47  million  gallons  per  day  that  might 
be  expected  in  the  early  future  from  this  territory. 

In  this  way  the  large  outlay  for  a  disposal  plant  on  Barren  Island,  the  Flatlands 
pumping  station  and  the  force  main  between  the  two,  amounting  to  over  $5,500,000  in 
the  project  outlined  above,  would  be  unnecessary. 


PLATE  111 


CiRAs/ESEND 


INTERCEPTOR 


Flatlands     —     Jama  i  c  a 


Barren  Island  Force:  Main 


§2 


fOHU.  MAIN 


t-t-1     Rtifif  tomniM 


HWM  IKTM 


1  m  «<u  h'<* 


m-umt   11  mi 


t     -      RALPH  AVI 


CtHTRM 

ROCMftWAV       PAHA  SlASIOt     —     "  HAMMIH  ARVIRNl 


ROCKAWAV 


BQULLVARD 

toocMtot—  Far 


COLLE  CTOR 


1 

I 

( 

% 

a 

5 

FORCI 

MAM 

Lucia  Avt  -I 

ITTll  8av 

JO  Cos  Marsh 

Marsh 

i 

tb 
in 

* 

IIS 
„  III 

i 

it 

:  a 

Rockawav    Force  Main 


Springfield     Force    Main         Springfield  Collector 


mliropolitah  StwiftAOt  commission 
or  NtW  YORK 

PROPOSED  SEWERAGE  PROJECT 

— FOR  THE  1 

JAMAICA  BAV  BIVISIOM 
PROFILE  OF  SEWERS  LEADING  TO 
TREATMENT  WORKS 


Plate  IV 
The  Jamaica  Bay  Division 


PROPOSED  SEWERAGE  PROJECT 

in     FOR  THE     ■  i« 

W  @0VII3M 
WITH  TREATMENT  WORKS 

—  ON  — 

Haircri  I  sialic!  and  Jo  Co'S  Marsh 


JAMAICA           (JAY         D>  iiOH 

TO     8AMIN  ISLAND 

'0  JO  Coi  MAHlN 

IDfAL 

TOTAt 

rnr*.  isso 

MM  m  *c  At* 

HID 

n,m 

U.flll 

u.rji 

I7.»i0 

i  ■.•  mat (0  Pirui  knot) 

*I.»H,W) 

«**  ini 

108.100 

1. HI, 400 

!(».  100 

■,(«•(,.  <        Km   <.*  um 

[  ,4 

'/< 

44 

IM 

in 

PLATE  V 


o        <  o 

z  <-> 

111 


MEIROPOUTAN  SEWERWE  COMM1S1QN 
Of  NEW  YORK 

PROPOSED  SEWERAGE  PROJECT 

FOR  THE 

JAMAICA  BAY  DIVISION 
PROFILE  OF  EASTERN  INTERCEPTOR 
Leading  to  submersed  tunnel  td  outlet  island 

DATED  JAN. (913 

Note:-Dcftvmis  MeanSeaLevzi 'afSanay  Hook 
•  Lxistinof  Sewers 

SCALES 


CHAPTER  VI 

LOWER  EAST  RIVER,  HUDSON  AND  BAY  DIVISION 

Briefly,  the  works  which  the  Commission's  studies  indicate  should  be  constructed 
to  protect  the  waters  of  the  Lower  East  river,  Hudson  and  Bay  Division  consist  of  in- 
tercepting sewers  to  collect  the  sewage,  screening  plants  to  remove  the  coarser  solids, 
and  submerged  outlets  to  discharge  the  effluent  into  the  main  tidal  channels  at 
a  distance  from  shore.  Should  this  form  of  treatment  prove  insufficient  for  the  Lower 
East  River  Section,  it  will  be  desirable  to  remove  a  large  part  of  the  sewage  tributary 
to  the  Lower  East  river  by  means  of  a  tunnel  discharging  at  an  artificial  island  at  sea 
about  three  miles  off  the  Coney  Island  shore.  If  the  sewage  is  to  be  carried  to  sea, 
Dortmund  tanks  should  be  constructed  upon  the  island  and  the  sewage  subjected  to 
sedimentation  for  a  period  of  about  two  hours.  After  this  short  and  inoffensive  treat- 
ment the  sewage  can  be  discharged  into  the  ocean  with  confidence  that  the  putrescible 
matters  will  be  promptly  rendered  inert. 

The  Commission's  studies  of  the  Lower  East  river  situation  have  been  examined 
critically  by  five  eminent  sanitary  experts  whose  reports  will  be  found  in  Part  III, 
Chap.  I,  page  155,  of  this  report. 

Boundaries  and  Topographical  Features 

The  territory  in  the  Lower  East  river,  Hudson  and  Bay  Division  lies  on  both  sides 
of  the  Lower  East  river,  the  west  side  of  Manhattan  and  the  east  side  of  Upper  New 
York  bay.  It  extends  from  the  extreme  northwestern  boundary  of  the  city  to  below 
the  Narrows. 

It  contains  the  largest  population,  and  the  most  densely  settled  sections  of  any  of 
the  four  divisions  into  which  the  Commission  has  divided  New  York  for  the  purpose 
of  planning  the  main  drainage  and  sewage  disposal  works  which  will  be  required. 
Within  it  lies  the  major  part  of  the  Boroughs  of  Manhattan  and  Brooklyn,  which 
were  separate  cities  until  1898. 

This  division  is  bounded  on  the  east  by  a  line  which  begins  at  Bensonhurst  on 
Gravesend  bay,  runs  in  an  irregular  course  northeasterly  to  Forest  Park,  in  the  Bor- 
ough of  Queens,  and  thence  northwesterly  to  the  East  river  near  the  mouth  of  the  Har- 
lem river.  All  of  that  part  of  Brooklyn  and  that  part  of  Queens  which  lie  to  the  west 
of  this  boundary  line  are  included  in  the  division.  Crossing  the  East  river  the  bound- 
ary enters  upon  Manhattan  Island  at  East  Eighty-second  Street,  proceeds  north- 
westerly to  Central  Park  West,  which  it  crosses  at  Ninety-first  Street,  and  thence  fol- 


100  PLANS  FOR  THE  PROTECTION  OF  THE  HARBOR 


lows  an  irregular  northerly  direction  along  the  height  of  land  to  the  Harlem  river  at 
Spuyten  Duyvil.  That  part  of  Manhattan,  which  lies  to  the  south  and  west  of  the 
boundary  so  described,  lies  in  this  division.  A  small  part  of  the  division  borders  on 
tbe  Hudson  between  Spuyten  Duyvil  and  Yonkers.  The  western  boundary  of  the  divi- 
sion is  formed  by  the  Hudson  river,  Upper  New  York  bay,  the  Narrows  and  a  part  of 
(iravesend  bay. 

In  the  northern  and  southern  parts  of  this  division  the  topography  is  favorable  to 
drainage,  but  there  are  large  areas  near  the  center  which  are  so  low  and  flat  that  the 
construction  of  sewers  with  sufficient  grades  to  insure  self-cleansing  velocities  and 
outfalls  so  situated  as  to  provide  for  a  free  discharge  at  all  stages  of  tide  is  impossible.* 

Made  Land.  Many  of  the  sewers  in  Manhattan  feel  the  effect  of  the  rising  and 
falling  tide  for  a  considerable  distance  from  the  shores,  in  some  instances,  for  over 
one  mile.  The  worst  cases  of  this  kiud  are  usually  ascribable  to  the  inadequate  filling 
of  low-lying  or  submerged  areas  such  as  the  beds  of  creeks  and  the  once  marshy  shores 
of  water  courses.  A  remarkably  regular  shore  line,  made  by  filling  in  Manhattan,  is 
shown  on  modern  maps. 

TABLE  XIV 


Acres  of  Filled  Land  in  this  Division 

Borough 

Acres 

1,140 
1,520 
460 

Brooklyn  

Queens  

Total  

3,120 

The  filling  has  been  largely,  but  not  entirely,  done  along  the  water  front.  From 
82nd  Street  on  the  Hudson  river,  southward,  to  the  Battery,  and  thence  northward 
along  the  Lower  East  river  to  33rd  Street,  Manhattan,  the  marginal  street  is  entirely 
on  made  land,  the  total  length  of  shore  so  recovered  being  ten  and  one-half  miles.  In 
many  instances  the  made  land  extends  some  blocks  back  from  the  river  front  and  in 
tbe  neighborhood  of  Canal  Street,  Manhattan,  it  runs  across  the  island,  a  distance  of 
nearly  two  miles. 

On  the  Brooklyn  shore,  the  made  land  extends  from  a  point  north  of  Newtown 
creek  to  near  45th  Street,  South  Brooklyn,  a  distance  of  eight  miles.  The  Brooklyn 
Navy  Yard  is  entirely  on  made  land.  A  large  area  in  (lie  neighborhood  of  Red  Hook 
and  Gowanus  canal,  Brooklyn,  has  been  reclaimed  by  filling. 

The  growth  of  made  land  has  been  gradual.  It  has  increased  with  the  increasing 
size  of  the  city.    The  chief  object  in  filling  in  the  low-lying  places  has  been  to  elim- 

*For  data  as  to  topography,  residence  and  business  sections,  approximate  land  values,  and  populations,  see 
Plate  IX,  following  page  138. 


LOWER  EAST  RIVER,  HUDSON  AND  BAY  DIVISION 


101 


inate  swamps  and  marshes  and  make  the  area  of  ground  available  for  trade  and  com- 
merce more  extensive  than  originally  existed.  At  the  same  time  the  filling  has  proved 
a  convenient  means  of  disposing  of  refuse. 

If  cellar  earth  and  other  suitable  refuse  material  were  utilized  in  filling  in  the 
swamps  and  meadow  lands  which  exist  in  the  outlying  parts  of  New  York  City,  the 
shore  lines  in  parts  of  the  harbor  estuaries  which  are  now  seriously  polluted  would 
soon  be  straightened  and  the  water  would  be  more  easily  kept  clean  than  under  the 
existing  circumstances. 

To  facilitate  the  filling  in  of  the  low-lying  shores,  the  Harbor  Line  Board,  com- 
posed of  engineer  officers  of  the  U.  S.  Army,  which  has  charge  of  maintaining  the 
navigable  channels  of  the  harbor,  has  established  lines  for  solid  filling.  These  lines 
extend  throughout  the  harbor  and  give  a  good  idea  of  the  plans  to  which  future  opera- 
tions of  filling  will  probably  conform. 

The  land  which  lies  in  this  division  at  elevations  within  twenty  feet  of  mean  sea 
level  includes  all  the  filled  land  and  also  some  additional  areas,  mostly  in  Brooklyn 
and  Long  Island  City.  A  broad  belt  runs  from  the  head  of  Newtown  creek  to  the  vicin- 
ity of  tbe  Brooklyn  Navy  Yard.  The  total  area  below  twenty  feet  elevation  in  this 
division  is  about  3.3  square  miles  in  Manhattan;  6.5  square  miles  in  Brooklyn  and  2.9 
square  miles  in  Long  Island  City.  Seventy-three  per  cent,  of  all  the  land  in  this  divi- 
sion is  of  more  than  twenty  feet  elevation  above  mean  tide.  In  Manhattan  the  high 
land  lies  for  the  most  part  near  the  center  of  the  island.  The  highest  point  is  some- 
what above  200  feet,  and  is  situated  north  of  Dyckman  Street.  There  is  no  point  above 
sixty  feet  elevation  further  south  than  33rd  Street. 

In  Brooklyn  the  land  which  lies  at  an  elevation  above  sixty  feet,  exists  chiefly  in 
the  eastern  part  of  the  division,  where  a  well  recognized  ridge  runs  in  a  northeasterly 
direction  from  the  vicinity  of  the  Narrows.  Elevations  of  100  feet  or  more  frequently 
occur  on  this  ridge. 

Tidal  Range.  The  difference  between  mean  sea  level  and  mean  high  water  is  one- 
half  the  mean  tidal  range  as  given  in  Table  XV. 


TABLE  XV 


Range  of  Tide  in  New  York  Harbor 


Mean 


Spring 


Lower  bay,  Sandy  Hook  

Narrows,  Fort  Hamilton  

Upper  bay,  Governor's  Island  

Hudson  river,  Spuyten  Duwil  

East  river,  Halletfs  Point  (Hell  Gate) 

East  river,  Throg's  Neck  

Harlem  river,  High  Bridge  

Kill  van  Kull,  Shooter's  Island  

Newark  bay,  Passaic  Light  

Passaic  river,  Newark  


4.7 
4.6 
4.4 

4  0 

5  5 
7.2 
6.0 
4.6 
4.7 
5  0 


5.6 
5.6 
5.3 
4.8 
6.6 
8.5 
7.2 
5.5 
5.7 
6.0 


102  PLANS  FOR  THE  PROTECTION  OF  THE  HARBOR 

Geology.  The  superficial  geological  formation  of  this  division  is  recent  except  for 
a  small,  low-lying  area  of  stratified  drift  in  and  near  125th  Street.  The  surface  of 
Manhattan  island  as  far  south  as  23rd  Street  is  composed  chiefly  of  mica  schist  rock. 
South  of  23rd  Street  the  rock  disappears,  and  stratified  drift  predominates. 

In  the  Brooklyn  part  of  this  division  drift  exists  on  each  side  of  the  central  ridge, 
the  ridge  itself  exhihiting  the  features  of  a  terminal  moraine  with  till  on  the  western 
slope.  Swamp  and  marsh  lands  exist  to  a  limited  extent,  and  then  only  in  that  part  of 
Queens  which  lies  in  this  division. 

Value  of  Land.  The  most  valuable  land  in  this  division  lies  in  the  central  and 
southern  parts  of  Manhattan.  It  is  a  peculiar  fact  that  whether  for  business  or  resi- 
dence purpose,  the  most  costly  land  lies  along  the  center  of  the  island.  At  the  southern 
extremity  is  the  financial  district.  North  of  this  is  the  City  Hall  with  the  central  post- 
office,  numerous  newspaper  offices,  the  principal  law  courts  and  municipal  administra- 
tive headquarters.  Next  above  follows  the  wholesale  dry  goods  center,  then  the  region 
of  retail  shops,  hotels  and  theaters  and  finally  areas  of  high-class  private  residences  and 
apartment  houses  which  extend  to  the  northern  limits  of  this  division.  From  this  cen- 
tral zone  east  and  west  to  the  river  fronts  lie  areas  occupied  by  factories  and  resi- 
dences, the  latter  ranging  from  modest  dwellings  to  congested  tenements. 

In  Brooklyn  the  water  front  is  chiefly  occupied  by  large  factories  and  warehouses. 
The  most  crowded  residence  district  and  the  center  of  financial  administrative  activity 
lies  in  that  part  of  the  borough  which  is  opposite  the  southern  end  of  Manhattan  Island. 

The  Existing  Sewers — Their  Outfalls  and  Resulting  Nuisances 

Practically  the  whole  of  this  division  is  sewered  on  the  combined  principle  of 
sewerage. 

In  addition  to  the  sewage  which  comes  from  the  storm  water  of  the  streets  and 
from  the  interior  of  the  houses,  the  sewers  of  Manhattan  and  Brooklyn  are  required  to 
carry  away  the  water  which  falls  upon  the  roofs,  yards  and  courts  of  the  buildings. 
The  connections  are  trapped  in  order  that  the  air  from  the  sewers  shall  not  enter  the 
houses.  The  plumbing  of  the  houses  is  ventilated  by  extending  the  soil  pipes  to  the 
roofs. 

In  many  cases,  especially  in  Manhattan  where  the  cellars  of  large  buildings  are 
deep,  it  is  often  necessary  to  pump  the  sewage  into  the  street  sewers.  This  is  done  at 
private  expense. 

Relief  Sewers.  In  most  of  Manhattan  the  sewers,  which  are  large  and  short, 
have  generally  proved  adequate  to  the  requirements  of  the  growing  population;  but 
in  Brooklyn  much  trouble  has  been  experienced  from  the  insufficient  provisions  which 


LOWER  EAST  RIVER,  HUDSON  AND  BAY  DIVISION  103 

were  early  made  for  drainage.  The  first  sewers  were  built  when  the  populations  which 
they  were  required  to  serve  were  small  and  scattered,  and  when  a  comprehensive  sys- 
tem of  sewers  was  built  between  1850  and  1860,  the  rainfall  data  were  inadequate  to 
permit  designers  fully  to  understand  the  requirements.  With  the  increasing  popula- 
tion the  original  sewers  have  been  supplemented  by  large  and  expensive  relief  sewers, 
and  these  in  turn  have  had  to  be  assisted  in  some  cases  by  the  construction  of  inter- 
cepting sewers  for  the  collection  and  removal  of  storm  water. 

The  sewers  of  Manhattan  and  Brooklyn  are  of  many  shapes  and  sizes.  Among  the 
older  sewers  of  Brooklyn  are  many  storm  drains  whose  courses  are  not  known.  The 
older  sewers  are  generally  circular  in  shape,  and  when  over  twenty-four  inches  in 
diameter  are  of  brick  or  concrete.  Clay  and  cement  pipe  have  been  extensively  used 
for  the  smaller  sizes.  Since  1907  the  principles  of  design  and  construction  have  been 
much  improved  in  Brooklyn. 

Most  of  the  sewer  outlets  on  the  Manhattan  shores  are  between  two  and  five  feet 
in  diameter,  but  there  are  some  which  have  a  section  equivalent  to  a  circle  having  a 
diameter  of  ten  feet  and  more.  The  outlets  on  the  Brooklyn  shore  are  somewhat  less 
numerous  and  some  are  larger  than  the  largest  of  Manhattan,  having  a  section  equal 
to  a  circle  with  a  diameter  of  fifteen  feet. 

Many  of  the  sewers  of  Manhattan  were  built  many  years  ago.  They  represent 
various  periods  of  growth  due  to  the  introduction  of  public  water  supplies  and  other 
causes  and  have  been  extensively  reconstructed  and  repaired  within  recent  years. 

Throughout  this  division  the  sewers  are  provided  with  catch  basins  at  the  street 
corners  which  were  intended  to  convey  the  storm  water  from  the  gutters  and  protect 
the  sewers  from  grit  and  other  solid  substances. 

Ventilation.  It  was  intended  that  the  sewers  throughout  this  division  should  be 
ventilated  through  perforations  in  the  manhole  covers  located  at  frequent  intervals 
in  the  street.  In  most  parts,  notably  in  the  older  sections  near  the  water  front,  the 
ventilation  is  defective,  partly  as  a  result  of  the  settlement  of  the  sewers,  the  entrance 
of  tide  water  and  the  submergence  of  the  outlets.  Nuisances  frequently  result  where 
steam  and  hot  water  are  discharged  into  the  sewers,  since  hot  vapors  rise  and  issue 
through  the  manhole  covers  disseminating  odors  of  cooked  sewage. 

Outlets.  The  outfalls  of  the  sewers  of  this  division,  as  elsewhere  in  the  metro- 
politan district,  are  located  at  the  bulkhead  or  shore  line  or,  frequently  in  Manhattan, 
near  the  outer  ends  of  the  docks  and  piers. 

The  submergence  of  the  sewer  outfalls,  as  at  present,  and  the  rising  of  the  tide 
drive  the  foul  air  into  the  streets  and  produce  coatings  of  grease  and  solids  upon  the 
sides  of  the  sewers,  and  this  interferes  with  the  flow  of  sewage.    So  much  deposit  is 


104  PLANS  FOR  THE  PROTECTION  OF  THE  HARBOR 

produced  in  some  of  the  sewers  that  a  cleaning  gang,  working  continuously,  can  make 
no  appreciable  reduction  in  the  depth  of  the  deposit.  Congealed  grease  has  been 
found  to  measure  as  much  as  a  foot  in  thickness  in  some  of  the  sewers  of  Manhattan. 

Physical  Condition.  Inspections  of  the  sewers  made  by  the  Metropolitan  Sewer- 
age Commission  with  the  co-operation  of  the  Bureau  of  Sewers  of  the  Borough  Pres- 
ident of  Manhattan  have  revealed  many  examples  of  distorted  shapes,  worn  out  in- 
verts, sunken  arches,  and  cracks  due  to  settlement,  In  many  places  irregular  holes 
had  been  broken  through  sewers  in  making  connections,  and  the  holes  never  properly 
repaired.  It  was  impossible  to  enter  some  of  the  sewers  for  inspection  owing  to  steam 
and  hot  water  escaping  from  neighboring  buildings.  Other  sewers  could  not  be  entered 
on  account  of  the  presence  of  illuminating  gas  in  such  quantities  as  to  endanger 
health.  In  other  areas,  lanterns  could  not  be  carried  into  the  sewers  on  account  of 
gasoline  vapor,  presumably  from  automobile  garages  or  other  establishments  using  this 
explosive  compound. 

In  Manhattan  the  sewers  are  inspected  and  cleaned  only  on  complaint.  The  sewers 
are  not  flushed,  but  are  cleaned  by  hand.  Street  sweepings  are  frequently  pushed  into 
the  catch  basins  against  orders  in  Manhattan  and  Brooklyn. 

Catch  Basins.  The  effect  of  the  catch  basins  in  removing  solids  from  the  sewage  is 
comparatively  slight.  They  soon  become  filled  with  grit  and  other  solid  matters.  To 
be  of  material  use,  they  should  be  cleaned  after  nearly  every  storm.  This  is  not  done. 
The  records  for  the  year  1909  show  an  average  of  one  cleaning  for  each  catch  basin  in 
Manhattan  every  5.3  months.  This  does  not  mean  that  all  the  6,348  catch  basins  in  the 
borough  were  cleaned.  Some  were  cleaned  out  at  comparatively  frequent  intervals 
and  others  were  not  cleaned  at  all. 

In  the  year  1907  the  catch  basins  in  Brooklyn  were  cleaned  on  an  average  about 
21//>  times  a  year  and  the  quantity  of  deposits  removed  aggregated  35,272  cu.  yds.  The 
cost  of  removing  this  material  was  |1.12  per  cubic  yard.  The  incompleteness  and 
great  cost  of  removing  solid  matter  from  sewage  by  the  use  of  catch  basins  can  be 
readily  understood  from  these  figures. 

Large  quantities  of  solid  matters  which  pass  the  catch  basins  are  deposited  in  the 
sewers  themselves  and  are  eventually  removed  by  hand,  washed  out  by  the  flood  water 
of  storms,  or  carried  away  through  the  alternate  choking  and  flushing  action  which  is 
produced  by  the  rising  and  falling  tide. 

About  400,000  cubic  yards  of  deposits  are  dredged  each  year  from  the  slips  and 
docks  of  that  part  of  Manhattan  which  lies  in  this  division  by  the  Department  of  Docks 
and  Ferries  and  large  quantities  are  also  dredged  by  private  enterprise  and  from  the 
Brooklyn  shores.    It  is  generally  conceded  that  this  solid  material  comes  chiefly  from 


LOWER  EAST  RIVER,  HUDSON  AND  BAY  DIVISION  105 

the  sewage.  The  water  from  which  the  deposits  are  taken  is  often  black  and  offensive 
and  gases  of  putrefaction  rise  in  innumerable  bubbles  from  the  deposits  at  the  bottom. 
During  flood  currents  the  sewage  matters  are  driven  back  into  the  slips  and  in  this 
quiet  water  some  of  the  solid  matters  are  deposited.  On  the  outgoing  tide  grease  and 
excreta  are  left  adhering  to  the  dock  walls  and  piers.  In  the  immediate  vicinity  of  the 
outfalls  the  water  is  discolored  and  objectionable  in  appearance  and  odor.  In  some 
cases  many  acres  are  rendered  turbid  by  the  sewage. 

Nuisances.'  Extensive  nuisances  occur  in  this  division  at  various  points  along  the 
Brooklyn  and  Manhattan  shores.  Gowanus  canal,  Wallabout  bay,  Newtown  creek,  the 
foot  of  Broad  Street,  Oliver  Street  and  Fourteenth  Street  are  the  most  conspicuous. 
The  bodies  of  water  affected  are  actually  large,  although  small  in  comparison  with  the 
great  areas  of  the  main  divisions  of  the  harbor.  The  condition  of  Gowanus  canal,  into 
which  a  15-foot  relief  sewer  as  well  as  some  eight  other  sewers  ranging  from  V/2  to  6 14 
feet  in  diameter  discharge,  has  been  notorious  for  years.  The  water  is  black  and  foul- 
smelling  at  all  times  and  the  sides  of  the  piers,  bulkheads  and  masonry  structures  are 
coated  with  deposits.  As  a  means  of  improving  this  canal,  the  Borough  of  Brooklyn 
has  constructed  a  flushing  tunnel  which  leads  from  the  head  of  the  canal  to  an  outlet 
in  the  Upper  bay.  Pumps  force  the  water  from  the  head  of  the  canal  through  the 
tunnel,  which  is  6,270  feet  long  and  12  feet  in  diameter.  The  outlet  is  about  2  feet 
below  low  tide  and  is  situated  close  to  the  shore  between  two  long  piers.  The  water 
in  the  vicinity  of  the  outlet  is  strongly  discolored  when  the  pumps  are  in  operation, 
the  discharge  from  the  tunnel  being  visible  at  times  in  the  water  after  it  has  been 
carried  by  the  tide  for  a  distance  of  more  than  a  mile. 

Wallabout  bay  in  the  Lower  East  river  is  polluted  by  a  9-foot  sewer  which  dis- 
charges at  the  bulkhead  line.  The  point  of  discharge  is  so  protected  from  the  tidal 
currents  that  a  satisfactory  dispersion  of  the  sewage  cannot  take  place.  The  bay  is 
exceedingly  offensive  at  all  stages  of  tide,  the  bottom  being  covered  with  putrefying 
sewage  sludge  and  the  top  with  sewage  apparently  in  an  undiluted  state.  These  ob- 
jectionable conditions  are  in  front  of  the  New  York  Navy  Yard. 

Newtown  creek,  which  empties  into  the  Lower  East  river  from  a  low-lying  manu- 
facturing district  north  of  Brooklyn,  is  an  offensive  body  of  water.  It  supports  a  heavy 
traffic.  Considerable  quantities  of  manufacturing  wastes  are  discharged  into  the  creek 
from  warehouses,  elevators  and  factories,  which  line  both  banks.  Some  sewage  empties 
into  it,  although  the  further  pollution  of  this  stream  is  prohibited  by  law.  A  15-foot 
sewer,  constructed  through  the  joint  action  of  the  Boroughs  of  Brooklyn  and  Queens, 
empties  into  the  head  of  Newtown  creek  and  although  this  sewer  was  intended  to  ac- 


106  PLANS  FOR  THE  PROTECTION  OF  THE  HARBOR 

commodate  storm  water  only,  the  dry-weather  flow  being  diverted,  considerable  pollu- 
tion is  ascribable  to  it. 

The  condition  of  the  waters  of  the  Lower  East  river  as  regards  oxygen  is  described 
in  this  report,  Part  IV,  Chap.  VI,  page  641,  and  Part  III,  Chap.  I,  page  184. 

There  are  no  figures  available  to  show  the  total  cost  of  the  sewers  which  exist  in 
this  division.  It  has  been  estimated  that  those  of  Manhattan  exceeded  $26,000,000, 
and  it  is  believed  that  those  of  Brooklyn  have  cost  about  an  equal  sum.  There  are 
about  522  miles  of  sewers  in  Manhattan  and  about  814  miles  of  sewers  in  Brooklyn. 

Possibility  That  the  Sewers  op  Manhattan  Will  Have  To  Be  Rebuilt. 

It  has  seemed  to  those  charged  with  the  duty  of  maintaining  the  sewers  of  Man- 
hattan, as  well  as  to  consulting  engineers  who  have  been  called  upon  to  examine  into 
the  subject,  that  it  would  eventually  be  necessary  to  reconstruct  a  large  part  of  the 
existing  sewers  of  Manhattan. 

The  chief  reason  for  reconstruction  lies  in  the  need  of  repairs  and  the  harm  done 
to  the  sewers  from  the  building  of  underground  structures  of  various  kinds,  as,  for 
example,  passenger  subways,  conduits  for  electric  light,  telephone  and  telegraph  and 
pipes  for  water,  gas,  steam  and  pneumatic  mail  service.  As  the  city  is  entering  upon 
extensive  subway  construction,  it  may  be  well  to  consider  whether  the  interferences 
which  now  exist  or  are  to  be  expected  will  not  cause  so  much  expense  and  make  the 
sanitar}7  removal  of  the  sewage  so  difficult  that  a  reconstruction  of  the  sewers  will  be 
a  practical  necessity.  If  the  sewers  are  to  be  rebuilt,  this  fact  should  be  known  and 
preparations  for  it  made  at  once  so  that  such  saving  as  can  be  effected  in  the  cost  of 
temporary  alterations  can  be  accomplished. 

Right  of  Way  of  Seicers.  Of  all  the  many  structures  beneath  the  city's  streets,  it 
is  most  important  that  the  sewers  should  have  the  right  of  way.  Unlike  pipes  for 
water,  gas  or  electricity,  which  operate  under  pressure,  sewers,  whose  flow  is  due  alone 
to  gravity,  must  be  laid  to  proper  grade  and  alignment  or  they  will  not  operate  properly. 

To  be  self-cleansing,  sewers  should  maintain  a  certain  velocity  of  flow  and  any  re- 
duction in  the  grade  which  checks  the  velocity  will  lead  to  deposits.  Short  turns  and 
bends  and  changes  in  the  cross-section  also  alter  the  flow  and  interfere  with  the  proper 
function  of  the  sewer. 

When  it  is  remembered  that  sewerage  systems  should  be  well  designed  and  con- 
structed; that  they  are  built  under  the  ground  in  a  manner  which  is  intended  to  be 
permanent  and  durable;  that  they  cannot  be  altered  in  size,  shape,  grade  or  location 
without  harmful  consequences;  that  their  function  is  to  carry  off  promptly  and  com- 
pletely the  most  offensive  and  dangerous  wastes  of  a  city,  the  claim  of  the  sewerage 


LOWER  EAST  RIVER,  HUDSON  AND  BAY  DIVISION 


107 


system  for  right  of  way  beneath  the  streets  appears  to  be  fully  justified.  That  this 
claim  has  not  been  respected  is  a  regrettable  fact.  In  defiance  of  the  officials  charged 
with  the  duty  of  maintaining  the  sewers,  they  have  been  moved  from  place  to  place, 
pierced  and  damaged  in  many  ways.  Instead  of  being  used  for  the  purposes  for  which 
they  were  built,  the  sewers  have  been  abused  by  the  discharge  into  them  of  harmful 
manufacturing  wastes,  hot  water  and  steam  and  been  rendered  dangerous  for  inspec- 
tion by  the  illegal  emptying  of  gasoline  and  other  inflammable  compounds. 

The  structures  which  interfere  with  the  sewers  are  located  at  depths  which  range 
from  that  of  the  shallow  conduits  which  carry  the  current  for  the  surface  railways  to 
that  of  the  passenger  subways.  The  passenger  subways  form  a  serious  obstruction. 
They  are  situated  as  close  to  the  surface  of  the  street  as  practicable  in  order  to  facil- 
itate entrance  and  exit  and  they  require  over  20  feet  of  depth.  For  the  most  part,  the 
subways,  like  the  water,  gas  and  other  large  mains  run  longitudinally  through  the 
island  and  the  sewers  in  seeking  their  outlets  to  the  rivers  run  perpendicularly  to  them. 

Interference  from  Subways.  The  first  subway  for  passengers  was  built  on  a  line 
which  divided  the  sewerage  systems  of  Manhattan  into  approximately  two  equal 
groups,  the  subway  following  along  the  axis  of  the  island  for  most  of  its  length.  The 
interference  with  the  sewers  was,  in  this  case,  as  slight  as  possible,  it  being  feasible  to 
cause  the  sewage  to  flow  in  many  instances  with  but  little  alteration  of  the  sewers  to 
a  convenient  point  of  discharge  to  one  of  the  nearby  rivers  on  the  east  or  west  side  of 
the  island.  But  other  subways  which  have  been  designed  will  mn  in  lines  nearly  par- 
allel to  the  first  and  will  divide  the  sewers  further.  There  will  be  no  easy  readjust- 
ment possible,  as  in  the  first  case,  for  there  will  be  a  central  area  which  will  be  blocked 
off  by  the  subways  from  the  river  on  either  side.  In  order  to  carry  the  sewage  past 
these  new  subways,  it  will  be  necessary  to  make  extensive  reconstructions.  It  will  be 
necessary  to  collect  the  sewage  to  more  or  less  suitable  points  in  the  areas  between  the 
subway  lines  and  then  conduct  it  by  siphons  beneath  the  subway  structure  to  points 
from  which  it  can  flow  away  by  gravity.  The  alignment  and  grade  of  the  sewers  will, 
in  many  cases,  be  seriously  interfered  with.  The  siphons,  which  should  be  capable  of 
being  emptied,  inspected,  repaired  and  cleaned,  will  be  costly  to  build  and,  when  of 
considerable  depth,  difficult  to  maintain.  Sewage  which  now  flows  directly  across  the 
island  will  have  to  be  diverted  so  as  to  run  for  considerable  distances  longitudinally, 
with  the  result  that  there  will  be  a  tendency  to  loss  of  velocity  and  formation  of 
deposits  in  the  drains. 

Need  of  Repairs.  An  important  argument  for  reconstructing  the  sewers  of  Man- 
hattan lies  in  the  need  for  repairs.  Inspections  made  by  the  Metropolitan  Sewerage 
Commission  have  shown  that  some  of  the  sewers,  and  especially  the  older  ones,  are  in 


108  PLANS  FOR  THE  PROTECTION  OF  THE  HARBOR 

dangerous  condition.  Of  246  inspections,  38,  or  one-sixth,  showed  places  where  the 
sewers  will  have  to  he  rehuilt  within  a  few  years  on  account  of  defective  hrick  work 
alone.  These  locations  exist  along  the  whole  length  of  the  island.  Of  the  522  miles  of 
existing  sewers  in  Manhattan,  55  miles  are  seriously  out  of  repair.  To  repair  these, 
would  involve  an  outlay  which  could  more  profitably  be  spent  on  new  construction. 

Separate  vs.  Combined  System.  If  the  sewers  were  reconstructed,  it  is  the  opinion 
of  many  engineers  that  they  should  be  built  upon  the  separate  system.  Drains  for 
storm  water  should  be  laid  close  to  the  surface  of  the  streets  and  should  be  large  and 
have  ample  grades  to  carry  off  much  solid  matter.  When  street  washing,  which  is 
rapidly  coming  into  favor,  becomes  general  in  the  city,  the  quantity  of  grit  and  other 
solids  to  be  removed  by  the  sewers  will  increase.  To  a  great  extent  the  storm  sewers 
should  be  made  to  carry  off  snow.  Storm  sewers  should  be  built  without  catch  basins 
at  the  street  corners  and  should  lead  to  central  points  where  grit  and  other  heavy 
materials  can  be  renuwed  before  the  sewage  is  discharged  into  the  harbor.  The  elim- 
ination of  the  14,000  catch  basins  which  now  exist  would  be  desirable. 

Sewers  for  house  drainage  should  be  laid  so  far  beneath  the  surface  of  the  streets 
as  to  permit  the  sewage  to  flow  into  them  by  gravity.  They  should  be  sufficiently  deep 
to  pass  clear  of  all  other  subterranean  structures.  The  comparatively  small  size  which 
the  sewers  for  house  sewage  would  require  would  permit  them  to  be  located,  even  in 
congested  streets,  so  as  to  give  good  alignment  and  grade.  The  sewage  would  thus  be 
more  promptly  carried  away  than  under  present  circumstances.  In  general  these 
sewers  would  run  perpendicular  to  the  subways,  crossing  under  them  and  delivering 
at  suitable  places  into  interceptors  for  conveyance  to  sewage  disposal  works  or  pump- 
ing stations. 

Objections  Against  Reconstruction.  The  objections  to  the  reconstruction  of  the 
sewers  of  Manhattan  lie  in  the  expense  and  inconvenience  which  the  reconstruction 
would  directly  and  indirectly  entail  upon  the  public.  Almost  all  the  streets  of  the  city 
would  require  to  be  opened  and  the  large  quantities  of  earth  and  materials  of  construc- 
tion would  have  to  be  handled  without  stopping  vehicular  traffic  where  the  alterations 
were  going  on.  The  plumbing  of  over  150,000  houses  would  require  to  be  altered  so 
that  the  proper  sewer  connections  could  be  made. 

It  is  not  clear  how  the  storm  water  sewers,  which  should  be  laid  close  beneath  the 
surface  of  the  streets  could  escape  the  underground  trolley  conduits  above,  and  the 
passenger  subways  beneath,  in  the  longitudinal  highways.  There  should  be  no  siphons 
on  these  storm  water  drains. 


LOWER  EAST  RIVER,  HUDSON  AND  BAY  DIVISION  109 

Quantity  and  Composition  of  the  Sewage 

The  quantity  of  the  sewage  produced  iu  this  division  can  be  estimated  from  a 
knowledge  of  the  water  consumed  and  the  rainfall.  But  few  of  the  sewers  have  been 
gauged  and  exact  measurements  of  their  flow  are  not  available.  As  compared  with 
many  cities,  especially  those  of  Europe,  the  volume  of  sewage  is  large  and  its  composi- 
tion variable.  It  is,  for  the  most  part,  remarkably  fresh  when  discharged,  owing  to  the 
short  distance,  and  consequently  brief  time,  consumed  in  passing  from  the  houses  to 
the  outfalls. 

The  conditions  of  residence  and  manufacture  are  various  in  this  division  and  the 
sewage  which  reaches  the  outfalls  is  correspondingly  variable.  The  quantity  pro- 
duced is  different  at  different  hours  of  the  day  and  night;  and  it  is  not  the  same  at 
all  seasons  of  year.  Owing  to  the  fact  that  most  of  the  sewers  for  some  distance  from 
the  shores  of  the  harbor  are  choked  with  tidal  water,  the  sewage  is  often  mixed  with 
salt  water  before  it  is  discharged.  In  some  cases  the  sewage  is  warm  with  the  waste 
steam  and  hot  water  which  is  discharged  from  large  office  buildings,  hotels  and  manu- 
facturing establishments. 

At  times  of  rain  much  polluting  water  is  washed  from  the  streets.  The  quantity 
of  this  material  is  doubtless  increasing,  due  to  the  more  extended  practice  of  washing 
the  streets  with  water.  After  snow  storms,  snow  is,  to  some  extent,  discharged  into 
the  sewers  and  with  it  more  or  less  solid  matter,  which  was  either  present  on  the  pave- 
ments before  the  beginning  of  the  storm  or  is  thrown  out  after  the  snow  begins  to  fall. 

For  the  composition  of  sewage,  and  for  the  quantities  of  sewage  materials  which 
are  tributary  to  the  various  divisions,  see  Part  IV,  Chap.  Ill,  page  499.  For  the  vol- 
umes of  sewage  tributary  to  the  various  divisions,  see  Part  II,  Chap.  II,  page  46. 

Possible  Methods  of  Sewage  Treatment 

Early  studies  made  by  this  Commission  indicated  that,  excluding  from  the  harbor 
as  much  sewage  matter  as  practicable  from  those  parts  of  Queens,  Richmond,  Brook- 
lyn and  the  Bronx  which  are  tributary  to  the  Upper  East  river  and  Upper  and  Lower 
New  York  bays  by  the  employment  of  local  purification  works,  the  water  of  the  inner 
harbor  would  be  able  to  assimilate  the  sewage  from  those  parts  of  Manhattan  and 
Brooklyn  which  were  closely  built  up  and  where  sites  could  not  readily  be  obtained 
for  the  construction  of  purification  works  of  high  efficiency.  In  this  belief  plans  were 
begun  for  collecting  the  sewage  of  the  Bronx,  Queens  and  Richmond  and  gathering  it 
to  a  number  of  conveniently  located  central  points  for  treatment. 

Two  immediate  objects  were  to  be  attained  by  these  plans.  First,  the  harbor 
water  in  those  divisions  where  the  works  were  located  was  to  be  kept  clean,  and,  second, 


110  PLANS  FOR  THE  PROTECTION  OF  THE  HARBOR 

the  water  was  to  be  protected  to  such  an  extent  as  to  insure  to  the  inner  harbor  the 
largest  assimilative  capacity  practicable. 

As  the  plans  progressed,  it  became  evident  that  a  high  degree  of  purification  could 
not  be  obtained  for  as  much  of  the  sewage  as  had  been  expected.  To  remove  a  large 
proportion  of  the  putrescible  material  from  sewage  requires  works  which  could  not 
always  be  situated  where  engineering  considerations  alone  would  have  placed  them. 
In  such  cases  land  must  be  procurable  at  a  price  which  does  not  unduly  increase  the 
first  cost  of  the  project.  Of  equal  importance,  it  is  necessary  to  locate  such  works  in 
positions  where  the  odors  produced  will  not  injure  property  to  such  an  extent  as  to  give 
owners  of  surrounding  land  valid  claims  against  the  city  for  damages. 

Odors  from  Efficient  Processes.  It  is  needless  to  deny  that  all  processes  of  sewage 
purification  cause  smells.  The  fact  should  plainly  be  faced  that  in  the  removal  the 
ingredients  of  sewage  which  are  capable  of  causing  the  water  into  which  the  sewage  is 
discharged  to  become  offensive,  objectionable  odors  may  be  produced  at  the  works.  The 
danger  of  nuisance  depends  partly  upon  the  degree  of  thoroughness  with  which  the  im- 
purities are  removed  and  partly  upon  the  likelihood  that  the  property  holders  in  the 
vicinity  will  find  the  odors  seriously  objectionable.  There  are  localities  in  the  City  of 
New  York  and  vicinity  where  objectionable  odors  are  continually  produced  by  manu- 
facturing establishments  with  little  or  no  complaint  from  property  holders.  But  these 
situations  are  not  usually  well  placed  for  sewage  disposal  plants,  and  it  is  doubtful 
if  the  city  would  be  justified  in  adding  to  these  odors  even  if  it  became  otherwise  desir- 
able to  construct  sewage  works  there.  Manufacturing  plants  which  are  objectionable, 
such  as  slaughter-houses,  bone-boiling  establishments  and  fertilizer  factories,  usually 
have  to  move  further  and  further  away,  as  the  cities  in  which  they  are  located  grow. 
Nuisances  of  this  kind  become  increasingly  objectionable  as  time  proceeds,  for  more 
and  more  people  become  affected  and  the  public  becomes  increasingly  fastidious. 

Such  strong  and  offensive  odors  as  are  produced  by  so-called  offensive  trades  are 
not  likely  to  be  produced  by  sewage  works,  but  the  difference  is  sometimes  not  great, 
and  the  erroneous  belief  that  sewage  odors  are  in  some  way  connected  with  disease, 
if  not  actually  a  cause  of  it,  adds  greatly  to  the  objectionableness  of  sewage  purifica- 
tion plants  in  any  locality. 

A  convenient  and  economical  location  for  sewage  works  is  hampered  by  the  un- 
certainty that  they  will  be  permanent.  Unlike  some  manufacturing  plants,  they  can- 
not well  be  moved  in  case  they  produce  a  nuisance.  If  they  are  objectionable  at 
first,  they  are  likely  to  become  more  so  with  the  passage  of  time.  Owing  to  the  pro- 
test with  which  a  proposal  to  build  a  municipal  plant  for  the  thorough  treatment  of 
sewage  probably  would  be  received  in  almost  any  part  of  New  York  City,  this  Com- 


LOWER  EAST  RIVER,  HUDSON  AND  BAY  DIVISION  111 

mission  has  felt  compelled  to  confine  its  plans  largely  to  works  of  the  simplest  char- 
acter or  carry  the  sewage  to  a  distant  point  for  disposal. 

In  the  selection  of  sites,  considerable  difficulty  has  been  experienced  because  of  the 
changing  character  of  many  localities.  Few  parts  of  New  York  are  permanently  con- 
structed. Solidly  built-up  sections  are  constantly  changing  from  residence  to  business 
occupancy.  Suburban  districts  are  rapidly  becoming  urban,  and  rural  territory  is 
being  converted  to  suburban  uses.  Each  change  increases  the  value  of  the  land.  The 
most  rapid  developments,  and  the  most  uncertain,  are  sometimes  in  the  very  localities 
where  it  would  be  most  convenient  to  build  sewage  disposal  works.  Here  unimproved 
property,  even  farm  land,  is  not  infrequently  held  at  a  high  valuation  in  the  expecta- 
tion that  a  strong  demand  for  real  estate  may  set  in  at  any  time. 

Owing  to  the  facts  here  mentioned,  this  Commission  has  not  found  it  feasible  to 
design  works  which  would  purify  the  sewage  tributary  from  the  outlying  territory  to 
a  high  degree,  and  the  water  which  will  reach  the  inner  harbor  will  consequently  not 
have  as  great  a  capacity  for  assimilating  sewage  as  theoretically  it  should  possess. 

What  is  here  said  as  to  the  nature  of  the  works  which  it  has  been  feasible  to 
design  for  Queens,  Richmond  and  the  Bronx  applies  with  greater  force  to  the  Lower 
East  River,  Hudson  and  Bay  Division.  The  aggregate  volume  of  sewage  produced  in 
this  division  is  now  great,  and  thirty  years  hence  will  be  about  double  what  it  is  to-day. 
Such  treatment  as  it  is  practicable  to  accomplish  within  the  territory  where  this  sew- 
age is  produced  will  remove  only  a  small  proportion  of  the  ingredients  which  are 
capable  of  reducing  the  amount  of  oxygen  in  the  water  into  which  the  effluent  is  dis- 
charged. Sprinkling  filters,  contact  beds,  sedimentation  basins  and  chemical  precipita- 
tion plants  cannot  be  considered  for  want  of  land  and  because  of  the  odors  which  such 
works  would  produce. 

The  forms  of  treatment  which  could  be  best  employed  on  the  shores  of  Manhattan 
and  Brooklyn  would  be  such  as  could  be  carried  on  with  grit  chambers  and  screens. 
The  report  of  Mr.  Datesman  (see  Part  III,  Chap.  I,  pages  259-263)  contains  a  discus- 
sion of  this  subject,  particularly  as  relates  to  sedimentation  basins  in  the  built-up  parts 
of  Manhattan  and  Brooklyn.  Beside  being  compact,  they  produce  little  odor;  they  can 
be  located  partly  below  ground;  they  require  no  extra  pumping;  they  are  compara- 
tively inexpensive  to  operate ;  they  can  be  employed  without  highly  skilful  supervision, 
and  it  is  practicable  to  have  many  plants  of  moderate  capacity.  Against  them  is  chiefly 
the  criticism  that  they  remove  only  the  largest  particles  of  sewage  matter  and  leave 
the  dissolved  organic  matter  and  finely  divided  putrescible  materials  to  pass  to  the 
harbor.  Notwithstanding  this  fact,  they  would  serve  usefully  in  attaining  the  standard 
of  cleanness  which  the  Metropolitan  Sewerage  Commission  has  proposed  for  the  water. 


112  PLANS  FOR  THE  PROTECTION  OF  THE  HARBOR 

able  for  treating  the  sewage  of  Manhattan  and  Brooklyn  locally,  it  is  desirable  to  con- 
Inasmuch  as  grit  chambers  and  screens  afford  the  best  practicable  means  avail- 
sider  how  such  works  would  be  constructed,  how  many  plants  would  be  required,  about 
where  they  should  be  built,  what  they  might  cost  and  how  much  improvement  they 
would  accomplish.  In  studying  these  questions,  two  chief  considerations  have  ap- 
peared to  be  important.  First,  the  outlets  from  the  works  should  be  so  built  that  the 
treated  sewage  will  be  promptly  and  thoroughly  diffused,  and  second,  the  plants  should 
be  so  located  as  to  permit  the  sewage  to  be  collected  to  them  without  unnecessary  diffi- 
culty or  expense. 

Submerged  Outfalls.  Owing  to  the  incompleteness  of  the  purification,  and  the 
desirability  of  complying  with  the  Standard  of  Cleanness,*  as  relates  to  discoloration 
and  turbidity,  it  would  be  necessary  to  discharge  the  effluent  from  the  plants  in  such 
a  way  as  to  produce  the  most  immediate  disappearance  of  the  sewage  which  is  pos- 
sible. For  this  purpose,  it  is  desirable  that  the  outfalls  should  be  near  or  upon  the 
bottom  and  be  so  located  that  ample  and  strong  currents  will  sweep  by  them. 

Locations  for  Outlets.  Bearing  in  mind  the  difficulties  of  construction  and  main- 
tenance, as  well  as  the  advantages  of  carefully  selected  places,  a  number  of  points 
have  been  chosen  along  the  shores  of  Manhattan  and  Brooklyn  where  the  sewage, 
after  treatment,  could  with  the  greatest  advantage  be  discharged. 

The  facility  with  which  the  sewage  could  be  collected  to  suitable  points  for  treat- 
ment was  taken  carefully  into  consideration  in  selecting  the  points  of  outfall.  It  was 
thought  desirable  that  the  sewage  should  require  the  least  amount  of  pumping  pos- 
sible; that  the  plants  should  not  have  to  be  placed  too  far  below  tide  level  and  that 
the  greatest  possible  normal  flow  of  sewage  should  be  gathered  to  each  plant. 

Considerable  care  has  been  taken  in  the  designs  to  make  an  economical  use  of 
land,  to  provide  for  adequate  inspection  and  repair,  not  only  of  the  apparatus,  but  of 
the  structure  itself,  to  insure  light  and  ventilation  and  to  facilitate  the  cleaning  of 
the  basins  and  screens  and  the  removal  of  the  impurities  from  the  plant.  Numerous 
forms  of  grit  chambers  have  been  designed  and  studied.  Every  form  of  screen  which 
the  experience  of  other  cities  had  proved  reliable  and  efficient  has  been  considered. 

Plan  Recommended  for  the  Disposal  of  the  Sewaoe  of  this  Division. 

Investigation  having  shown  that  it  will  be  impossible  permanently  to  discharge  all 
the  sewage  into  the  water  in  the  vicinity  of  the  territory  where  it  is  produced,  after 
such  purification  as  is  practicable,  it  becomes  necessary  to  consider  where  it  can  be 
taken  and  what  can  be  done  with  it. 

*Report  of  Metropolitan  Sewerage  Commission  of  New  York,  August,  1912,  page  70.  For  modification  of 
Standard,  see  Part  III,  Chapter  I,  page  218. 


LOWER  EAST  RIVER,  HUDSON  AND  BAY  DIVISION  113 

Amount  of  Sewage  to  be  Taken  Away.  It  will  not  be  worth  while  to  take  a  small 
amount  of  sewage  from  the  inner  harbor.  To  accomplish  much  benefit,  the  volume 
will  have  to  be  large  both  actually  and  in  relation  to  the  total  quantity  produced  in 
this  division.  If  possible,  it  should  be  taken  from  a  part  of  the  harbor  which  needs 
relief  both  on  its  own  account  and  because  of  its  influence  on  adjoining  sections.  As 
far  as  practicable,  the  sewage  should  be  collected  from  a  region  of  dense  population  in 
order  that  the  length  of  the  sewers  shall  be  no  greater  than  necessary.  For  the  same 
reason  the  distance  from  the  central  point  of  collection  to  the  point  of  disposal  should 
be  as  short  as  possible. 

This  report  shows  that  the  greatest  burden  of  pollution  which  is  placed  upon  any 
large  portion  of  the  harbor  is  discharged  from  Manhattan  and  Brooklyn  into  the 
Lower  East  river.  Here  within  a  distance  of  4  miles,  about  283,000,000  gallons  of 
sewage  are  discharged  every  24  hours  from  about  50  outlets  located  along  the  crowded 
shores.  Not  only  is  the  volume  of  sewage  large,  but,  as  shown  elsewhere  in  this  report, 
the  waters  are  peculiarly  unsuited  to  receive  it.  See  Part  IV,  Chap.  Ill,  page  496, 
and  Chap.  VI,  page  641. 

If  most  of  this  polluting  material  can  be  removed,  the  waters  in  the  immediate 
vicinity  will  be  improved  and  the  excessive  burden  of  pollution  now  put  upon  the 
whole  inner  harbor  will  be  relieved.  An  improvement  of  the  waters  of  the  Lower  East 
river  is  desirable  for  the  help  it  will  give  in  disposing  of  the  sewage  which,  in  accord- 
ance with  the  Commission's  plans  already  announced,  will  be  brought  to  Wards 
Island.*  At  Wards  Island  the  large  quantity  of  sewage  which  will  be  brought  from 
the  Harlem  river  will  be  passed  through  settling  tanks  and  discharged  into  the  deep 
waters  of  Hell  Gate,  and  reliance  must  be  placed  upon  the  digestive  capacity  of  the 
waters  to  oxidize  the  liquid  organic  matters. 

If  200,000,000  gallons  of  sewage  per  day  can  be  kept  out  of  the  Lower  East  river, 
the  ratio  of  sewage  to  water  in  that  section  will  improve  sufficiently  to  meet  all  re- 
quirements of  this  Commission's  standard  of  cleanness  for  the  present.  The  ratios  of 
water  to  sewage  which  will  exist  in  the  Lower  East  river  are  given  in  Table  XVI. 


TABLE  XVI 

Ratios  of  Sewage  to  Water  in  the  Lower  East  River,  if  200,000,000  Gallons  of 
Sewage  per  Day  are  Kept  out  of  This  Water. 


Year 

Sewage  to 
water  at  Low  Tide. 

Sewage  to 
Tidal  Prism. 

Sewage  to 
Net  Ebb  Flow. 

1910  

1  to  1090 
1  to  178 

1  to  204 
1  to  33 

1  to  30 
1  to  5.6 

1940  

•See  Chap.  Ill,  page  65. 


114  PLANS  FOR  THE  PROTECTION  OF  THE  HARBOR 

The  Plan  Recommended.  The  plan  recommended  by  the  Commission  contemplates 
the  collection  of  the  Manhattan  sewage  tributary  to  the  East  river  below  26th  Street 
at  Corlears  Hook,  and  that  part  of  the  sewage  of  Brooklyn  which  is  tributary  to  the 
East  river  from  Classon  Avenue  to  Newtown  Creek  at  South  5th  Street.  At  Corlears 
Hook  and  South  5th  Street  the  sewage  will  pass  through  grit  chambers  and  fine  screens 
and  will  be  discharged  into  the  East  river  through  multiple  submerged  outlets.  This 
is  the  first  stage  in  the  larger  project  of  taking  the  sewage  of  the  Lower  East  river 
section  directly  to  the  sea,  which  is  the  plan  the  Commission  recommends  for  ultimate 
construction. 

Advantages  of  Disposal  at  Sea.  In  accordance  with  the  ultimate  plan  proposed 
for  the  Lower  East  river  section,  the  sewage  will  be  tributary  to  a  general  central  sta- 
tion, to  which  point  will  be  gathered  such  part  of  the  sewage  as  needs  to  be  carried 
to  a  distance.  Pumps  will  be  located  at  the  central  station  and  from  it  a  main  will 
run  directly  to  an  outfall  island  to  be  built  about  3  miles  from  land  on  a  sandy  reef. 
This  reef  is  one  of  a  series  of  shallow  areas,  interspersed  with  channels,  which  once 
formed  the  bar  to  New  York  harbor.  It  lies  slightly  to  the  west  of  an  imaginary  line 
between  Sandy  Hook  and  Rockaway  Point.  The  outfall  will  be  about  13  miles  from 
the  New  York  City  Hall,  6  miles  from  the  Narrows,  over  4  miles  from  Sandy  Hook 
and  about  3  miles  from  Coney  Island.  The  point  selected  for  this  island  is  shown  in 
the  Frontispiece. 

As  much  sewage  as  it  is  necessary  to  carry  to  a  distance  from  the  Lower  East 
river,  Hudson  and  Bay  Division  can  be  taken  to  the  island  for  disposal.  As  time  pro- 
ceeds and  the  quantity  of  sewage  increases,  the  main  sewer  can  be  duplicated  and  the 
provisions  for  treating  and  discharging  the  sewage  at  the  island  can  be  enlarged. 

A  large  part  of  the  sewage  of  this  division  is  now  discharged  into  the  waters  of 
the  Lower  East  river.  If  this  sewage  is  taken  away  for  disposal,  it  will  for  some  time, 
at  least,  be  possible  to  discharge  the  sewage  from  the  rest  of  this  division  with  no  other 
treatment  than  screening  and  passage  through  grit  chambers.  The  water  of  the  Hud- 
son will  be  capable  of  assimilating  the  sewage  produced  on  the  west  side  of  Manhattan 
Island  and  the  water  of  the  Upper  bay  could  take  the  sewage  produced  along  the 
Brooklyn  water  front  from  Governor's  Island  southward. 

All  the  sewage  from  this  division,  except  that  part  which  is  taken  away,  should  be 
passed  through  grit  chambers  and  screens  and  the  dry- weather  flow  discharged  through 
submerged  outlets.  In  course  of  time,  if  the  quantity  of  sewage  from  this  division,  as 
well  as  from  that  part  of  the  Upper  East  river  and  Harlem  Division  which  would  be 
concentrated  at  Wards  Island,  increases  to  such  an  extent  as  again  to  place  an  exces- 
sive burden  upon  the  waters  of  the  East  river,  the  sewers  can  be  extended  and  finally 


LOWER  EAST  RIVER,  HUDSON  AND  BAY  DIVISION  115 

the  Wards  Island  works  can  be  connected  with  a  main  sewer  to  the  artificial  island 
for  disposal. 

The  plan  of  relieving  the  harbor  of  its  heaviest  burden  by  taking  to  sea  a  large 
part  of  the  sewage  which  flows  to  the  Lower  East  river  and  increasing  the  scope  and 
magnitude  of  the  work  as  necessity  arises,  appears  to  this  Commission  to  be  a  neces- 
sary and  sufficient  solution  of  the  problem.  In  no  other  way  can  the  sewage  be  dis- 
posed of  with  so  little  chance  of  danger  or  offense.  The  project  has  the  advantages 
that  it  will  afford,  at  minimum  expense,  all  the  relief  that  is  needed  for  the  near  future 
and  is  capable  of  expansion. 

There  are  no  shellfish  industries  in  the  vicinity  of  the  proposed  island  and  no 
currents  which  would  carry  any  of  the  sewage  to  a  bathing  beach.*  The  sewage  will 
not  be  exposed  long  enough  to  the  air  to  cause  annoying  odors  to  be  given  off  and  there 
will  be  no  opportunity  for  flies  to  breed. 

The  plan  is  in  accordance  with  the  best  engineering  precedent.  There  is  no 
feature  connected  with  it  which  is  untried  or  experimental.  It  avoids  offensive,  com- 
plicated and  uncertain  processes  of  purification.  It  is  based  upon  a  careful  considera- 
tion of  the  needs  of  the  whole  harbor.  It  leaves  the  waters  of  the  inner  harbor  in  a 
sufficiently  improved  condition  for  the  assimilation  of  such  sewage  as  cannot  be  kept 
out  of  the  waters  without  wellnigh  prohibitive  expense. 

Ultimate  Digestion  by  the  Sea  Water.  The  project  for  carrying  a  part  of  the  sew- 
age to  sea  contemplates  the  treatment  of  the  sewage  at  the  island  and  the  ultimate 
digestion  of  the  liquid  organic  matter  of  the  sewage  by  the  sea  water.  Responsibility 
for  the  disposal  of  the  sewage  cannot  cease  until  all  the  ingredients  are  rendered 
harmless  and  inert.  It  is  important  that  the  sewage  shall  not  flow  from  the  outlets 
as  a  coherent  mass  and  that  none  of  its  elements  shall  be  carried  to  the  inner  harbor 
or  find  their  way,  under  the  influence  of  wind  or  tide,  to  the  shore.  Accumulations  of 
solid  matter  injurious  to  navigation  must  not  be  permitted  to  occur,  nor  must  odors 
or  flies  or  other  objectionable  features  too  commonly  associated  with  sewage  disposal 
works  exist  to  mar  the  natural  attractiveness  and  healthfulness  of  that  part  of  the 
ocean  where  the  outlet  is  located. 

The  liquid  sewage  matter  will  have  a  strong  avidity  for  oxygen  and  will  be 
rendered  inert  by  the  oxygen-saturated  sea  water  with  which  it  comes  in  contact.  The 
great  amount  of  water  available  at  the  point  of  outfall  will  have  an  abundant  capacity 
to  digest  the  liquid  sewage. 

*For  numerous  long  range  float  observations  in  the  vicinity  of  the  island,  see  Part  IV,  Chapter  IV. 


116  PLANS  FOR  THE  PROTECTION  OF  THE  HARBOR 

At  first  the  form  of  treatment  needed  at  the  island  will  he  settlement  in  tanks,  per- 
haps aided,  at  times,  by  precipitants.  In  addition,  it  may  he  practicable  to  disinfect  the 
sewage  and  produce  a  considerable  amount  of  oxidation  by  the  addition  of  bleach  or 
electrolytically  produced  hypochlorite. 

If  at  any  time  in  the  future  it  becomes  desirable  to  completely  purify  the  sewage, 
no  such  favorable  location  for  the  necessary  works  can  be  found  in  the  metropolitan 
district  than  this  artificial  island.  Owing  to  the  shallowness  of  the  water  and  the 
ease  with  which  filling  can  be  obtained,  land  can  be  made  here  for  less  money  than  an 
equal  area  can  be  bought  on  shore  at  any  point  not  more  distant  from  the  New  York 
City  Hall.    (See  Figs.  31-35,  Part  IV,  Chap.  V,  pages  600-602.) 

In  addition  to  the  sewage  from  the  Lower  East  river  section,  it  will  ultimately  be 
feasible  and  desirable  to  send  the  sewage  of  the  western  Jamaica  bay  sub-division  to 
the  island  for  disposal.  This  would  make  it  unnecessary  to  construct  treatment  works 
at  Barren  Island,  as  proposed  in  an  earlier  report  of  this  Commission.* 

Collecting  the  Sewage  to  the  Outlet  Island 

Subdivision  of  the  Territory.  The  territory  included  in  the  Lower  Hudson,  Lower 
East  River  and  Bay  Division  has  been  separated  by  this  Commission  into  32  sub- 
divisions for  the  purpose  of  laying  out  the  works  which  will  be  necessary  for  the  sani- 
tary disposal  of  the  sewage,  and  each  subdivision  has  been  given  a  number.  The  sub- 
divisions numbered  1  to  12,  inclusive,  comprise  that  part  of  Manhattan  which  is  nat- 
urally tributary  to  the  Hudson  river.  Subdivisions  from  13  to  26  are  in  Manhattan, 
Queens  and  Brooklyn,  bordering  upon  the  Lower  East  river.  Subdivisions  27  to  31  are 
in  Brooklyn  and  border  on  the  Upper  bay.  Subdivision  32  borders  on  the  Narrows  and 
Gravesend  bay. 

The  subdivisions  vary  in  size  and  in  the  quantity  of  sewage  which  they  produce. 
The  boundaries  which  have  been  approximately  established  are  intended  to  show  the 
limits  within  which  it  will  be  feasible  to  collect  the  sewage  to  a  central  point  on  the 
water  front  in  each  subdivision.  The  central  points  are  usually  near  existing  large 
sewers  and,  as  often  as  practicable,  at  places  which  are  favorable  for  a  prompt  admix- 
ture of  the  sewage  effluent  with  the  harbor  water. 

As  stated  elsewhere  in  this  report,  the  dry-weather  flow  of  sewage,  after  collection 
to  a  central  point  in  most  of  the  subdivisions,  should  be  passed  through  grit  chambers 
and  screens  and  so  discharged  into  the  water  as  to  insure  prompt  diffusion. 

The  dry- weather  flow  of  sewage  produced  in  the  following  subdivisions  bordering 

*See  Chap.  V,  page  95. 


LOWER  EAST  RIVER,  HUDSON  AND  BAY  DIVISION  117 

upon  the  Lower  East  river  should  be  gathered  to  two  central  points,  passed  through 
grit  chambers  and  fine  screens,  and  discharged  at  the  bottom  of  the  deep  channels :  In 
Manhattan  13,  14  and  15,  and  in  Brooklyn  22,  23,  24  and  a  part  of  25. 

The  method  of  collection  in  those  subdivisions  from  which  the  sewage  is  eventually 
to  be  carried  to  a  distance  may  or  may  not  be  the  same  as  in  those  subdivisions  from 
which  the  sewage  will  be  discharged  into  the  neighboring  waters  as  a  permanent  pro- 
cedure. There  are  various  ways  in  which  the  sewage  can  be  collected.  The  Commis- 
sion has  spent  a  large  amount  of  time  in  the  study  of  this  subject,  and  is  of  the  opinion 
that  the  final  choice  should  rest  upon  surveys  and  plans  of  a  detailed  character.  One 
method  may  be  described  by  way  of  illustration.* 

The  dry-weather  flow  and  storm  water  equal  to  twice  the  dry-weather  flow  should 
be  provided  for.    The  excess  should  pass  by  storm  overflows  directly  to  the  river. 

The  Necessary  Interceptors.  In  designing  the  interceptors,  it  will  be  best  to  fol- 
low the  European  rather  than  the  American  practice.  According  to  the  American 
method,  the  interceptor  is  usually  constructed  entirely  below  the  invert  of  the  lateral 
sewer,  with  openings  connecting  the  two,  leaving  the  outer  end  of  the  lateral  open  for 
a  storm  overflow.  The  flow  into  the  interceptor  is  controlled  by  a  regulator,  which  is 
operated  by  a  float.  When  the  flow  in  the  lateral  reaches  a  certain  amount,  say  twice 
the  mean  dry-weather  flow,  the  regulator  closes,  cutting  off  the  entrance  to  the  inter- 
ceptor and  permitting  the  storm  flow  to  discharge  into  the  river  by  way  of  the  original 
outlet. 

According  to  European  practice,  the  interceptor  is  built  across  the  lateral  sewer, 
its  crown  above  the  invert  of  the  lateral.  The  interceptor  therefore  acts  as  a  dam,  pre- 
venting both  the  flow  of  sewage  to  the  river,  and  the  back  flow  of  the  tide  from  the 
river.  All  the  sewage  is  diverted  until  the  water  surface  in  the  lateral  rises  above  and 
overflows  the  crown  of  the  interceptor.  The  excess  storm  water  then  flows  directly  into 
the  river.  Where  the  crown  of  the  interceptor  is  too  high  to  permit  such  discharge,  a 
special  section  may  be  adopted  where  it  crosses  the  lateral. 

The  chief  advantages  of  this  arrangement  are:  The  elimination  of  mechanical  reg- 
ulators, which  are  not  always  reliable ;  a  raising  of  the  hydraulic  gradient  in  the  inter- 
ceptor and  consequent  reduction  of  lift  at  the  pumping  station ;  and  less  depth  and  con- 
sequently less  excavation  for  the  interceptors. 

The  interceptors  should  be  large  enough  to  accommodate  twice  the  mean  rate  of 
flow  during  periods  of  dry  weather.  The  maximum  rate  of  dry-weather  flow  is  as- 
sumed to  be  about  one  and  one-half  the  average  rate  per  24  hours.    This  will  permit 

*See  "Alternative  Projects,"  page  130. 


118  PLANS  FOR  THE  PROTECTION  OF  THE  HARBOR 

the  interceptor  to  carry  off  some  of  the  first  flush  of  storm  water  even  if  it  reaches  the 
plant  during  the  hour  of  maximum  sewage  production. 

The  intercepting  sewers  required  to  collect  the  sewage  from  the  present  sewers  to 
the  central  points  will  lie  as  close  to  the  surface  of  the  ground  as  physical  conditions 
permit.  In  making  the  plans  and  estimates,  careful  attention  has  been  given  to  the 
information  available  concerning  the  geology  of  the  territory  passed  through  as  deter- 
mined by  borings  made  by  the  Public  Service  Commission,  Board  of  Water  Supply 
and  others. 

The  Manhattan  Lower  East  Side  Subdivisions.  The  total  quantity  of  sewage  to 
be  taken  from  subdivisions  13,  14  and  15  is  estimated  at  99  million  gallons  per  24 
hours  in  the  year  1915.  The  estimated  popidation  for  the  same  year  is  680,500,  and  the 
area  from  which  the  dry- weather  flow  will  be  taken  is  1,737  acres. 

The  south  Manhattan  interceptor  will  start  near  the  foot  of  Broad  Street  with  a 
size  of  2  feet  6  inches,  increasing  to  a  diameter  of  4  feet  by  the  time  it  reaches  Roose- 
velt Street.  Here  there  will  be  a  lift  of  about  5  feet  by  pumps  and  the  interceptor  will 
continue  parallel  to  the  water  front  with  diameters  enlarging  from  5  feet  9  inches,  to 
8  feet  9  inches  at  East  Street,  Corlears  Hook.  The  north  interceptor  will  begin  with 
a  diameter  of  12  inches  at  26th  Street  and  flow  southerly,  enlarging  to  5  feet  6  inches 
at  14th  Street  where  there  will  be  a  lift  by  pumps  of  about  6  feet.  The  interceptor 
will  continue  south  with  diameters  increasing  from  10  feet  6  inches  to  10  feet  9  inches 
at  East  Street,  Corlears  Hook.  At  this  point  the  sewage  from  both  interceptors  will 
pass  through  a  grit  chamber  and  fine  screening  plant  and  will  then  be  pumped  to  tem- 
porary submerged  outlets  in  the  river. 

The  Inverted  Siphon  from  Manhattan  to  Brooklyn.  In  the  completed  installa- 
tion an  inverted  siphon  will  be  required  to  carry  the  sewage  from  Manhattan  to 
Brooklyn  beneath  the  Lower  East  river.  The  point  selected  for  the  crossing  is  at  a 
narrow  part  of  the  river  where  solid  rock  may  be  anticipated.  The  siphon  which  will 
be  required  to  take  the  sewage  produced  in  1915  will  have  a  diameter  of  7  feet  8  inches. 
The  depth  will  be  110  feet  beneath  the  surface  of  mean  low  water.  The  siphon  will 
be  2,400  feet  long  and  extend  from  Corlears  Hook  to  South  5th  Street.  The  velocities 
in  this  siphon  will  range  between  2  and  5  feet  per  second. 

The  Brooklyn  Northwestern  Subdivisions.  That  part  of  Brooklyn  which  is  in- 
cluded in  this  project  will  be  treated  in  a  way  similar  to  that  described  for  collecting 
the  sewage  from  the  Lower  East  side  of  Manhattan.  The  quantity  of  sewage  to  be 
taken  from  this  part  of  Brooklyn  will  be  a  little  larger  than  the  quantity  from  Man- 


LOWER  EAST  RIVER,  HUDSON  AND  BAY  DIVISION  119 

hattan  or  about  101  million  gallons  per  24  hours  in  1915.  The  estimated  tributary 
population  in  Brooklyn  will  be  larger  or  1,017,020  and  the  net  area  more  than  five 
times  as  large  or  8,866  acres. 

The  South  Brooklyn  interceptor  will  commence  at  Classon  Avenue  with  a  diam- 
eter of  10  feet,  taking  the  dry-weather  sewage  from  the  Classon  Avenue  sewer  and  in- 
creasing in  diameter  to  10  feet  8  inches  at  South  5th  Street.  The  north  interceptor 
will  start  at  Huron  Street  with  a  diameter  of  4  feet,  increasing  at  Quay  Street  to  9 
feet  10  inches,  and  reach  South  5th  Street  with  a  diameter  of  10  feet.  At  this  point 
the  combined  flow  will  pass  through  a  grit  chamber  and  fine  screens  before  discharge 
into  the  East  river  through  submerged  outlets.  In  both  Manhattan  and  Brooklyn  the 
interceptors  have  been  designed  of  sufficient  size  to  take  the  entire  tributary  flow  up 
to  the  year  1960. 

The  foregoing  represents  the  first  stage  of  development  recommended  for  the 
Lower  East  river  section.  In  the  completed  installation  the  Manhattan  sewage  (99 
mgd.)  brought  by  a  siphon  from  Corlears  Hook  will  join  the  101  mgd.  collected  from 
the  Brooklyn  side  at  South  5th  Street,  Brooklyn,  where  it  will  be  pumped  through 
three  6-foot  steel  force  mains  to  the  main  sewer  at  Wallabout  Street. 

From  this  point  it  will  be  carried  by  a  tunnel  12  feet  8  inches  in  diameter  under 
Brooklyn  and  New  York  Lower  Bay  to  the  proposed  outlet  island  about  three  miles 
off  the  Coney  Island  shore. 

Profiles  of  the  Manhattan  and  Brooklyn  interceptors  and  of  the  main  outfall  tun- 
nel are  shown  by  Plates  VI,  VII  and  VIII,  following  page  124. 

The  General  Pumping  Station.  The  sewage  collected  at  the  general  pumping 
station,  amounting  to  about  200,000,000  gallons  a  day,  will  have  been  passed  through 
grit  chambers  and  screens  and  will  be  in  reasonably  fresh  condition.  The  pumps  will 
be  required  to  raise  the  sewage  at  times  of  mean  flow  from  an  elevation  of  about  5 
feet  below  mean  tide  and  pump  it  under  a  head  of  about  29  feet  to  the  artificial  island 
at  sea.  The  distance  to  be  pumped  will  be  about  12.9  miles  and  the  head  to  be  over- 
come will  be  that  which  is  necessary  in  order  to  raise  the  sewage  from  the  level  at 
which  it  is  delivered  to  the  pumps  to  the  level  of  the  tanks  where  it  is  to  be  treated  on 
the  island,  plus  the  head  required  to  overcome  the  frictional  resistance  offered  to  the 
passage  of  the  sewage  through  the  long  main.  The  pumps  can  be  operated  by  steam, 
oil  or  by  purchased  electric  current.  It  would  seem  feasible  and  desirable  to  drive 
the  pumps  with  electric  power  to  be  obtained  from  burning  the  solid  refuse  of  the  city 
in  destructors,  as  is  commonly  done  in  England  and  in  certain  large  cities  of  Europe. 


120  PLANS  FOR  THE  PROTECTION  OF  THE  HARBOR 

The  Sewage  Main  to  Sea.  The  force  main  through  which  the  sewage  will  be 
pumped  to  the  island  will  be  built,  for  the  most  part,  in  tunnel.  There  will  be  three 
shafts,  so  situated  as  to  permit  the  work  of  construction  being  pushed  with  expedi- 
tion and  economy.  The  internal  diameter  of  the  completed  main  will  be  12  feet  8 
inches. 

The  estimates  given  below  are  based  upon  the  work  already  outlined,  but  since 
the  sewage  main  will  pass  comparatively  near  Jamaica  bay,  it  may  be  desirable  to 
modify  the  plan  which  this  Commission  proposed  for  the  Jamaica  Bay  Division*  to 
such  an  extent  as  to  permit  the  main  to  take  to  the  island  the  sewage  which  it  has 
been  proposed  to  collect  from  Brooklyn  to  Barren  Island  for  treatment  and  disposal. 
The  advantages  to  be  gained  by  this  change  are  (a)  reduction  in  cost  over  the  Barren 
Island  project  and  (b)  avoidance  of  the  necessity  of  constructing  a  sewage  disposal 
plant  at  the  entrance  of  Jamaica  bay.  By  adding  the  sewage  of  the  western  Jamaica 
bay  subdivision  to  the  sewage  of  Manhattan  and  Brooklyn  which  is  pumped  to  the 
island,  the  disposal  works  will  be  centralized  and  questions  of  administration  and 
maintenance  will  be  simplified. 

The  Western  Jamaica  Bay  Subdivision.  If  the  sewage  from  the  western  part  of 
the  Jamaica  Bay  Division  is  taken  to  the  proposed  island  for  discharge  at  sea  it  will  be 
collected  at  two  central  pumping  stations,  one  at  Hendrix  Street  and  the  other  at 
Flatlands  Avenue.  From  the  eastern  pumping  station,  an  interceptor  9  feet  to  9  feet 
6  inches  in  diameter  will  extend  for  2.6  miles  to  a  second  pumping  station  at  Flatlands 
Avenue.  From  this  point  the  interceptor,  enlarged  to  11  feet  4  inches  in  diameter,  then 
11  feet  8  inches  and  finally  to  12  feet  in  diameter,  will  extend  to  Nostrand,  where  it 
will  be  joined  by  a  small  interceptor  of  27  inches  from  the  present  sewage  disposal 
works  for  Sheepshead  bay,  which  will  be  converted  into  a  pumping  station.  The  inter- 
ceptor enlarged  to  12  feet  4  inches  will  end  at  a  pumping  station  to  be  located  at  Ocean 
Parkway  and  Avenue  W.  This  last  pumping  station  will  discharge  the  sewage  into 
the  main  which  runs  to  the  island. 

A  pumping  station  to  be  located  at  86th  Street  and  Avenue  V  in  Bensonhurst 
will  discharge  through  a  4-foot  interceptor  to  the  pumping  station  which  will  serve 
the  western  part  of  the  Jamaica  Bay  Division.  The  sewage  of  Coney  Island  will  be 
pumped  from  the  present  plant  known  as  Caisson  No.  3  directly  to  the  main  sewer. 

The  quantity  of  sewage  from  the  western  part  of  Jamaica  bay  will  be  about 
47,000,000  gallons  per  day  in  1915.  The  population  will  be  about  343,000  and  the 
area  served  19,000  acres. 

*See  Chap.  V,  page  97,  also  Plate  V,  following  page  98. 


LOWER  EAST  RIVER,  HUDSON  AND  BAY  DIVISION  121 

The  Artificial  Island.  The  tunnel  to  the  island,  if  sewage  from  the  Western 
Jamaica  Bay  Division  is  admitted,  will  be  14  feet  in  diameter  and  constructed  at  a 
depth  of  about  60  feet,  the  material  to  be  penetrated  being  sand.  It  will  be  possible  to 
construct  the  tunnel  with  two  headings,  one  from  the  shore  and  one  from  the  island, 
the  two  meeting  and  being  properly  joined. 

The  point  selected  for  the  island  has  been  carefully  chosen  with  reference  to  econ- 
omy of  construction,  resistance  to  the  destructive  influences  of  tidal  currents  and 
storms,  freedom  of  obstruction  to  the  free  flow  of  tidal  water  in  and  out  of  the  harbor 
and  absence  of  sanitary  objections. 

The  location  lies  to  the  north  of  Sandy  Hook  and  to  the  south  of  Coney  Island. 
Its  position  is  latitude  40  degrees  3iy2  minutes  and  longitude  73  degrees  58^2  min" 
utes.  The  water  within  a  mile  from  the  island  in  all  directions  varies  between  7  and 
40  feet  in  depth,  the  average  being  about  20  feet  at  mean  low  tide. 

The  plan  of  the  island  is  approximately  rectangular,  the  seaward  side  being 
rounded.  The  area  at  the  start  will  be  about  20  acres.  This  can  be  extended  as  re- 
quired.   The  general  plan  of  the  island  is  shown  on  Fig.  2,  page  122. 

The  outer  face  of  the  island  will  be  a  wall  of  riprap  composed  of  large  pieces 
of  broken  stone  carried  to  the  site  on  boats  and  laid  upon  the  hard  sandy  bottom  (see 
Figs.  2  and  3).  It  is  expected  that  some  settlement  will  occur,  due  to  the  water  cutting 
sand  away  from  under  the  stone.  When  sufficient  riprap  has  been  bedded  to  stop  this 
action  of  the  water,  no  more  settlement  is  to  be  expected.  The  main  bulk  of  the 
island  will  be  composed  of  sand  supplied  from  a  suction  dredge,  which  will  take  its 
supply  from  the  bottom  of  the  sea  in  the  vicinity. 

The  height  of  the  island  above  mean  low  water  will  be  about  18  feet.  The  length 
will  be  1,300  feet  and  the  width  1,000  feet.  The  side  of  the  riprap  wall  which  is  ex- 
posed to  the  sea  will  have  a  slope  of  1  vertical  upon  3  horizontal  below  mean  high 
water,  and  1  upon  2  above,  while  the  other  sides  will  have  a  slope  of  about  1  on  2. 
The  cost  of  constructing  the  island  has  been  estimated  at  about  $615,000. 

The  landward  side  of  the  island  will  be  provided  with  a  quay  wall  for  the  accom- 
modation of  vessels  engaged  in  taking  supplies  and  other  materials  to  and  from  the 
island.  Shelter  from  the  sea  will  be  provided  by  a  breakwater,  which  will  enclose  a 
small  harbor. 

The  island  will  contain  a  plant  of  settling  tanks  in  which  the  sewage  will  have  an 
opportunity  to  deposit  its  solid  matters  during  a  period  of  about  two  hours.  These 
tanks  will  be  of  modified  Dortmund  tank  construction,  similar  to  those  recently  con- 
structed at  Toronto,  Canada.  Provision  will  be  made  for  treating  the  sewage  if  neces- 
sary with  a  coagulant  before  passing  it  into  the  tanks. 


122 


PLANS  FOR  THE  PROTECTION  OP  THE  HARBOR 


OUTLET  CONNECTIONS 


.^'--Tnlet  well 


p 

supts.  house 

Llj  LANDING      '  IWfl, 

QUAY    WALL  BULKHLAD  WALL 


HARBOR 


Hi 


METROPOLITAN  SEWERAGE  COMMISSION 
OF  NCW  YOftft 

PLAN  OF  PROPOSED 

OUTLET  ISLAND 


— m  Scale,  of  FEET 
100        ZOO  300 


FIG.  2 


LOWER  EAST  RIVER,  HUDSON  AND  BAY  DIVISION 


123 


Section  on  A  a 


Section  on  bb 


METROPOLITAN  SEWEFtAGt  COMMISSION 
OF  NEW  YORK 


SEGTIONSofRETAINING  WALLS 

—  FOR  

OUTLET  ISLAND 


—  SCALE  or  FtET  — 
»     i     0  n  »  30         40  to 


FIG.  3 


124  PLANS  FOR  THE  PROTECTION  OF  THE  HARBOR 

After  treatment,  the  sewage  will  be  discharged  through  a  number  of  outlets  ar- 
ranged radially  on  the  seaward  side  of  the  island.  If  desirable,  it  will  be  feasible  to 
pump  sea  water  into  the  sewage  and  provide  for  the  mixture  of  the  two  before  the 
discharge  takes  place.  Such  admixture  would  facilitate  the  immediate  diffusion  of 
the  sewage  in  the  sea  water,  but  the  active  agitation  and  free  movement  of  the  great 
volume  of  water  in  the  vicinity  of  the  island  will  probably  make  the  preliminary  ad- 
mixture of  sea  water  and  sewage  by  pumping  unnecessary. 

The  material  which  settles  out  in  the  tanks  will  be  carried  to  sea  in  boats  and 
dumped. 

Cost.  This  project  will  require  the  construction  of  about  6.6  miles  of  intercept- 
ing sewers  in  Manhattan  and  Brooklyn.  The  siphon  from  Manhattan  to  Brooklyn 
will  be  a  little  less  than  a  half  mile  long.  The  main  from  the  pumping  station  to  the 
island  will  be  about  13  miles  long.  If  the  Jamaica  bay  sewage  is  brought  to  the 
island,  about  2  miles  of  collectors  and  7  miles  of  interceptors  will  be  required  in 
addition. 

For  the  first  installation  of  this  project,  the  estimated  cost  of  construction  is 
$4,095,000,  and  the  total  maintenance  and  fixed  charges  will  amount  to  about  $361,000 
per  year. 

For  the  entire  installation,  including  the  main  pumping  station,  outfall  tunnel, 
island  and  treatment  works,  the  total  cost  of  construction  would  be  about  $17,391,000, 
and  $4,072,000  additional  for  the  Jamaica  Bay  Division  if  included.  The  total  main- 
tenance and  fixed  charges  would  amount  to  about  $1,311,500,  with  $286,000  additional 
chargeable  to  the  Jamaica  Bay  Division. 

Recommendation  op  the  Commission  as  to  the  First  Installation 

In  the  opinion  of  the  Commission,  it  would  be  desirable  but  not  necessary  to  carry 
out  the  island  project  as  a  first  installation.  The  fine  screening  proposed,  although  the 
most  thorough  treatment  practicable  in  this  section,  would  afford  relief  to  the  Lower 
East  river  only  for  a  time.  The  improvement  effected  by  discharging  through  sub- 
merged outfalls  instead  of  at  the  pierhead  line  would  alleviate  conditions  in  the  slips 
and  along  the  shore,  but  would  not  make  the  water  permanently  satisfactory  nor  alter 
the  dilution  ratios  of  sewage  to  water  in  the  river  as  a  whole.  Any  benefit  accruing 
from  this  procedure  would  be  neutralized  later  by  the  increase  in  the  volume  of  sewage 
to  be  disposed  of. 

In  comparing  the  projects  for  local  sedimentation  treatment  as  considered  at  one 
time  by  the  Commission,  with  that  in  which  the  entire  200  mgd.*  is  taken  to  the  ocean, 

•Million  gallons  per  day. 


PLATE  VI 


-M                                                                         \  M 

l 

■ — H  

KUhhattah  V 
Scmtr  ' 

-to 

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T 

— 

Note.  -  The  Rocft  Sir  face  i*s  indicate*  "  locatea 
approximately  ■  ,■  but  is  3vi/ect 

"  to  rerision  ~ 


QBANODIORITt 


■fi 


EastRweqSiphon 
f  h)be  boilt  infuture)  jj-i.o 


Profiles  or  Proposed 

INTERCEPTING  SEWERS 

MANHATTAN 
PflOJtaXVHOttER  '■■■>■  RivtH  Huoion&BavDiv 

Scales  in  Feet 

Mortjonfat 
l  .  ,  .  _L_  

Vertical 


Existing  Sewer$ 

■*'    CR0SSED6rlHT£BCtPTiNGSE«R,  ElEV  NOT  KNOWN 

f   Flow  Intercepted  Elcv.Known 

!*:      •■  ■■  «  Elev.  Not  Knowm 


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i 


East  River  Siphon  [ 
(tobebuilnnrhe  future]  'J 


Profiles  of  Proposed 

Intercepting  Sewers 
Brooklyn 
Project  XVII- LowtREASTRivtB.HuDSOMftBAvD^ 

APR  W4 
SCAUE.5  IN  FttT 
Horizontal 

Vertical 


PLATE  VIII 


MnnoooiHAN  Tim w  Comnisjio* 
or  NiwYorh 

Project  XVM 

Profile  OFLAStRivf  b  Siphon.  Forc  i  Mains  &  MainSewi  fl 

FROM 


LOWER  EAST  RIVER,  HUDSON  AND  BAY  DIVISION  125 

it  must  be  remembered  that  by  the  former  project  the  tank  effluent  would  carry  to  the 
East  river  70  per  cent,  of  the  organic  matter  contained  in  the  sewage.  Now,  if  it  is  as- 
sumed, as  seems  fair,  that  but  25  per  cent,  of  the  total  organic  matter  capable  of  re- 
ducing the  dissolved  oxygen  of  the  harbor  is  removed  by  this  process,  it  follows  that, 
to  produce  an  improvement  of  the  water  equivalent  to  the  removal  of  200  mgd.  of  sew- 
age to  the  ocean,  it  would  be  necessary  to  treat  800  mgd.  by  screening.  This  is  more 
sewage  than  will  be  produced  in  the  whole  city  in  1915. 

In  other  words,  if  all  the  sewage  of  Greater  New  York  were  treated  by  fine  screen- 
ing, it  would  not  improve  the  general  condition  of  waters  of  the  harbor  as  much  as  the 
entire  removal  of  the  200  mgd. 

Opinion  of  U.  S.  Engineers  on  the  Proposed  Island 

Recognizing  that  responsibility  for  the  maintenance  of  a  proper  depth  of  water 
for  navigation  in  the  harbor  rested  with  the  TJ.  S.  War  Department  and  that  the  island 
proposed  by  the  Commission  for  the  disposal  of  the  sewage  of  the  Lower  East  river 
could  be  constructed  only  with  the  permission  of  that  Department,  application  was 
made  to  the  Secretary  of  War  requesting  the  views  of  the  War  Department  with 
respect  to  this  subject.  The  Commission's  application  was  referred  by  the  Secretary  of 
War  to  the  Chief  of  Engineers,  U.  S.  Army,  and  by  him  to  the  New  York  Harbor  Line 
Board  for  report. 

The  New  York  Harbor  Line  Board  consisted  of  Colonels  W.  T.  Rossell,  W.  M. 
Black  and  S.  W.  Roessler  of  the  Corps  of  Engineers,  U.  S.  Army.  The  island  would  be 
in  that  part  of  the  harbor  which  is  under  the  special  jurisdiction  of  Col.  Roessler,  who 
has  had  much  experience  with  breakwaters  and  other  structures  intended  to  resist  the 
destructive  action  of  the  sea.  The  Harbor  Line  Board  gave  a  hearing  on  the  Commis- 
sion's project  on  March  7,  1913.  On  that  occasion  the  subject  was  thoroughly  dis- 
cussed, plans,  charts  and  profiles  of  the  proposed  structures  being  produced. 

The  opinion  of  the  Harbor  Line  Boarrl  was  transmitted  to  the  Commission  by  the 
War  Department  on  March  22,  1913.  It  was  to  the  effect  that  an  island  in  either  of 
the  two  locations  suggested  by  the  Commission,  one  of  which  is  shown  on  Plate  I,  fol- 
lowing page  48  of  Preliminary  Report  VI  of  the  Metropolitan  Sewerage  Commission, 
would  not  interfere  unduly  with  navigation  nor  have  an  unfavorable  effect  upon  the 
harbor.    In  this  opinion  the  Chief  of  Engineers  concurred. 

The  correspondence  in  full  follows: 


126 


PLANS  FOR  THE  PROTECTION  OF  THE  HARBOR 


February  18,  1913. 

Hon.  Henry  L.  Stimson, 
Secretary  of  War, 

Washington,  D.  C. 

Sir:  In  making  plans  for  a  sanitary  disposal  of  the  sewage  of  New  York  City,  it 
has  become  desirable  to  consider  the  practicability  of  constructing  an  island  near  the 
entrance  of  New  York  harbor.  The  island  would  be  located  on  one  of  the  shallow, 
sandy  bars  which  are  divided  by  the  Fourteen  Foot  Channel  to  the  north  of  Ambrose 
Channel. 

The  island  would  be  constructed  with  an  enclosing  wall  of  riprap  and  a  filling  of 
fcand  or  other  solid  material,  the  total  area  occupied  being  less  than  30  acres.  Upon 
the  island  would  be  tanks  and  other  structures  in  which  much  of  the  solid  matters  of 
the  sewage  would  be  removed  to  be  carried  to  sea  in  boats  or  disposed  of  in  some  other 
acceptable  manner,  while  the  clarified  effluent  would  be  discharged  into  the  surround- 
ing water  through  outlets  so  arranged  as  to  insure  its  prompt  dispersion  and  disap- 
pearance. The  sewage,  amounting  to  about  200,000,000  gallons  per  twenty-four  hours, 
would  be  brought  to  the  island  through  a  tunnel. 

Recognizing  the  authority  which  is  exercised  by  the  general  government  over  the 
navigable  waters,  this  Commission  desires  to  place  its  project  in  sufficient  detail  before 
you,  to  the  end  that  an  early  determination  may  be  reached  as  to  the  permissibility  of 
constructing  and  using  this  island  in  the  manner,  and  for  the  purpose,  stated. 

Members  of  this  Commission  will  be  pleased  to  call  upon  you  with  reference  to  the 
subject  in  case  you  visit  New  York,  or  they  will  go  to  Washington  to  see  you,  if  prefer- 
able. The  technical  details  of  this  plan  can  be  laid  before  such  army  engineer,  officer 
or  officers  of  the  New  York  Harbor  Line  Board  as  you  may  designate. 

Your  early  attention  to  this  subject  is  requested  in  order  that  the  result  of  your 
consideration  may  be  known  in  time  to  be  used  in  a  report  soon  to  be  issued  by  this 
Commission. 

Respectfully, 

George  A.  Soper, 
James  H.  Fuertes, 
H.  deB.  Parsons, 
Charles  Sooysmith, 
Lin  sly  R.  Williams,. 


-Commissioners. 


March  3,  1913. 

Mr.  George  A.  Soper,  President, 

Metropolitan  Sewerage  Commission, 

17  Battery  Place,  New  York  City. 
Dear  Sir  :  1.  The  Harbor  Line  Board  has  before  it  your  application  of  Feb.  18  to 
the  Secretary  of  War  concerning  the  construction  of  an  artificial  island  near  the  en- 
trance to  New  York  harbor,  and  also  a  letter  of  Feb.  19th  from  Mr.  H.  deB.  Parsons, 
Consulting  Engineer,  requesting  that  this  matter  be  laid  before  this  Board.  In  order 
that  the  Board  may  be  able  to  come  to  a  definite  conclusion  in  the  case,  it  is  requested 
that  you  submit  more  detailed  plans  and  make  a  definite  application  for  such  con- 
struction. 


LOWER  EAST  RIVER,  HUDSON  AND  BAY  DIVISION 


127 


2.  The  Board  desires  to  take  this  matter  up  at  10  a.  m.  on  March  7th  and  it  is 
requested  that  these  plans  be  submitted  before  this  time  and  that  if  possible  you  or 
your  representatives  be  present  to  confer  with  the  Board  in  the  matter  on  that  date. 

Very  respectfully, 

William  T.  Rossell, 

Colonel,  Corps  of  Engineers, 
Senior  Member  of  Board. 

March  6,  1913. 

Colonel  William  T.  Rossell, 

Corps  of  Engineers,  New  York  Harbor  Line  Board, 
Army  Building,  New  York  City. 

Dear  Sir:  Your  letter  of  March  3,  relating  to  the  proposal  of  this  Commission  to 
construct  an  island  near  the  mouth  of  New  York  harbor,  has  been  received. 

Application  is  hereby  made  for  permission  to  construct  and  maintain  an  island 
for  the  treatment  and  disposal  of  sewage  in  accordance  with  the  following  plan : 

The  object  of  constructing  the  island  is  to  afford  opportunity  for  the  treatment 
and  final  disposition  of  a  quantity  of  sewage  from  the  inner  harbor  sufficient  to  relieve 
and  protect  the  inner  harbor  from  its  excessive  burden  of  pollution. 

The  location  proposed  for  the  island  is  in  shoal  water,  preferably  in  latitude 
40°  32'  02"  N,  longitude  73°  59'  46"  W,  or  in  latitude  40°  31'  26"  N,  longitude 
73°  58'  21"  W. 

In  plan,  the  island  would  be  approximately  rectangular  except  that  the  seaward 
side  would  be  rounded.  The  area  at  the  start  would  be  about  20  acres  of  filled  land 
and  about  10  acres  of  harbor  for  the  protection  of  vessels  engaged  in  transporting  sup- 
plies to  the  island  and  taking  sludge  and  other  materials  away. 

The  outer  face  of  the  island  will  be  a  wall  of  riprap  composed  of  large  pieces  of 
broken  stone  carried  to  the  site  on  boats  and  laid  upon  the  hard  sandy  bottom.  It  is 
expected  that  some  settlement  will  at  first  occur,  due  to  the  water  cutting  sand  away 
from  under  the  stone.  The  main  bulk  of  the  island  will  be  composed  of  sand  supplied 
from  a  suction  dredge  which  will  take  its  supply  from  the  bottom  of  the  sea,  or  earth, 
ashes  and  other  suitable  material. 

The  height  of  the  island  above  mean  low  water  will  be  about  18  feet.  The  length 
of  the  island,  when  first  constructed  will  be  about  1,300  feet  and  the  width  1,000  feet. 
The  side  of  the  riprap  wall  which  is  exposed  to  the  sea  will  have  a  slope  of  1  vertical 
upon  3  horizontal  and  the  two  adjoining  sides  will  have  an  outer  slope  of  about  1  on 
2.  The  riprap  will  be  15  feet  across  the  top  and  will  be  surmounted  by  a  concrete 
parapet  wall  4  feet  in  height.  The  riprap  will  be  from  75  to  122  feet  wide  on  the 
bottom,  according  to  the  location  with  respect  to  the  sea. 

The  island  will  contain  a  plant  of  settling  tanks  in  which  the  sewage  will  have  an 
opportunity  to  settle  and  deposit  its  solid  matters  during  a  period  of  about  two  hours. 
These  tanks  will  be  of  modified  Dortmund  tank  construction,  similar  to  those  recently 
constructed  at  Toronto,  Canada.  Provision  can  be  made  for  treating  the  sewage,  if 
necessary,  with  a  coagulant  before  passing  it  into  the  tanks. 

After  treatment,  the  sewage  will  be  discharged  through  a  number  of  outlets  ar- 
ranged radially  from  the  island  in  such  position  as  to  bring  about  the  most  immediate 
and  perfect  dispersion  of  the  sewage  practicable.  If  desirable,  it  will  be  feasible  to 
pump  sea  water  and  mix  it  with  the  sewage  before  the  discharge  takes  place.  Such 


128 


PLANS  FOR  THE  PROTECTION  OP  THE  HARBOR 


admixture  would  facilitate  the  immediate  diffusion  of  the  sewage  in  the  sea  water; 
but  the  active  agitation  and  free  movement  of  the  great  volume  of  water  in  the 
vicinity  of  the  island  will,  it  is  expected,  make  a  preliminary  mixture  of  sea  water  and 
sewage  by  pumping  unnecessary. 

The  material  which  will  settle  out  of  the  sewage  in  the  tanks  will  be  carried  to 
sea  in  vessels  and  dumped  sufficiently  far  from  the  land  to  insure  that  no  trace  will 
reach  bathing  beaches,  inhabited  shores  or  oyster  grounds. 

Provision  will  be  made  for  a  laboratory  and  dwelling  house  for  those  Avho  will  be 
needed  to  operate  the  tanks  and  other  devices  for  the  treatment  and  discharge  of  the 
sewage.  It  will  be  feasible  to  maintain  a  light  on  the  island  for  the  benefit  of  navi- 
gation, in  case  this  is  desirable. 

In  course  of  time,  it  will  be  necessary  to  increase  the  size  of  the  island  and  it  is 
proposed  that  this  will  be  done  by  extending  its  length  so  that  the  total  area  covered 
will  be  about  three  times  that  of  the  original  island,  or,  approximately,  70  acres. 

The  quantity  of  sewage  which  will  be  brought  to  the  island  at  the  beginning  is 
estimated  at  about  203,000,000  gallons  per  24  hours  during  dry  weather.  During 
storms,  this  volume  will  increase  about  100  per  cent.  This  sewage  will  be  collected 
from  those  parts  of  Manhattan  and  Brooklyn  whose  drainage  is  naturally  tributary  to 
the  Lower  East  river  between  the  Battery  and  2Sth  street,  Manhattan.  It  is  proposed 
to  collect  the  sewage  by  building  intercepting  sewers  close  to  the  water  front  to 
receive  the  sewage  from  the  existing  combined  sewers  and  gather  it  to  a  central  pump- 
ing station  to  be  located  near  the  Brooklyn  Navy  Yard.  A  siphon  built  beneath  the 
East  river  will  carry  the  sewage  of  Manhattan  to  the  Brooklyn  side.  At  the  central 
pumping  station  the  sewage  will  be  pumped  through  a  force  main  built  as  a  tunnel  to 
the  island.  The  tunnel  will  be  over  20  feet  beneath  the  bottom  of  the  Lower  bay  and 
so  be  free  from  injury  to  anchors  even  in  the  deepest  parts  of  the  channel  between  the 
island  and  the  mainland  where  vessels  rarely  anchor.  The  sewage  will  consist  of  the 
ordinary  dry-weather  flow  except  at  periods  of  rainfall  when  the  storm  water  from  the 
streets  will  also  be  received  to  the  extent  of  about  once  the  volume  of  the  average 
hourly  production  of  house  sewage. 

All  the  sewage  which  is  sent  to  the  island  will  have  been  passed  through  grit 
chambers  and  screens  with  openings  not  larger  than  one-half  inch.  The  sewage  from 
Manhattan  will  be  screened  before  passing  to  the  Brooklyn  side.  Since  it  will  be  rela- 
tively fresh,  it  is  estimated  that  no  less  than  15  per  cent,  of  the  suspended  matter  will 
be  extracted.  Grit  chambers  will  be  located  near  the  screens  and  their  efficient  opera- 
tion will  be  insured  by  the  necessity  which  will  exist  for  removing  the  readily  settle- 
able  material  from  the  sewage  in  order  to  prevent  obstructions  in  the  siphon  and 
interference  with  the  pumps.  The  Brooklyn  sewage  will  be  passed  through  screens 
and  grit  chambers  no  less  effective  than  those  of  Manhattan  before  the  sewage  is 
pumped  through  the  force  main.  It  is  estimated  that  the  settling  basins  on  the  island 
will  remove  at  least  60  per  cent,  of  the  suspended  matter  from  the  sewage.  It  is  ex- 
pected that  the  total  effect  of  the  treatment  by  grit  chambers,  screens  and  settling 
basins  will  be  to  remove  considerably  more  than  75  per  cent,  of  the  suspended  matter 
originally  present. 


LOWER  EAST  RIVER,  HUDSON  AND  BAY  DIVISION 


129 


It  is  believed  by  this  Commission  that  either  of  the  two  locations  here  proposed 
for  the  island  will  be  favorable  for  the  sanitary  disposal  of  the  sewage  and  will  be  free 
from  objection  from  the  standpoint  of  navigation.  Both  sites  are  upon  sand  reefs 
where  no  vessels  except  fishing  craft  of  lightest  draft  are  likely  to  pass.  The  area  of 
the  island,  even  when  extended  to  the  dimensions  which  may  ultimately  be  necessary, 
will  be  so  small,  as  compared  with  the  total  area  of  tbe  Lower  bay,  as  not  seriously 
to  interfere  either  with  the  tidal  prism  or  with  the  force  or  direction  of  the  tidal  cur- 
rents flowing  in  and  out  of  the  harbor.  The  amount  of  solid  matter  contained  in  the 
sewage  when  discharged  will  be  slight  as  compared  with  the  volumes  of  water  in  the 
vicinity  of  the  island  and  the  action  of  the  waves  and  currents  in  this  part  of  the 
harbor  are  so  active  that  it  seems  improbable  to  this  Commission  that  deposits  of  any 
serious  extent  would  be  formed,  even  if  the  sewage  was  to  be  discharged  in  crude 
condition. 

Apart  from  permission  to  build  the  island,  which  this  Commission  would  inter- 
pret as  expressing  a  belief  that  no  interference  would  be  caused  by  the  island  to  navi- 
gation, this  Commission  would  value  the  opinion  of  the  Harbor  Line  Board  as  to  the 
probable  capacity  of  the  island  to  resist  the  destructive  action  of  the  sea.  It  is  recog- 
nized that  the  Army  Engineers  possess  the  qualifications  of  experts  on  this  subject. 
If  material  criticism  can  be  brought  against  the  proposal  of  this  Commission  for  the 
construction  of  the  island  on  the  score  of  structural  defect,  suggestions  looking  to  a 
more  durable  form  of  construction  would  be  regarded  in  the  light  of  a  public  service. 

Accompanying  this  letter  is  a  chart  of  Lower  New  York  bay,  showing  the  two 
alternative  locations  for  the  proposed  island,  a  profile  giving  the  line  of  the  tunnel 
through  which  the  sewage  would  be  pumped  to  the  island,  a  plan  of  the  island  and 
three  cross  sections  of  the  retaining  walls. 

Respectfully, 

George  A.  Soper, 

President. 

Separate  Screening  Plants 

It  will  be  impracticable  to  remove  from  the  inner  harbor  all  the  sewage  from  the 
Lower  East  river,  Hudson  and  Bay  Division.  That  which  is  not  included  in  the 
recommended  project  for  the  Lower  East  river  will  be  treated  by  locally  placed  grit 
chambers  and  fine  screens  and  discharged  locally  through  submerged  outlets.  Mar- 
ginal sewers  will  be  necessary  to  concentrate  the  sewage  at  the  proposed  plants,  whose 
locations  are  shown  approximately  upon  the  frontispiece  to  this  report. 

Following  is  an  estimate  of  cost  of  a  few  typical  plants : 

Riverside  Park  at  West  96th  Street,  Manhattan 

A  fine  screening  plant  and  grit  chamber  would  be  located  in  Riverside  Park  at 
West  96th  Street,  with  submerged  outlets  extending  to  300  feet  off  the  West  96th  Street 
pier.    The  capacity  would  be  three  times  the  dry-weather  flow  of  30  million  gallons 


130 


PLANS  FOR  THE  PROTECTION  OF  THE  HARBOR 


per  day.  The  storm  outlets  carried  to  the  end  of  West  97th  Street  pier  would  have  a 
capacity  of  270  million  gallons  per  day. 

Estimate  of  Cost 


Treatment  Plant 

Excavation  $  9,000 

Sub-structure   13,500 

Superstructure   25,500 

Machinery   29,000 

Contingencies— 15%   12,000  $  89,000 


Outlets  for  Dry-Weather  Flow 

Treatment  plant  to  existing  sewer  $  1,200 

Present  outlet  to  300'  off  pierhead   23,000  24,200 


Outlets  for  Storm  Overflow 

Treatment  plant  to  bulkhead  line  $16,250 

Bulkhead  line  to  pierhead   20,750  37,000 


Total  cost  of  plant  and  outlets  $150,200 


Orchard  Street,  Astoria 

A  fine  screening  plant  and  grit  chamber,  with  pumps  for  low  level  sewage  only, 
would  be  located  at  the  foot  of  Orchard  Street,  Astoria.  The  capacity  would  be  87 
million  gallons  per  24  hours  or  three  times  the  dry-weather  flow. 

Estimate  of  Cost 


Excavation  $  4,662 

Substructure   10,250 

Superstructure   20,000 

Machinery   36,100 

Contingencies— 15%   10,688 


Total  Cost  $81,700 


Mth  Street,  Brooklyn 

A  fine  screening  plant  and  grit  chamber  would  be  located  at  the  foot  of  61th 
Street,  Brooklyn.  The  capacity  would  be  150  million  gallons  per  24  hours  or  three 
times  the  dry-weather  flow. 

Estimate  of  Cost 


Excavation  $  6,900 

Substructure   17,500 

Superstructure   65,400 

Machinery   35,000 

Connection  with  sewer   2,200 

Contingencies— 15%   20,000 


Total  Cost  $147,000 


ALTERNATIVE  PROJECTS  FOR  DISPOSING  OF  THE  SEWAGE  OF  THE 
LOWER  EAST  RIVER,  HUDSON  AND  BAY  DIVISION 

Possible  Directions  in  Which  to  Take  the  Sewage 

There  are  not  many  directions  in  which  the  sewage  from  the  Lower  East  River 
Section  can  be  taken.  It  would  be  impracticable  to  carry  it  north  into  Westchester 
County,  for  the  land  there  lies  at  too  great  an  elevation.    It  would  be  impossible  to 


LOWER  EAST  RIVER,  HUDSON  AND  BAY  DIVISION  131 

carry  it  west  because  the  people  of  New  Jersey  would  object  to  receiving  it.  The  idea 
of  discharging  it  into  the  Hudson  river  cannot  be  entertained,  for  if  this  were  done 
that  stream  would  become  too  heavily  polluted.  Sentimental  considerations  require 
that  the  Hudson  shall  not  be  made  a  receptacle  for  the  sewage  from  other  parts  of  the 
harbor. 

It  would  not  be  feasible  to  carry  the  sewage  to  Long  Island  sound;  the  distance 
would  be  too  great,  the  volume  of  water  there  available  would  be  insufficient,  the 
danger  of  polluting  extensive  shellfish  beds  would  be  large,  and  the  risk  of  contami- 
nating the  shores  in  the  vicinity  of  villages,  towns  and  country  estates  too  imminent. 

The  sewage  could  not  be  taken  east  on  Long  Island,  except  to  a  distance  of  30  or 
40  miles,  for  its  disposal  would  be  certain  to  produce  nuisance  and,  consequently, 
serious  injury  to  property  already  occupied  for  residence  purposes  or  likely  soon  to  be- 
come valuable  for  this  purpose.  Furthermore,  opportunities  for  the  disposal  of  the 
effluent  of  treatment  works  are  lacking  on  Long  Island,  the  north  shore  of  which  is 
deeply  indented  with  bays  and,  for  the  most  part,  high  and  rocky,  and  the  south  shore 
bordered  with  broad,  shallow  bays  and  marshy  islands,  where  the  flow  of  tidal  water 
is  relatively  slight. 

Staten  Island  Not  Suitable  for  Very  Large  Sewage  Works 

To  the  southwest  of  this  division  lies  the  Borough  of  Richmond,  or  Staten  Island, 
and  much  sewage  could  be  brought  there  for  treatment  as  far  as  engineering  consider- 
ations are  concerned.  There  are  several  thousand  acres  of  marshy  land  on  the  west 
side  of  this  island  bordering  the  Arthur  Kill  which  might  be  employed  for  sewage  dis- 
posal, provided  no  nuisance  were  produced. 

The  sewage  could  be  taken  to  the  disposal  works  by  a  tunnel  which  could  be 
driven  beneath  the  waters  of  Upper  New  York  bay  to  the  north  shore  of  Staten 
Island,  and  thence  through  the  high  land  to  the  low-lying  area  near  the  Arthur  Kill. 
The  Arthur  Kill  has  been  dredged  for  the  convenience  of  ships  and  could  receive  a 
well  purified  effluent,  although  owing  to  its  small  volume  of  flow  and  the  oscillating 
effect  of  the  tide,  the  capacity  of  the  Arthur  Kill  for  unpurified  sewage  is  compara- 
tively small.  If  the  sewage  could  not  be  purified  sufficiently  to  discharge  the  effluent 
into  the  Arthur  Kill,  it  would  have  to  be  carried  by  tunnel  eastward  from  the  treat- 
ment works  to  the  waters  of  Lower  New  York  bay. 

It  is  probable  that  treatment  works  capable  of  purifying  the  sewage  to  such  an 
extent  as  would  permit  the  effluent  to  be  discharged  into  the  Arthur  Kill  would  be 
impracticable  on  Staten  Island.  Apparently  some  oxidizing  process,  either  sprink- 
ling filters  or  possibly  contact  beds,  would  have  to  be  employed.    It  is  probable  that 


132  PLANS  FOR  THE  PROTECTION  OF  THE  HARBOR 

if  either  of  these  processes  were  used  to  treat  the  quantity  of  sewage  which  would 
have  to  be  dealt  with,  not  less  than  200,000,000  gallons  per  24  hours,  with  a  certainty 
of  more  later  on,  objectionable  sanitary  conditions  would  be  produced.  The  sewage 
would  be  septic  and,  consequently,  likely  to  produce  odor  when  brought  into  contact 
with  the  air  either  in  the  fine  spray  necessary  in  sprinkling  filters  or  in  the  large  areas 
of  surface  exposed  by  the  broken  stone  of  contact  beds.  The  likelihood  of  trouble 
from  flies,  a  frequent  and  annoying  feature  in  sewage  works,  should  also  be  consid- 
ered. The  peculiar  mist  which  sometimes  hovers  in  calm  weather  over  extensive  areas 
of  sprinkling  filters  would  prove  a  source  of  grave  concern  to  property  holders,  even 
at  a  considerable  distance  from  the  works.  Before  the  authorities  of  the  Borough  of 
Richmond  would  give  their  consent  to  receiving  the  sewage  of  this  division  in  that 
borough  for  disposal,  it  is  probable  that  they  would  insist  upon  more  assurance  of 
immunity  from  nuisance  than  safely  could  be  given. 

Added  to  the  sanitary  difficulties  which  would  attach  to  the  disposal  of  the  sew- 
age by  works  upon  Staten  Island  is  the  consideration  of  cost.  It  would  be  expensive 
to  carry  the  sewage  of  this  division  to  Staten  Island  and  there  dispose  of  it.  The  tun- 
nels would  be  long  and,  in  places,  very  deep.  The  foundations  for  the  works  on  the 
lowlands  in  the  western  part  of  Staten  Island  might  prove  difficult  of  construction. 
The  outlet  tunnel  for  the  effluent  would  be  long  and  costly. 

Possibility  of  Treatment  on  an  Artificial  Island  in  the  Inner  Harbor 

The  Commission  has  made  an  investigation  of  alternative  projects  for  carrying 
the  sewage  of  the  Lower  East  river  section  to  an  artificial  island  nearer  than  the  pro- 
posed sea  island. 

The  first  alternative  contemplated  an  island  of  about  20  acres  just  south  of,  or 
built  as  an  extension  to,  Blackwells  Island  in  the  East  river.  The  treatment  proposed 
was  chemical  precipitation,  the  sludge  to  be  carried  by  steamers  to  sea  and  dumped 
there.  After  treatment,  the  sewage  would  be  discharged  into  the  East  river  through 
three  submerged  outfalls.  The  sewage  would  be  collected  from  the  Manhattan  and 
Brooklyn  shores  by  interceptors  built  above  tidal  influence,  the  district  lying  between 
the  interceptor  and  the  shore  to  be  resewered  so  as  to  drain  into  the  interceptor.  The 
collectors  were  designed  to  carry  twice  the  the  mdwf.*  expected  by  1960. 

Pumping  stations  would  be  located  at  Corlears  Hook,  Manhattan,  Wallabout 
Street,  Brooklyn,  and  on  the  proposed  island.  The  sewage  would  pass  through  screens 
and  grit  chambers  before  reaching  the  pumps. 

*Mean  dry-weather  flow. 


LOWER  EAST  EIVER,  HUDSON  AND  BAY  DIVISION  133 

The  cost  would  be  f 20,694,000,  and  the  annual  charges  $2,117,700.  These  amounts 
are  larger  than  the  estimates  for  the  ocean  island  project,  and  the  project  would  not 
afford  as  much  relief  to  the  Lower  East  river. 

The  second  alternative  involved  the  construction  of  an  island  in  the  Upper  bay, 
off  Red  Hook,  just  south  of  Governors  Island.  The  method  of  collection  was  to  be 
similar  to  that  proposed  in  the  Blackwells  Island  scheme.  The  screens  and  grit 
chambers  would  be  located  at  Corlears  Hook,  Manhattan,  Borden  Avenue,  Queens,  and 
Wallabout  Street,  Brooklyn.  The  single  pumping  station  would  be  located  at  the 
island.   The  estimated  cost  was  $23,933,000  and  the  annual  charges  $2,309,400. 

The  point  of  discharge  would  be  almost  in  the  path  of  vessels  in  the  main  channel. 
The  sewage  would  be  carried  to  the  Lower  East  river  by  the  flood  currents,  thus  defeat- 
ing the  purpose  for  which  it  was  taken  to  the  island.  The  proposed  Passaic  Valley 
Sewer  outlet  would  be  about  2y2  miles  distant,  and  it  is  probable  that  the  combined 
volume  of  sewage  from  these  two  outlets,  even  after  partial  purification,  would  over- 
burden this  part  of  the  Upper  Bay. 

Objections  to  Collection  at  Barren  Island 

Two  other  possible  means  of  disposing  of  the  sewage  of  this  division  remain  to 
be  considered.  First,  collection  to  the  vicinity  of  Barren  Island,  near  the  mouth  of 
Jamaica  bay,  and  treatment  there,  with  a  discharge  of  the  effluent  at  sea.  Sanitary 
considerations,  such  as  have  been  mentioned  in  connection  with  the  possibility  of 
carrying  the  sewage  to  Staten  Island,  would  weigh  heavily  against  purifying  the  sew- 
age any  more  completely  than  is  absolutely  necessary  at  this  point.  The  outlet  would 
therefore  have  to  be  long  enough  to  carry  the  sewage  far  from  shore. 

Unless  the  sewage  were  purified  in  bacteria  beds,  it  would  be  necessary  to  extend 
the  outlet  some  miles  out  to  sea  beyond  Rockaway  Point  in  order  to  make  sure  that 
the  sewage  would  not  be  carried  back  to  the  land  by  the  wind  and  tide,  and  there  are 
practical  difficulties  in  the  way  of  doing  this.  The  necessary  tunnel  for  this  purpose 
would  be  very  difficult  to  construct.  It  would  have  to  be  at  least  75  feet  below  the 
surface  of  the  water,  in  order  to  cross  well  beneath  the  deep,  swiftly-flowing  channels 
of  Rockaway  inlet.  The  water  at  this  point  is  between  40  and  50  feet  deep  at  low  tide. 
Proceeding  seaward  it  would  not  be  found  desirable  to  approach  much  nearer  the 
surface  with  it.  The  point  of  outfall  should  probably  be  located  about  two  miles  from 
shore.  This  would  be  an  unfavorable  location  for  an  outlet  crib  or  other  permanent 
structure,  for  it  would  be  exposed  to  the  full  force  of  the  Atlantic  ocean  and  the  shift- 
ing sands.    This  project  thus  has  weighty  arguments  against  it. 


134 


PLANS  FOR  THE  PROTECTION  OF  THE  HARBOR 


Estimate  of  Cost  of  Disposing  of  250  Million  Gallons  of  Sewage  Per  Day  from  a  Crib 


As  far  as  the  Lower  East  river,  Hudson  and  Bay  Division  is  concerned,  the  scheme 
is  practically  identical  with  that  outlined,  hut  in  this  plan  the  sewage  from  that  part 
of  the  Jamaica  Bay  Division  located  in  Brooklyn  would  be  added  to  the  sewage 
from  the  Lower  East  river,  Hudson  and  Bay  Division  at  the  Coney  Island  pumping 
station  after  passing  grit  chambers  and  screens.  The  part  relating  to  the  Jamaica 
Bay  Division  may  be  considered  a  revision  of  the  recommended  project,  but  with  the 
Coney  Island  pumping  station  near  caisson  No.  3,  instead  of  Barren  Island,  the  objec- 
tive point  of  concentration. 

The  estimates  are  based  on  the  1915  flow  from: 


The  sizes  of  interceptors  are  based  upon  the  anticipated  sewage  flow  of  1960  except 
in  crossing  the  East  river  and  Coney  Island  ship  canal  and  running  northerly  from 
the  Wallabout  pumping  station  in  Brooklyn.  These,  with  the  outfall  tunnel  between 
the  Wallabout  pumping  station  and  the  outlet,  would  require  duplicating  in  order  to 
accommodate  the  flow  expected  in  1960. 

The  Jamaica  Bay  Interceptor.  On  account  of  the  flat  topography,  the  sizes  and 
gradients  are  calculated  for  velocities  of  2y2  feet  per  second  when  half  full.  This  fixes 
the  diameter  at  the  26th  ward  plant  at  9  feet,  which  would  increase  to  12  feet  4  inches  by 
the  time  it  joined  the  Gravesend  interceptor  at  Ocean  Parkway.  From  this  point,  the 
interceptor  would  continue  to  the  Coney  Island  pumping  station  with  a  diameter  of  13 
feet  3  inches  passing  under  the  Coney  Island  ship  canal  in  a  66-inch  cast-iron  siphon. 

The  Gravesend  interceptor  would  be  4  feet  and  the  Shellbank  interceptor  27  inches 
in  diameter. 

Jamaica  Bay  Pumping  Stations.  Owing  to  the  increased  depth  between  Flatbush 
Avenue  and  Ocean  Parkway  over  that  in  Project  O,*  made  necessary  by  the  reversed 
direction  of  flow  to  the  westward,  the  sewage  from  Caisson  No.  3,  Caisson  No.  4  (Shell- 
bank  treatment  plant)  and  Ocean  Parkway  would  not  have  to  be  pumped.  There  would, 
therefore,  be  no  pumping  required  at  the  main  interceptors  between  the  existing 
"Gravesend"  pumping  station  at  Bensonhurst  and  the  present  East  New  York  treat- 
ment plant. 

*The  recommended  project  for  Jamaica  Bay.    See  Chapter  V. 


Outlet  in  Lower  New  York  Bay 


Manhattan — Lower  East  river,  Hudson  and  Bay  Division 
Brooklyn   —    "       "        "        "        "     "  " 
Brooklyn   — Jamaica  Bay  Division  


99  mgd. 
104  " 
47  " 


Total 


250  mgd. 


LOWER  EAST  RIVER,  HUDSON  AND  BAY  DIVISION  135 

To  raise  the  sewage  from  adjacent  territory  there  would  be  required  the  following 
pumping  stations : 

East  New  York.  Paerdegat  Gravesend 

Mean  Flow   23 . 7  mgd.  14 . 3  mgd.  3 . 3  mgd. 

It  is  assumed  that  the  present  building  at  East  New  York  could  be  utilized  for  this 
purpose,  in  which  case  a  new  pumping  station  at  Paerdegat  would  be  the  only  one  re- 
quired for  the  Jamaica  Bay  Division. 

Outlet.  The  submerged  outfall  tunnel  would  be  14  feet  in  diameter,  laid  to  a  crib 
in  the  Lower  Bay. 

Cost.  The  entire  cost  of  construction,  as  outlined  above,  adequate  to  handle  250 
mgd.  sewage  at  first  with  provision  for  extension,  is  estimated  at  $20,984,000,  and  the 
annual  charges,  including  interest  and  sinking  fund,  at  f 1,623,000. 

Locally  Placed  Settling  Tanks 

This  project  contemplates  treating  the  sewage  of  subdivisons  13,  14,  15,  24,  25  and 
26  of  the  Lower  East  river,  Hudson  and  Bay  Division  by  independent  sedimentation 
plants. 

It  is  assumed  that  these  six  treatment  plants  would  be  located  on  what  is  now  pri- 
vate property  in  the  vicinity  of  the  points  of  collection,  and  that  marginal  collecting 
sewers,  tide  gates  and  regulators  would  be  provided. 

At  the  points  of  collection  the  sewage  would  be  passed  through  coarse  cage  screens 
and  grit  chambers  and,  where  necessary,  would  be  pumped  so  as  to  provide  ample  head 
for  delivery. 

For  sedimentation  modified  Dortmund  tanks  would  be  provided,  each  hopper  serv- 
ing an  independent  unit  30x30  feet  in  size  inside.  These,  being  on  private  property, 
would  not  require  the  costly  reinforced  concrete  necessary  for  Emscher  tanks  placed 
under  the  street  surface. 

The  capacity  of  each  tank  when  empty  would  be  11,500  cu.  ft.,  giving  a  period  of 
retention  of  2  hours,  and  the  depth  from  surface  of  sewage  to  the  bottom  of  hopper, 
inside,  would  be  22.8  ft.  As  sludge  would  be  drawn  off  daily  there  would  be  but  little 
accumulation  to  shorten  the  above  period  of  detention  for  the  dry-weather  flow.  The 
maximum  flow  assumed  would  be  three  times  the  dry-weather  flow,  the  surplus  passing 
by  storm  overflows  directly  to  the  river. 

The  cost  of  land  for  the  treatment  plants  is  very  difficult  to  estimate,  but  in  order 
to  cover  the  cost  of  such  buildings  as  may  exist  on  the  lots  taken  for  the  purpose  and 
their  removal  it  is  based  on  twice  the  highest  price  per  front  foot  given  for  property 


136  PLANS  FOR  THE  PROTECTION  OF  THE  HARBOR 

that  appears  to  be  most  suitable  for  tbe  purpose,  as  stated  in  "Land  Value  Maps  of 
the  City  of  New  York  for  1911."*    Reduced  to  prices  per  square  foot  these  are,  for: 


Subdivision 

13 

14 

15 

24 

25 

26 

Location 

Roosevelt 
Street 

Broome 
Slip 

E.  14th 
Street 

So.  5th 
Street 

Hudson 
Street 

Adams 
Street 

Price  per  square  foot  

$12.00 

$6.50 

$5.50 

$6.00 

$6.00 

$10.00 

From  the  tanks  the  sewage  would  pass  directly  to  the  river  by  submerged  outlets 
by  one  or  more  36-inch  pipes.  Although  the  number  and  size  of  these  would  be  deter- 
mined by  the  flow  to  be  expected  from  each  plant,  it  has  been  deemed  sufficient  for  the 
present  purpose  to  provide  one  36-inch  outlet  for  each  12  million  gallons  per  day  of 
mean  dry- weather  flow. 

Sludge  and  screenings  would  be  taken  daily  by  a  sludge  steamer  of  1,000  tons  ca- 
pacity and  dumped  4  miles  E.S.E.  of  Scotland  Light  Vessel.  The  volume  so  disposed  of 
is  assumed  as  5  cu.  yds.  per  million  gallons  of  sewage  or  1,015  cu.  yds.  at  0.86  tons=8T3 
tons  per  day.  The  distance  traveled  would  be  about  10  miles  while  calling  at  the  six 
plants  in  the  East  river  to  fill  and  50  miles  from  the  Battery  to  the  dumping  ground 
and  back.  One  vessel  could  accomplish  this,  working  night  and  day,  but  to  allow  for 
contingencies  two  vessels  would  be  provided  each  loading  one  day  and  dumping  the  next 
or  else  doing  both  on  alternate  days.  In  spite  of  some  lost  time  or,  it  might  be  said, 
excess  capacity  of  steamer,  it  probably  would  not  be  wise  to  provide  for  less  with  the 
certainty  of  a  continuous  increase  of  output  which  would  soon  necessitate  more  ade- 
quate provision. 

Capacities  are  based  on  sewage  volumes  forecast  for  1915,  and  the  only  additional 
cost  for  increased  volumes  will  be  for  treatment  plants  and  sludge  disposal. 

The  cost  of  construction  is  estimated  at  .$6,901,000  and  the  annual  charges  at 
|552,230. 


TABLE  XVII 
Data  Relating  to  Locally  Placed  Settling  Tanks 


Sub-division 

13 

14 

15 

24 

25 

26 

Total 

Population,  1915  

202650 

264300 

221000 

310310 

401500 

23500 

1423720 

Mean  dry-weather  flow  in  mgd  

42 

25 

32 

34 

66 

4 

203 

No.  tanks  at  1.05  mgd  

40 

24 

30 

32 

58 

4 

188 

Area  req'd  @  .04  ac.  each  

1.60 

.96 

1.20 

1.28 

2.32 

.16 

7.52 

Cubic  yds.  sludge  daily  @  5  per  mg  

210 

125 

160 

170 

330 

20 

1015 

No.  Outlet  pipes  @  12  mgd.  each  

4 

2 

3 

3 

6 

1 

19 

Cost  of  screening  plants  

$99800 

$77000 

$87100 

$89800 

$125100 

$30800 

$509600 

Cost  of  land  for  plants  

$40000 

$19000 

$15000 

$10000 

$25400 

$109400 

•The  Record  &  Guide  Co.— Publishers. 


LOWER  EAST  RIVER,  HUDSON  AND  BAY  DIVISION  137 

Comparative  Cost  of  Conveying  487  Million  Gallons  of  Seicage  Per  Day  from  the  Lower 
East  River  Section  to  Various  Points  for  Disposal 

Following  are  comparative  estimates  of  the  cost  of  conveying  the  forecast  sewage 
entering  the  East  River,  amounting  to  487  mgd.,  to  different  points  for  disposal.  The 
costs  of  collecting  the  sewage  to  a  pumping  station  near  the  Navy  Yard  or,  in  the  case 
of  disposal  on  Staten  Island  near  Linoleum vi lie,  to  the  Battery,  are  not  included  in 
the  estimates: 

A.    Intermittent  discharge  of  crude  sewage  on  outgoing  tidal  currents  from  an 


artificial  island  between  Ambrose  Channel  and  Coney  Island. 

Cost  of  construction  $22,120,000 

Annual  cost : 

Operation  and  maintenance   $1,338,700 

Fixed  charges   1,119,300 

$2,458,000 

B.  Continuous  discharge  of  screened  sewage  from  an  artificial  island  between 
Ambrose  Channel  and  Coney  Island. 

Cost  of  construction  $18,480,000 

Annual  cost : 

Operation  and  maintenance   $1,454,000 

Fixed  charges   935,000 

$2,389,000 

C.  Continuous  discharge  from  an  artificial  island  between  Ambrose  Channel  and 
Coney  Island  after  passing  through  Emscher  tanks. 

Cost  of  construction  $21,013,000 

Annual  cost: 

Operation  and  maintenance   $1,560,900 

Fixed  charges   1,063,300 

$2,624,200 

D.  Discharge  from  submerged  outlet  in  the  ocean  off  Rockaway  Point  after 
screening  on  Barren  Island. 

Cost  of  construction  $19,837,000 

Annual  cost : 

Operation  and  maintenance   $1,144,300 

Fixed  charges   1,003,700 

$2,148,000 


138  PLANS  FOR  THE  PROTECTION  OF  THE  HARBOR 

E.  Discharge  from  submerged  ocean  outlet  off  Rockaway  Point  after  passing 
through  Einscher  tanks  on  Barren  Island. 

Cost  of  construction  $22,492,000 

Annual  cost: 

Operation  and  maintenance   $1,196,100 

Fixed  charges   1,138,100 

$2,334,200 

F.  Discharge  to  Rockaway  Inlet  after  passing  Emscher  tanks  and  sprinkling 
filter  on  Barren  Island. 

Cost  of  construction  $26,331,000 

Annual  cost: 

Operation  and  maintenance   $1,743,900 

Fixed  charges   1,332,400 

$3,076,300 

G.  Discharge  to  Fresh  Kills  after  passing  Emscher  tanks  and  sprinkling  filters 
near  Linoleumville,  Staten  Island. 

Cost  of  construction  $30,058,000 

Annual  cost: 

Operation  and  maintenance   $1,626,600 

Fixed  charges   1,520,900 

$3,147,500 

The  above  figures  indicate  that  treatment  by  sprinkling  filters  either  on  Barren 
Island  or  Linoleumville  would  be  far  more  costly  than  the  other  schemes,  while  the 
two  least  expensive  are  those  involving  screening  only.  If  the  point  of  disposal,  in  the 
latter  case,  were  from  an  artificial  island  off  Coney  island 

the  first  cost  would  be  $18,480,000 

and  the  annual  charges   2,389,000 

while  if  the  discharges  were  in  deep  water  off  Rockaway  Point 

the  first  cost  would  be  $19,837,000 

and  the  annual  charges   2,148,100 

Recapitulation  of  Lower  East  River  Projects 

Aside  from  various  plans  which  have  been  made  for  carrying  the  sewage  of  New 
York  to  sea  or  to  a  central  point  for  treatment,  there  have  been  developed  seventeen 
projects  for  the  disposal  of  the  sewage  of  the  Lower  East  river. 

Of  these  projects,  thirteen  contemplated  the  complete  removal  of  the  sewage  from 


LOWER  EAST  RIVER,  HUDSON  AND  BAY  DIVISION  139 

this  vicinity,  two  to  an  outlet  crib  in  the  Lower  Bay,  where  it  would  be  discharged 
continuously,  without  other  treatment  than  coarse  screening  before  pumping,  and 
eleven  to  an  artificial  outlet  island  at  the  same  location,  the  treatment  to  consist  of 
fine  screening  in  one  case  and  of  sedimentation  in  the  other  ten.  These  projects  dif- 
fered chiefly  in  the  arrangement  of  interceptors  and  marginal  sewers,  territory  in- 
cluded, and  amount  of  sewage  provided  for.  In  two  of  these  plans,  removal  to  the 
ocean  outlet  island  was  contemplated  as  a  final  installation  only,  local  treatment  by 
fine  screening  being  recommended  as  a  first  step  in  the  construction.  The  project 
described  in  detail  and  recommended  by  the  Commission  and  its  consulting  engineers 
is  one  of  these. 

Of  the  four  remaining  projects,  two  contemplated  treatment  by  locally  placed 
settling  tanks,  grit  chambers  and  screens,  with  discharge  of  the  clarified  effluent  into 
the  Lower  East  river.  Two  others  involved  treatment  by  chemical  precipitation  on 
artificial  islands,  one  located  south  of,  or  as  an  extension  to,  Blackwells  Island  in  the 
Lower  East  river,  the  other  off  Red  Hook,  south  of  Governors  Island,  in  the  Upper 
bay. 

The  plan  of  intercepting  the  existing  system  of  sewers  was  in  all  cases  practically 
the  same,  either  by  marginal  sewers  feeding  large  interceptors,  or  by  interceptors 
alone,  paralleling  the  water-front,  excepting  in  Projects  VIII  and  IX,  in  which  the 
laterals  were  intercepted  inland,  above  the  influence  of  the  tide,  and  the  territory 
between  the  interceptor  and  water-front  was  resewered  to  drain  towards  the  former. 

Only  one  project,  No.  I,  dealt  with  both  the  Harlem  river  and  Western  Jamaica 
sewage  in  addition  to  that  of  the  Lower  East  river,  while  one  other,  No.  Ill,  dealt 
with  the  Western  Jamaica  sewage.  Most  of  the  ocean  island  outlet  projects  contem- 
plated, as  a  final  installation,  the  removal  of  the  sewage  of  the  Western  Jamaica 
subdivision. 

The  quantities  of  sewage  provided  for  varied  from  133  to  987  mgd.  The  smaller 
figure  is  for  Project  XIII,  first  installation,  consisting  of  the  screening  and  subse- 
quent discharge  into  the  East  river  of  the  sewage  from  subdivisions  13,  14  and  15  in 
Manhattan,  and  24  in  Brooklyn.  The  second  figure  is  for  Project  I,  consisting  of  the 
removal  to  sea  of  the  sewage  tributary  to  the  East  river  below  Hell  Gate,  subdivisions 
13  to  26,  inclusive,  with  the  Wards  Island  flow  and  that  of  the  Western  Jamaica  sub- 
division. The  costs  ranged  from  $2,506,550  for  Project  XVI,  consisting  of  screening 
and  discharging  from  local  plants  the  sewage  of  subdivisions  13  to  15  in  Manhattan 
and  24  to  26  in  Brooklyn,  to  $42,824,000  for  Project  I,  as  described  above. 


CHAPTER  VII 


FORM  OF  ADMINISTRATION  RECOMMENDED  FOR  THE  PROTECTION 
OF  NEW  YORK  HARBOR  AGAINST  EXCESSIVE 
SEWAGE  POLLUTION 

INTRODUCTORY 

In  its  report  issued  April  30,  1910,  the  Metropolitan  Sewerage  Commission 
described  the  conditions  of  sewerage  and  sewage  disposal  for  the  metropolitan  area 
of  New  York  and  New  Jersey  and  showed  that  the  disposal  of  the  sewage  produced  in 
this  large  territory  was  without  control  or  regulation  of  any  kind.  The  total  extent 
of  land  and  water  included  in  the  district  was  about  700  square  miles.  The  popula- 
tion in  1910  was  about  6,000,000  and  the  number  of  municipalities  exceeded  80. 
Every  city  and  town  was  permitted  to  collect  and  dispose  of  its  sewage  in  such  quan- 
tity and  in  such  manner  as  it  saw  fit.  It  was  customary  to  discharge  into  the  nearest 
arm  of  the  harbor  with  little  or  no  regard  to  the  volume  of  dilutiug  water  available  at 
the  point  of  outlet  and  without  respect  to  the  nuisance  or  injury  to  health  which  might 
be  produced  before  the  sewage  was  finally  assimilated  by  the  forces  of  nature. 

Lack  of  administration  over  the  discharge  of  sewage  had  resulted  in  grave  sani- 
tary evils  not  only  to  the  municipalities,  but  elsewhere.  Some  of  the  sewers  had  been 
badly  designed  and  constructed.  In  a  large  number  of  instances,  the  outlets  were 
flooded  by  the  tides,  in  consequence  of  which  the  sewage  was  driven  back  and  afforded 
an  opportunity  to  deposit  and  putrefy.  The  discharge  of  sewage  usually  took  place 
into  inadequate  currents,  with  the  result  that  many  of  the  cities  and  towns  polluted 
their  own  shores  and  waterways  to  a  serious  extent.  With  the  increasing  quantities  of 
sewage  which  the  rapidly  growing  population  would  produce,  the  harmful  consequences 
of  the  chaotic  methods  of  sewage  disposal  would  be  certain  to  multiply. 

In  the  Commission's  opinion,  the  problem  of  disposing  of  the  sewage  of  the  metro- 
politan district  should  be  considered  without  regard  to  State,  municipal  or  other 
political  boundaries.  The  metropolitan  area  was  tolerably  well  defined  by  topograph- 
ical conditions  and  by  the  distribution  of  population  and  the  various  parts  of  this 
territory  were  so  related  that  the  sewage  of  no  section  could  be  disposed  of  without 
reference  to  the  health  and  welfare  of  others. 

The  harbor  waters  represented  a  great  financial  asset  so  far  as  sewage  disposal 
was  concerned,  inasmuch  as  it  was  evident  that  large  quantities  of  sewage  could  be 
discharged  into  the  harbor  without  harmful  consequences  if  the  sewage  was  prepared 


FORM  OF  ADMINISTRATION  RECOMMENDED  141 

for  this  method  of  disposal  by  suitable  treatment  and  the  discharges  were  arranged 
to  take  place  under  advantageous  circumstances. 

The  Commission  recommended  that  an  interstate  metropolitan  district  and  com- 
mission be  established  for  the  central  regulation  of  the  disposal  of  the  sewage  of  that 
part  of  New  York  and  New  Jersey  whose  natural  drainage  was  immediately  tributary 
to  New  York  harbor. 

Since  the  report  of  1910  was  issued,  further  study  has  been  made  of  the  form  of 
administration  necessary  for  the  metropolitan  area  of  New  York  and  New  Jersey  and 
the  results  of  this  study  are  set  forth  in  the  following  pages. 

In  addition  to  the  form  of  supervisory  control  which  it  will  be  desirable  to  estab- 
lish over  the  disposal  of  sewage  in  the  metropolitan  district,  provision  should  be  made 
for  a  proper  administration  of  such  works  of  main  drainage  and  disposal  as  are  re- 
quired. No  single  connective  system  for  the  collection  and  disposal  of  the  sewage  of 
the  entire  territory  is  required.  Any  plan  for  collecting  all  the  sewage  to  a  central 
point  for  disposal  would  be  extravagantly  costly  and  would  be  unnecessary.  The  funda- 
mental principle  which  should  govern  the  design  of  the  main  drainage  and  disposal 
works  required  should  be  to  make  full  use  of  the  digestive  capacity  of  the  harbor 
waters  and  the  reasonable  application  of  this  principle  requires  that  the  sewage  after 
proper  preparation  shall  be  discharged  at  a  large  number  of  points  throughout  the 
harbor.  This  plan  will  necessarily  require  the  construction  of  a  series  of  systems  of 
main  drainage  and  disposal,  rather  than  a  single  united  system.  Careful  attention 
should  be  given  in  each  case  to  the  operation  of  all  the  works  and  the  several  units, 
of  which  the  composite  whole  is  made  up,  should  be  most  carefully  and  intelligently 
coordinated. 

In  some  instances  the  main  drainage  works  for  the  disposal  of  the  sewage  of  a 
large  part  of  the  territory  should  lie  within  the  limits  of  a  single  municipality;  in 
other  cases  various  municipalities  should  combine. 

By  far  the  most  important  works,  as  well  as  those  of  the  most  immediate  necessity 
will  be  required  for  the  City  of  New  York.  This  fact  became  evident  early  in  the 
Commission's  investigations  and  since  the  1910  report  was  made  a  very  large  share  of 
the  Commission's  attention  has  been  given  to  the  design  of  the  works  required  by  that 
city.  , 

It  will  be  possible  and  desirable  for  the  works  of  main  drainage  and  sewage  dis- 
posal for  New  York  to  be  confined  to  that  city  and  yet  physically  united  with  the 
main  drainage  structures  which  may  be  required  in  the  adjoining  territory.  In 
another  report,  the  Metropolitan  Sewerage  Commission  has  described  the  works  which 
New  York  should  construct.    In  the  following  pages  is  given  the  plan  of  administra- 


142  PLANS  FOR  THE  PROTECTION  OF  THE  HARBOR 

tion  which  the  Commission  considers  desirable  for  the  construction  and  maintenance 
of  the  necessary  structures. 

QUESTIONS  RAISED  BY  THE  LEGISLATURE  AND  ANSWERS 

The  Act  of  Legislature  which  provided  for  the  creation  of  the  Metropolitan  Sewer- 
age Commission  submitted  four  principal  questions  for  the  Commission  to  investigate 
and  express  an  opinion  upon. 

The  act  asks : 

1.  Whether  it  is  desirable  and  feasible  for  New  York  City  and  the  municipalities 
in  its  vicinity  to  agree  upon  a  general  plan  or  policy  of  sewerage  and  sewage  disposal 
which  will  protect  the  waters  of  New  York  bay  and  vicinity  against  unnecessary  and 
injurious  pollution  by  sewage  and  other  wastes? 

2.  What  methods  of  collecting  and  disposing  of  the  sewage  and  other  wastes 
which  pollute,  or  may  eventually  pollute,  the  waters  contemplated  in  this  act  are  most 
worthy  of  consideration? 

3.  Whether  it  is  desirable  to  establish  a  sewerage  district  in  order  properly  to 
dispose  of  the  wastes,  and  adequately  protect  the  purity  of  the  waters  contemplated 
in  this  act,  and,  if  so,  what  should  be  the  limits  and  boundaries  of  this  sewerage 
district? 

4.  What  would  be  the  best  system  of  administrative  control  for  the  inception, 
execution  and  operation  of  a  plan  for  sewerage,  and  ultimate  sewage  disposal,  of  a 
metropolitan  sewerage  district;  whether  by  the  action  of  already  existing  departments 
and  provisions  of  government,  by  the  establishment  of  separate  and  distinct  sewer- 
age districts  and  permanent  commissions  in  each  State,  by  one  interstate  metropolitan 
sewerage  district  and  commission  to  be  established  by  agreement  between  the  two 
States,  this  agreement  if  necessary  to  be  ratified  by  Congress  or  by  other  means? 

The  Commission  finds  that: 

1.  It  would  not  be  possible  to  protect  the  waters  of  New  York  bay  and  vicinity 
by  inter-city  agreement.  There  are  about  80  municipalities  concerned  and  the  subject 
would  be  beyond  their  capacity  to  regulate  properly.  Existing  departments  and  pro- 
visions of  government  cannot  appropriately  nor  adequately  deal  with  this  question. 

2.  Extensive  main  drainage  works  are  required  for  the  protection  of  the  harbor, 
such  as  have  been  built  for  many  other  large  cities  and  towns,  the  essential  features 
of  the  necessary  structures  being  intercepting  and  collecting  stations,  where  the  sew- 
age can  be  purified  to  a  greater  or  lesser  degree,  depending  on  the  requirements,  and 
finally  discharged  into  the  tidal  water. 


FORM  OF  ADMINISTRATION  RECOMMENDED  143 

3  and  4.  There  should  be  two  forms  of  administration  provided  for.  One  of  these 
should  be  of  a  general  and  supervisory  nature  and  have  jurisdiction  over  the  entire 
metropolitan  territory  of  New  York  and  New  .Jersey.  The  other  should  be  for  the 
construction  and  maintenance  of  the  works. 

The  duties  of  the  supervisory  body  should  be  to  compel  cities  and  parts  of  cities 
within  the  district  to  carry  out  such  works  as  may  be  necessary  for  the  common  wel- 
fare and  to  improve  those  parts  of  the  harbor  which  threaten  to  give  rise  to  nuisance 
of  local  character.  Other  construction  work  should  be  carried  on  as  now,  except  where 
it  can  be  more  efficiently  and  economically  done  by  special  commissions,  boards,  de- 
partments or  bureaus. 

I.    AN  INTERSTATE  SUPERVISORY  COMMISSION 

The  supervisory  commission  should  be  established  by  acts  of  the  Legislatures  of 
New  York  and  New  Jersey,  these  acts  to  be  confirmed  by  Congress.  There  should  be 
a  sewerage  district  under  that  commission. 

The  most  desirable  limits  for  the  sewerage  district  would  include  a  territory  of 
about  700  square  miles  about  half  of  which  would  be  in  New  York  and  about  half  in 
New  Jersey.  Within  this  territory  there  was  in  1910  a  population  exceeding  6,000,000 
people.  At  the  rate  of  increase  which  has  been  maintained  for  some  years  the  popula- 
tion will  exceed  11,500,000  by  the  year  1940.  The  quantity  of  sewage  produced  in  1910 
was  abotit  765,000,000  gallons  per  24  hours  and  it  has  been  estimated  that  there  will 
be  over  1,700,000,000  gallons  produced  by  the  year  1940. 

Within  the  territory  proposed  for  a  metropolitan  sewerage  district  no  sewage  is 
disposed  of  at  the  present  time  without  producing  a  nuisance  or  serious  risk  of  nuis- 
ance. There  is  no  central  sanitary  control  over  the  discharge  of  sewage  by  the 
national  or  state  governments.  The  difficulties  to  be  overcome  in  disposing  of  sew- 
age are  of  unusual  difficulty  and  complexity  owing  to  the  great  extent  of  the  terri- 
tory, the  large  population  and  the  many  hydrographic,  sanitary  and  economic  ques- 
tions which  must  be  considered  in  the  localities  concerned. 

The  present  condition  of  the  harbor,  the  rapidly  increasing  quantities  of  sewage 
which  are  being  discharged  into  it  and  the  difficulty  and  cost  of  preventing  excessive 
pollution  make  it  evident  that  the  time  has  arrived  when  the  two  States  should  place 
the  protection  of  the  waters  against  sewage  in  the  hands  of  a  single  authority.  It  will 
be  regrettable  and  expensive,  not  to  say  dangerous,  if  the  existence  of  the  State 
boundary  line  which  runs  through  the  center  of  the  harbor  is  allowed  to  prevent  the 
centralization  of  proper  control  over  the  sewage  question. 


144  PLANS  FOR  THE  PROTECTION  OF  THE  HARBOR 

The  duties  of  an  interstate  sewerage  commission  for  the  metropolitan  district  of 
New  York  and  New  Jersey  should  be  to  require  the  construction  of  such  works  of 
main  drainage  as  are  needed  to  permanently  improve  and  protect  the  waters  of  New 
York  harbor  and  all  the  waters  within  the  metropolitan  sewerage  district.  The 
commission  should  not  be  charged  with  the  duty  of  constructing  local  sewerage,  main 
drainage  or  disposal  works,  but  should  have  advisory  authority  over  their  design  in 
so  far  as  they  may  affect  the  condition  of  the  harbor.  The  sewers  needed  for  the 
purely  local  purpose  of  carrying  the  sewage  from  the  houses  to  the  water  front  or 
other  point  for  discharge  should  be  designed  by  the  several  municipalities.  The 
main  drainage  or  arterial  sewerage  systems  needed  to  collect  the  sewage  from  the  local 
sewers  and  carry  it  to  the  central  points  for  disposal  should  be  designed  and  built  by 
the  several  municipalities  acting  conjointly,  or  by  district  sewerage  boards  created  for 
the  purpose  of  disposing  of  the  sewage  of  considerable  portions  of  the  metropolitan 
district.  Such  purification  works  and  outfalls  as  are  required  should  be  constructed 
by  these  sewer  authorities  or  the  district  sewerage  boards. 

The  central  board  having  jurisdiction  over  the  metropolitan  district  should  be 
composed  of  representatives  or  delegates  from  the  States  of  NeAV  York  and  New  Jersey 
and  the  United  States  Government.  The  duties  of  the  central  commission  should  be 
to  prepare  a  general  and  normal  standard  of  cleanness  for  the  natural  and  artificial 
water  courses  within  the  metropolitan  district,  including,  if  deemed  necessary,  special 
standards  for  different  places.  Standards  of  different  degrees  of  severity  for  the  dif- 
ferent parts  of  the  harbor  may  be  found  desirable,  depending  upon  the  uses  to  which 
the  water  is  put  and  according  to  the  quality  and  quantity  of  the  sewage  discharged, 
the  topographical  conditions  and  consequently  the  cost  to  the  municipalities  of  produc- 
ing an  effluent  of  good  quality.  From  a  comprehensive  standpoint  it  may  be  more 
economical  to  demand  compliance  with  a  very  high  standard  of  purity  for  the  sewage 
of  some  communities,  rather  than  with  a  uniform  standard  from  all  where,  for  ex- 
ample, the  local  circumstances  seem  to  justify  such  an  exception. 

There  should  be  considered  not  only  the  particular  part  of  the  harbor  where  the 
sewage  is  discharged,  but  those  other  parts  which  may  be  indirectly  affected.  There 
should  also  be  considered  the  total  quantity  of  sewage  produced  as  well  as  the  ratio 
which  the  sewage  bears  to  the  water  into  which  it  is  discharged,  and  account  should 
be  taken  of  the  possibility  that  objectionable  deposits  of  sludge  may  occur. 

The  central  commission  should  determine  where  discharges  of  sewage  may,  and 
may  not,  take  place  and  pass  upon  the  quality  of  the  discharging  sewage  liquor.  The 
central  commission  should  insist  upon  plans  being  furnished  by  cities  or  drainage 
boards  representing  parts  or  groups  of  municipalities  for  a  progressive  scheme  of  sew- 


FORM  OF  ADMINISTRATION  RECOMMENDED  145 

age  disposal  and  should  encourage  the  combination  of  cities  and  towns  in  the  forma 
tion  of  drainage  boards  when,  in  the  judgment  of  the  central  commission,  such  boards 
are  needed  in  order  to  make  and  carry  out  proper  plans  for  the  sanitary  conservancy 
of  the  harbor  waters. 

There  should  be  drawn  up  a  code  of  instructions  or  regulations  covering,  as  far 
as  may  be,  the  general  requirements  of  the  central  commission.  There  should  be  pre- 
pared standard  specifications  and  a  set  of  uniform  designs  with  the  object  of  making 
as  uniform  as  practicable  and  more  efficient  the  construction  and  maintenance  of 
sewers  and  other  appurtenances. 

The  central  authority  should  be  authorized  to  carry  on  such  experiments  and  in- 
vestigations as  may  be  necessary  in  order  to  increase  the  existing  knowledge  of  the 
principles  of  sewage  disposal  as  they  relate  to  the  metropolitan  territory.  It  should 
be  their  duty  to  make  such  studies  of  the  harbor  as  may  be  necessary  in  order  to 
form  an  authoritative  opinion  concerning  dangers  to  health  and  risk  of  nuisance. 

Power  should  be  given  to  the  central  commission  to  require  accurate  reports  to 
be  rendered  by  local  authorities  as  to  the  volume  and  quality  of  sewage  produced, 
progress  and  cost  of  sewerage  and  sewage  disposal  works,  value  of  property,  char- 
acter and  extent  of  the  industries  and  the  financial  status  of  the  municipalities. 

The  central  commission  should  have  power  to  enter  upon  all  lands  and  property 
in  the  district  at  any  time,  and  without  notice,  for  the  purpose  of  inspecting  the  local 
sewers,  main  drainage  and  disposal  works  and  the  sewage  and  for  taking  samples 
anywhere  and  in  any  part  or  parts  of  the  local  and  main  drainage  and  disposal 
works.  Authority  should  also  be  given  to  require  that  all  works  connected  with  the 
collection  and  disposal  of  the  sewage  be  so  bnilt  as  to  permit  samples  being  taken 
and  gaugings  of  the  flow  to  be  determined  except  in  those  cases  in  which  such  con- 
struction would  involve  unreasonable  cost.  The  central  commission  should  be  em- 
powered to  make  regulations  as  to  the  treatment  of  storm  water  as  well  as  sewage. 

The  central  commission  should  have  power  to  administer  oaths  and  subpoena  wit- 
nesses. It  should  be  their  duty  to  prepare  and  publish  reports  in  regard  to  the  prog- 
ress of  the  work  being  done  in  the  district  to  effect  a  sanitary  disposal  of  the  sewage 
together  with  a  statement  of  the  size  and  distribution  of  population,  the  condition  of 
health  and  the  sanitary  quality  of  the  harbor  waters. 

Also  it  should  be  the  duty  of  the  interstate  commission  to  require  the  employ- 
ment of  such  methods  of  sewage  disposal  as  will  reasonably  protect  New  York  harbor 
and  the  other  waters  in  the  metropolitan  district  against  excessive  sewage  pollution. 
This  duty  should  be  discharged  with  due  regard  to  expense  and  the  extent  and  nature 
of  the  existing  evils.   The  work  should  proceed  by  degrees.    The  central  commission 


146  PLANS  FOR  THE  PROTECTION  OF  THE  HARBOR 

should  deal  first  with  the  worst  offenders,  which  will  probably  be  found  to  be  the 
largest  cities  and  where  the  cost  of  substantial  improvement  will  be  least.  By  in- 
sisting upon  comprehensive  plans  for  sewage  disposal  being  made  at  an  early  day,  a 
program  of  sewer  building  which  can  be  carried  out  as  the  growth  of  population  and 
other  circumstances  require  will  be  adopted,  rather  than  definite  plans  for  immediate 
and  complete  construction. 

II.    A  CONSTRUCTING  COMMISSION  FOR  NEW  YORK 

With  respect  to  the  form  of  administration  which  should  have  charge  of  the  con- 
struction of  the  engineering  works  for  New  York,  the  following  recommendation  is 
made. 

The  works  should  be  built  by  a  special  commission.  The  sewage  problem  is  essen- 
tially one  problem  and  not  an  aggregation  of  more  or  less  loosely  related  parts.  The 
pollution  is  not  only  local  but  general,  and  the  system  which  is  to  correct  the  con- 
ditions should  be  one  general  system.  Such  divisions  of  the  work  as  are  necessary 
should  depend  chiefly  upon  topographical  conditions  and  the  facilities  which  the 
various  sections  of  the  harbor  afford  for  the  assimilation  of  sewage,  and  not  upon 
political  boundaries.  The  works  would  be  of  such  magnitude  that  they  should  receive 
the  concentrated  attention  of  a  special  board  or  commission. 

The  creation  or  designation  of  a  central  commission  to  construct  main  drainage 
and  sewage  disposal  works  would  be  in  accordance  with  precedent,  as  witness  the  pro- 
vision made  for  constructing  New  York  City's  water  supply  and  rapid  transit  systems, 
the  metropolitan  sewers  of  Boston  and  vicinity,  the  main  drainage  system  of  the 
London  County  Council,  the  drainage  and  disposal  works  of  Birmingham  and  neigh- 
boring municipalities,  the  sewage  and  drainage  works  of  the  Emscher  Valley  in  Ger- 
many, the  trunk  sewer  system  of  the  Passaic  Valley  in  New  Jersey  and  the  sewage 
disposal  works  of  Chicago. 

In  some  cases,  but  not  all,  the  main  drainage  commissions  are  temporary  in  char- 
acter and  when  the  work  for  which  they  have  been  created  is  completed,  they  go  out 
of  existence  and  the  result  of  their  labor  is  turned  over  to  some  permanent  and 
usually  pre-existing  department. 

For  a  special  commission  to  be  created  for  the  main  drainage  of  New  York, 
special  legislation  would  doubtless  have  to  be  secured  at  Albany.  This  legislation  could, 
with  advantage,  be  modeled  to  some  extent  upon  that  of  the  Catskill  Water  Board. 

The  work  of  constructing  the  main  drainage  works  required  for  New  York  could 
be  placed  in  the  hands  of  the  New  York  Water  Board,  the  powers  and  duties  of  that 


FORM  OF  ADMINISTRATION  RECOMMENDED  147 

body  being  appropriately  altered  by  legislative  act  for  that  purpose.  The  Water 
Board  has  a  large  engineering  and  clerical  organization.  It  is  nearing  the  comple- 
tion of  its  undertaking.  Its  engineering  works  have  been  hydraulic  in  character  and 
of  magnitude  commensurate  with  the  main  drainage  and  sewage  disposal  plants.  The 
Commission  is  already  in  existence  and  possesses  machinery  for  the  conduct  of  its 
affairs.  These  are  among  the  obvious  advantages  which  could  be  gained  by  placing  the 
main  drainage  works  in  the  hands  of  the  Water  Board  for  construction. 

If  the  works  were  built  by  a  central  commission,  that  commission  would  be  as 
responsible  and  responsive  to  one  section  of  the  city  as  to  another.  Security  in  this 
respect  would  not  depend  upon  harmony  and  co-operation,  as  it  would  if  the  construc- 
tion of  the  works  were  placed  in  the  hands  of  the  boroughs.  Being  for  the  benefit  of 
New  York  harbor  and  the  city  as  a  whole,  questions  of  local  interest  should  be  made 
subservient  to  those  of  the  general  welfare  and  this  could  best  be  secured  by  a  board 
composed  of  men  representing  the  city  at  large.  The  undivided  time  and  attention 
of  a  central  commission  being  given  to  the  subject  for  which  it  was  created,  there 
would  be  no  lapse  of  interest  or  lack  of  attention  to  the  work. 

Borough  construction,  however  appropriate  it  may  be  for  local  drainage,  the 
object  of  which  is  to  improve  the  city's  occupied  land,  is  not  so  suitable  for  main 
drainage  and  sewage  disposal  works  whose  purpose  it  is  to  improve  and  protect  the 
city  at  large  and  its  general  waterways.  Harbor  work  should  be,  and  generally  is, 
strongly  centralized,  as,  for  example,  dredging  and  dock  building. 

If  the  work  were  placed  in  the  hands  of  a  central  commission,  no  time  or  energy 
would  be  lost  in  overcoming  the  inertia  of  a  borough  whose  duty  it  was  to  construct 
works  chiefly  for  the  benefit  of  other  boroughs,  or  in  weighing  the  relative  merits  of 
rival  schemes  presented  by  the  several  boroughs  for  mutual  improvement,  or  passing 
judgment  upon  measures  intended  primarily  for  local  benefit. 

The  construction  of  a  main  drainage  and  sewage  disposal  system  requires  a  high 
degree  of  scientific  and  technical  skill.  A  central  commission  with  a  single  corps  of 
technical  assistants  would  be  less  expensive  for  the  city  to  maintain  than  a  separate 
corps  in  each  borough.  The  experience  gained  in  constructing  and  operating  the 
works  in  one  locality  should  be  completely  available  for  the  benefit  of  all.  This  would 
be  automatically  provided  for  in  a  central  constructing  commission. 

In  arriving  at  a  conclusion  upon  the  subject  of  administration,  the  commission 
had  the  benefit  of  the  views  of  a  number  of  citizens  who,  from  official  position  or 
other  practical  experience,  are  particularly  well  qualified  to  advise.  The  number 
included  Ex-Mayors  Seth  Low  and  George  B.  McClellan,  also  Messrs.  Lawson  N. 


148  PLANS  FOR  THE  PROTECTION  OF  THE  HARBOR 

Purdy,  Robert  W.  DeForest,  Henry  R.  Towne,  E.  H.  Outerbridge,  Charles  Strauss 
and  George  L.  Rives. 

The  work  of  the  Metropolitan  Sewerage  Commission  throughout  has  been  based 
upon  the  theory  that  the  problem  of  disposing  of  New  York's  sewage  without  harm 
to  the  public  health  and  welfare  was  city-wide  in  scope,  demanding  comprehensive 
solution  and  strongly  centralized  control. 

It  is  the  opinion  of  the  Commission  that  the  construction  and  maintenance  of  the 
works  should  be  placed  in  the  hands  of  a  special  commission  existing  for  that  pur- 
pose. It  is  possible  that  where  parts  of  the  system  would  be  situated  wholly  within  a 
borough,  it  might  be  desirable  to  turn  those  parts  over  to  that  borough  to  operate 
under  the  regulation  and  control  of  the  central  commission. 

If  a  commission  were  created  to  construct  such  sewerage  works  as  New  York 
requires,  it  should  take  over  the  effects  of  the  Metropolitan  Sewerage  Commission, 
make  the  final  detailed  plans  and  estimates  required  and,  after  duly  submitting  its 
projects  to  the  Board  of  Estimate  for  approval,  proceed  with  the  construction. 

In  this  way  the  city  would  be  certain  to  obtain  the  benefit  of  such  works  as  would 
be  needed  and  without  unnecessary  loss  of  time  or  expenditure  of  money. 

There  would  be  no  delay  for  investigations  of  an  academic  or  unnecessary  char- 
acter. The  city  would  be  protected  against  the  extravagance  of  building  works  long 
before  or  long  after  they  were  needed. 

The  detailed  planning  being  in  the  hands  of  the  constructive  body,  responsibility 
for  obtaining  practical  results  at  a  minimum  of  expenditure  would  be  concentrated. 

In  preparing  a  bill  for  the  new  commission,  it  will  be  desirable  to  be  guided  by 
Chapter  724  of  the  Laws  of  1906,  which  is  the  basic  legislation  for  the  Catskill  Water 
Board.  That  act  covers  much  of  the  material  which  will  be  required  on  the  organ- 
ization of  an  independent  board  of  main  drainage  and  sewage  disposal  and  hence  fur- 
nishes material  which,  having  been  tested,  may  safely  be  followed.  It  also  furnishes 
much  which  by  a  similar  test  it  would  be  wise  to  avoid.  General  heads  for  the  bill 
follow : 

1.  Take  over,  continue  and  extend  the  work  of  the  Metropolitan  Sewerage  Com- 
mission. 

2.  Make  such  detailed  investigations,  including  surveys  and  borings,  as  may  be 
necessary  to  make  contract  plans  and  estimates  for  the  construction  of  a  system  of 
main  drainage  and  sewage  disposal  for  New  York  City. 

3.  Prepare  the  necessary  plans  and  estimates. 

4.  Construct  the  main  drainage  and  sewage  disposal  works  required  after  they 
have  been  duly  approved  by  the  Board  of  Estimate  and  Apportionment. 


FORM  OF  ADMINISTRATION  RECOMMENDED 


149 


5.  Operate  the  works  after  construction  or,  where  parts  are  situated  wholly  within 
a  borough,  perhaps  turn  those  parts  over  to  that  borough  to  operate  under  the  regu- 
lation and  control  of  the  central  commission. 

6.  The  commission  should  be  appointed  by  the  Mayor  and  report  to  him. 

7.  Authority  should  be  given  for  the  employment  of  an  engineering  and  clerical 
force  and  such  other  assistants  as  may  be  necessary  for  the  performance  of  the  duties 
specified. 

8.  Appropriations  for  the  work  to  be  done  should  be  made  by  the  Board  of  Esti- 
mate and  Apportionment  in  accordance  with  provisions  of  the  Catskill  Water  Board. 

!>.  The  cooperation  and  assistance  of  the  Sewer  Bureaus  of  the  city  should  be 
given  as,  and  when,  requested  by  the  new  commission. 

10.  The  work  of  the  new  commission  should  not  overlap  that  of  the  Sewer  Bureaus 
as  provided  by  the  city  charter  except  where  unavoidable  in  providing  for  the  main 
drainage  and  disposal  of  the  city's  sewage. 

11.  Corporate  stock  of  the  City  of  New  York  should  be  authorized  to  be  issued 
by  the  Board  of  Estimate  and  Apportionment  without  the  concurrence  or  approval  of 
any  other  board  or  public  body,  in  accordance  with  section  one  hundred  and  sixty- 
nine  of  the  Greater  New  York  Charter,  in  order  to  provide  the  means  for  carrying  out 
the  provisions  of  this  act.  All  payments  from  the  sale  of  such  corporate  stock  should 
be  made  upon  proper  vouchers  in  accordance  with  the  laws  and  regulations  now  in 
force  for  the  payment  of  money  by  the  Comptroller  of  the  City  of  New  York. 

12.  Authority  should  be  given  for  the  acquirement  of  such  property  as  may  be 
needed  for  the  construction  of  the  main  drainage  and  disposal  works  after  due  and 
proper  authorization  has  been  given. 


150  PLANS  FOR  THE  PROTECTION  OF  THE  HARBOR 


PLATE  X 

Order  in  which  it  is  suggested  that  the  works  be  built 


PART  III 

Reports  of  Experts  Consulted  by  the  Commission 


PART  III 

Reports  of  Experts  Consulted  by  the  Commission 


CHAPTER  I 

CRITICAL  REPORTS  ON  THE  COMMISSION'S  WORK  WITH  SPECIAL 
REFERENCE  TO  THE  MAIN  DRAINAGE  SYSTEM  PROPOSED 
FOR  THE  PROTECTION  OF  THE  LOWER  EAST  RIVER 
AND  OPINION  OF  THE  COMMISSION  WITH 
RESPECT  TO  THESE  REPORTS 

I 

INTRODUCTORY 

Of  the  five  experts  whose  reports  are  here  published,  all  are  in  agreement  with  the 
Commission  in  the  opinion  that  main  drainage  and  sewage  disposal  works  are  required 
for  the  protection  of  the  Lower  East  river  and  that  the  time  has  come  to  begin  their 
construction. 

Three  of  the  five  are  convinced  that  nothing  short  of  the  removal  of  a  large  part 
of  the  sewage  naturally  tributary  to  this  part  of  the  harbor  will  produce  the  improve- 
ment needed;  the  other  two  consider  that  partial  purification  and  local  discharge  will 
be  sufficient,  at  least  for  many  years. 

The  Commission's  opinion  is  that  the  removal  of  not  less  than  200  million  gallons 
of  sewage  per  twenty-four  hours  to  an  ocean  outlet  is  a  project  to  which  the  city  should 
look  forward  as  an  early  necessity  and  it  has  provided  general  plans  and  estimates  to 
accomplish  this  result.  The  Commission  recommends  that  the  ocean  island  project  be 
carried  out  in  progressive  stages,  the  first  of  which  would  be  the  collection  of  the 
sewage  to  a  number  of  central  points  for  screening  and  local  discharge  through  sub- 
merged outlets.  If  experience  shows  this  method  of  disposal  to  be  insufficient,  the 
local  outlets  would  be  discontinued  and  the  sewage  would  be  carried  to  sea.  With 
this  method  of  procedure,  the  Commission  and  its  advisers  are  in  complete  accord. 

The  reports  are  so  important  that  the  Commission  publishes  them  here  in  full. 
To  facilitate  an  understanding  of  the  principal  subjects  dealt  with,  particularly  the 
oxygen  standard  and  the  project  for  the  relief  of  the  Lower  East  river,  it  has  seemed 
desirable  for  the  Commission  to  preface  the  reports  with  an  introductory  note,  a  digest 
of  the  reports  and  the  Commission's  opinion  upon  the  main  points  which  the  experts 
have  discussed. 


154 


REPORTS  OF  EXPERTS 


The  Oxygen  Question 

All  who  possess  an  adequate  and  unprejudiced  knowledge  of  the  harbor  recog- 
nize that  (1)  the  water  is  now  inadmissibly  polluted,  and  is  especially  foul  in  some 
locations;  (2)  extensive  works  of  main  drainage  and  sewage  disposal  are  required 
in  order  to  improve  and  permamently  protect  the  harbor;  (3)  the  construction  of  the 
necessary  works  should  be  placed  in  the  hands  of  a  central  constructing  body;  (4) 
the  system  of  main  drainage  and  sewage  disposal  which  the  city  requires  should  be 
begun  at  once  and  added  to  gradually  as  their  necessity  is  recognized;  (5)  the  prin- 
ciple of  development  should  apply  not  only  to  the  gradual  extension  of  the  collecting 
system,  but  to  the  efficiency  of  the  method  of  disposal;  (6)  the  requirements  of  the 
future  will  be  more  exacting  than  those  of  the  present  in  regard  to  the  degree  of 
cleanness  which  should  be  maintained  in  the  waterways;  (7)  the  increasing  quan- 
tities of  sewage  will  make  the  realization  of  any  standard  increasingly  difficult,  and 
(8)  in  disposing  of  the  sewage  the  digestive  capacity  of  the  water  for  sewage  matters 
should  be  utilized  to  the  fullest  extent  compatible  with  a  due  regard  to  the  public 
health  and  welfare. 

In  the  Commission's  opinion  it  is  not  indispensable  that  any  pronouncement  as  to 
oxygen  should  be  made  in  the  standard  of  cleanness,  since,  if  the  remaining  specifica- 
tions of  the  standard  are  faithfully  carried  out,  there  will  be  enough  oxygen  in  the 
water  to  meet  all  reasonable  requirements.  A  limit  to  the  exhaustion  of  the  oxygen  is 
desirable  merely  as  an  amplification  of  the  other  specifications  of  the  standard.  The 
oxygen  which  exists  in  dissolved  form  in  the  water  is  a  convenient  measure  of  the  rela- 
tive intensity  of  pollution  and  nothing  more.  It  is  superior  to  other  measures  of  pollu- 
tion in  that  it  is  definite  and  can  readily  be  made  and  interpreted.  Resting  upon  ac- 
curate analysis,  it  is  independent  of  such  sources  of  error  as  are  inseparable  from  tests 
which  depend  upon  personal  judgment.  It  is  not  practicable  to  describe  the  appear- 
ance or  odors  of  pollution  with  anywhere  near  the  accuracy  with  which  the  amount  of 
dissolved  oxygen  can  be  expressed. 

With  reference  to  its  definiteness  and  adequacy,  the  oxygen  test  is  probably 
the  best  chemical  criterion  to  be  found.  It  has  been  used  by  the  Commission  al- 
most to  the  exclusion  of  the  far  more  elaborate  and  difficult  determinations  of 
nitrogen  which  were  formerly  considered  to  be  indispensable  as  a  means  of  accurately 
measuring  the  extent  to  which  a  natural  body  of  water  was  polluted.  It  has  recently 
come  into  favor  with  other  investigators,  a  notable  example  of  its  value  being  afforded 
in  the  Eighth  Report  of  the  Royal  Commission  on  Sewage  Disposal  of  Great  Britain, 
issued  in  1913.  But  the  importance  of  the  oxygen  test,  like  any  other  measure,  de- 
pends upon  its  application;  and  since  experience  now  shows  that  it  may  be  misunder- 
stood, even  by  experts,  it  may  be  omitted. 


INTRODUCTION  155 

Omitting  the  reference  to  oxygen,*  the  Commission's  standard  of  cleanness  is  as 
follows : 

1.  Garbage,  offal  or  solid  matter  recognizable  as  of  sewage  origin  shall  not  be 
visible  in  any  of  the  harbor  waters. 

2.  Marked  discoloration  or  turbidity,  effervescence,  oily  sleek,  odor  or  deposits, 
due  to  sewage  or  trade  wastes,  shall  not  occur  except  perhaps  in  the  immediate 
vicinity  of  sewer  outfalls,  and  then  only  to  such  an  extent  and  in  such  places  as  may 
be  permitted  by  the  authority  having  jurisdiction  over  the  sanitary  condition  of  the 
harbor. 

3.  The  discharge  of  sewage  shall  not  materially  contribute  to  the  formation  of 
deposits  injurious  to  health  or  navigation. 

4.  The  quality  of  the  water  at  points  suitable  for  bathing  and  oyster  culture 
should  conform  substantially  as  to  bacterial  purity  to  a  drinking  water  standard.  It 
is  not  practicable  to  maintain  so  high  a  standard  in  any  part  of  the  harbor  north  of 
the  Narrows,  or  in  the  Arthur  Kill. 

Project  for  the  Protection  of  the  Lower  East  River 

It  is  proposed  to  carry  about  200  million  gallons  of  sewage  from  those  parts 
of  Manhattan  and  Brooklyn  which  are  naturally  tributary  to  the  Lower  East 
river  to  an  island  to  be  built  in  the  ocean  about  3  miles  from  shore.  The  rest  of  the 
sewage  tributary  to  the  Lower  East  river  and  that  naturally  flowing  to  the  Upper  bay 
and  the  Hudson  would  be  passed  through  grit  chambers  and  screens  and  discharged 
at  the  bottom  of  the  neighboring  channels  well  out  from  shore. 

The  ocean  island  project  would  collect  the  sewage  by  intercepting  sewers  run- 
ning along  the  water-front  and  passing  by  a  siphon  from  Manhattan  to  a  point  near 
the  Brooklyn  Navy  Yard.  A  pumping  station  would  force  the  sewage  through  a 
tunnel  to  the  island  where,  after  passing  through  settling  basins,  the  sewage  would 
be  discharged  into  the  surrounding  water  under  such  circumstances  as  would  insure 
prompt  diffusion  and  digestion.  The  Commission's  preliminary  studies  indicate 
that  the  total  cost  of  construction  for  the  ocean  island  outlet  would  be  about  $21,- 
466,000,  including  $4,072,000  for  the  Jamaica  bay  division.  The  fixed  charges  would 
be  about  $1,086,000,  allowing  $206,000  for  the  Jamaica  bay  division.  The  total  main- 
tenance and  fixed  charges  were  estimated  at  $1,598,000,  including  $286,000,  charge- 
able to  the  Jamaica  bay  division.  The  construction  of  the  island  has  been  estimated 
at  $615,000. 

*  Except  in  the  immediate  vicinity  of  docks  and  piers  and  sewer  outfalls,  the  dissolved  oxygen  in  the  water 
shall  not  fall  below  3.0  cubic  centimeters  per  liter  of  water.  (With  60  per  cent,  of  sea  water  and  40  per  cent,  of  land 
water  and  at  the  extreme  summer  temperature  of  80  degrees  F.,  3.0  cubic  centimeters  of  oxygen  per  liter  corresponds 
to  58  per  cent,  of  saturation.)  Near  docks  and  piers  there  should  always  be  sufficient  oxygen  in  the  water  to  prevent 
nuisance  from  odors. 


156  REPORTS  OF  EXPERTS 

Modifications  of  the  ocean  island  project,  as  first  proposed,  have  shown  the  possi- 
bility of  materially  reducing  the  cost  without  impairing  the  effectiveness  of  the  scheme 
of  protection  for  the  Lower  East  river.  In  accordance  with  these  modifications,  a  large 
amount  of  storm  water  originally  provided  for  would  be  excluded  from  the  works  and 
provision  would  not  he  made  for  receiving  the  Jamaica  bay  sewage.  The  sizes  of  the 
interceptors  and  tunnel  and  of  the  settling  basins  would  thus  be  reduced  and  the  cost 
could  be  cut  down  to  about  f 14,000,000,  and  the  yearly  cost  to  about  $1,000,000.  If  it 
were  thought  desirable  to  build  the  works  piecemeal,  it  would  be  feasible  to  construct 
the  interceptors  and  carry  the  sewage  to  the  two  centrally  located  points  on  the 
Lower  East  river  which  would  ultimately  be  connected  by  an  inverted  siphon.  Here 
screens  could  be  employed  until  such  time  as  the  need  of  entirely  removing  the  sewage 
from  the  Lower  East  river  territory  became  recognized.  After  passing  through  the 
screens,  the  sewage  would  be  discharged  into  the  water  of  the  Lower  East  river.  When 
it  became  necessary  to  complete  the  scheme,  there  would  be  left  for  construction  the 
inverted  siphon  between  Manhattan  and  Brooklyn,  the  pumping  station  to  force  the 
sewage  to  the  ocean,  the  force  main  and  the  island.  Reduced  to  these  lowest  terms  in 
order  to  show  how  the  works  could  be  constructed  gradually,  the  first  cost  would  be 
$4,000,000. 

The  ocean  island  project  is  not  intended  to  relieve  the  Lower  East  river  of  all 
the  sewage  which  is  now  tributary  to  that  stream,  much  less  that  which  will  be  trib- 
utary in  the  future.  Its  object  is  merely  to  remove  a  sufficient  part  of  the  burden  of 
pollution  to  permit  the  water  to  assimilate  the  remainder  without  offense.  The  Com- 
mission's island  project  applies  to  only  six  of  the  fifteen  sub-divisions  of  Manhattan 
and  Brooklyn  which  are  tributary  to  the  Lower  East  river.  These  six  produce  203 
of  the  288  million  gallons  of  sewage  which  it  is  estimated  is  now  (1914)  flowing  into  the 
East  river  between  Hell  Gate  and  the  Battery-  By  the  year  1960  the  total  quantity 
of  sewage  entering  will  be  at  least  500  million  gallons  per  day  and  at  that  time  the 
ocean  island  project,  if  in  operation,  will  be  taking  less  than  one-half  of  the  total 
contribution. 

In  addition,  there  will  be  discharged  from  the  Wards  Island  works  or,  if  these 
are  not  built,  from  some  part  of  the  Harlem  territory  302  million  gallons  of  sewage 
per  day  by  the  year  1960.  Therefore,  if  the  ocean  island  is  built,  there  will  be  dis- 
charged into  the  Lower  East  river  the  sewage  just  referred  to  as  the  Wards  Island 
effluent,  amounting  to  302  million  gallous  and  the  effluent  which  can  receive  no  more 
than  screening  from  the  rest  of  the  East  river  parts  of  Manhattan  and  Brooklyn,  215 
million  gallons  in  1960,  amounting  to  upwards  of  500  million  gallons  per  day. 

The  ocean  island  plan  was  made  after  carefully  considering  a  number  of  alter- 


INTRODUCTION  157 

native  methods  of  disposal,  including  (1)  treatment  in  works  situated  on  the  shores 
of  the  territory  from  which  the  sewage  was  derived  and  the  subsequent  discharge  of 
the  effluent  into  the  adjacent  waters;  (2)  removal  to  Wards  Island  at  Hell  Gate  for 
treatment  and  discharge;  (3)  pumping  to  Staten  Island  and  treatment  at  that  point 
with  discharge  into  the  Arthur  Kill  or  by  means  of  a  tunnel  through  Staten  Island 
into  Lower  New  York  bay;  (4)  conveyance  through  a  force  main  to  Barren  Island, 
treatment  at  that  point  and  discharge  into  Rockaway  Inlet  or  into  the  ocean  off 
Rockaway  Point. 

For  that  part  of  the  sewage  which  is  naturally  tributary  to  the  Lower  East  river, 
Hudson  and  Bay  not  otherwise  provided  for,  the  Commission  recommends  screens  and 
grit  chambers  as  the  treatment  most  appropriate  before  discharge  at  the  bottom  of 
the  nearest  deep  tidal  currents.  The  exact  number  and  location  of  the  screening 
stations  would  depend  upon  local  detailed  surveys  and  other  information  which  it  has 
been  unnecessary  to  obtain  before  the  work  is  put  in  hand  for  construction.  Careful 
studies  have  been  made  of  all  typical  situations  which  show  the  essential  character  of 
the  work  to  be  done  and  the  difficulties  to  be  overcome.  It  is  estimated  that  the  first 
cost  of  a  grit  chamber  and  screening  plant  will  average  about  f 100,000,  and  the  annual 
charges  about  $5,000,  where  pumping  is  not  required.  The  total  number  of  stations 
would  probably  not  exceed  20. 

In  many  respects  the  making  of  plans  for  the  disposal  of  the  sewage  of  that  part 
of  New  York  draining  naturally  to  the  Lower  East  river  has  been  the  most 
difficult  part  of  the  Commission's  work.  The  large  volume  of  sewage  to  be  dealt 
with,  the  relatively  small  body  of  water  into  which  it  is  now  discharged,  the  necessity 
for  keeping  the  river  clean  enough  to  answer  the  requirements  of  the  heavy  shipping 
and  of  the  dense  population  situated  upon  the  shores  and  the  absence  of  suitable 
areas  of  low-priced  land  within  many  miles  have  made  the  preparation  of  a  plan  of 
sewage  disposal  for  this  territory  particularly  difficult. 

Instead  of  carrying  out  the  project  with  its  interceptors,  siphon,  pumping  station, 
main,  island  and  settling  basin  disposal  plant  as  one  undertaking,  the  Commission 
recommends  that  only  the  first  step  in  the  execution  of  this  comprehensive  plan  be 
undertaken  immediately. 

The  works  to  be  taken  in  hand  at  first  would  be,  for  Manhattan,  an  intercepting 
sewer  running  along  the  Manhattan  water  front  from  the  Battery  at  the  south  and 
26th  Street  at  the  north  to  a  point  near  Corlears  Hook,  where  a  screening  and  pumping 
station  would  be  located.  The  screens  would  operate  upon  the  most  efficient  principle 
for  fine  screens.  The  sewage,  after  screening,  would  be  discharged  well  out  from  shore 
at  the  bottom  of  the  river  through  multiple  outlets. 


158  REPORTS  OF  EXPERTS 

On  the  Brooklyn  side,  the  sewage  would  be  collected  by  an  interceptor  from 
Classon  Ave.  at  the  south  to  Newtown  Creek  at  the  north  to  a  point  near  South  5th 
Street,  where  it  would  be  passed  through  screens  like  those  on  the  Manhattan  side  of 
the  river  and  pumped  through  submerged  outfalls  lying  on  the  river  bottom  to  a  dis- 
tance sufficiently  far  from  shore  to  insure  immediate  and  thorough  diffusion. 

The  sewage  from  the  rest  of  the  Lower  East  river  territory  in  Manhattan  and 
Brooklyn  would  be  collected  for  screening  and  discharge  probably  to  as  many  points  as 
there  were  subdivisions  or  principal  drainage  areas.  If,  after  the  foregoing  works 
shall  have  been  carried  out,  it  be  found  necessary  to  afford  further  protection  to  the 
Lower  East  river,  the  city  could  proceed  to  construct  an  inverted  siphon  to  carry  the 
sewage  of  lower  Manhattan  beneath  the  East  river  to  the  Brooklyn  shore  where,  after 
joining  the  sewage  from  the  screening  plant  at  South  5th  Street,  it  would  be  pumped 
to  sea  by  means  of  pumps  and  a  force  main  to  be  constructed  for  this  purpose. 

In  this  stage  of  the  development  of  the  project,  the  sewage  would  be  discharged 
through  multiple  outlets  arranged  from  an  outlet  island.  The  sewage  would  have 
been  screened  and  perhaps  aerated  and  disinfected  before  arriving  at  the  island. 

In  the  final  development  of  the  project,  the  treatment  works,  presumably  consist- 
ing of  settling  basins,  would  be  built.  The  sewage  would  pass  through  the  settling 
basins  and  receive  such  additional  treatment  as  might  be  necessary  before  discharge. 

In  the  systematic  and  gradual  development  of  the  ocean  island  project  as  here 
indicated,  it  will  be  possible  for  the  city  to  proceed  without  large  expense  in  any  year 
and  to  test  by  actual  experience  the  necessity  for  each  step  before  it  is  taken.  In  case 
it  is  not  thought  necessary  to  proceed  in  this  deliberate  manner,  it  will  be  possible  to 
combine  the  two  last  stages  and  build  the  siphon  between  Manhattan  and  Brooklyn, 
the  pumping  station,  force  main  and  island  works  at  one  time. 

The  gradual  construction  of  the  outlet  island,  in  accordance  with  the  plan  here 
proposed,  would  make  it  unnecessary  to  sacrifice  any  considerable  part  of  the  works 
constructed  in  any  stage  by  reason  of  their  becoming  useless  in  the  succeeding  stages 
of  development. 

II 

SYNOPSIS  OF  THE  EXPERTS'  REPORTS 
Reports  of  Messrs.  Fowler  and  Watson 

Before  arriving  at  an  opinion  as  to  the  best  solution  of  the  Lower  East  river 
problem,  the  Commission  laid  its  alternative  schemes  before  two  prominent  and  un- 
prejudiced sewage  experts,  Dr.  Gilbert  J.  Fowler,  of  Manchester,  and  Mr.  John  D.  Wat- 


INTRODUCTION  159 

son,  of  Birmingham.  These  experts  were  requested  to  come  to  New  York  and  study 
the  data  which  had  been  collected  by  this  Commission,  remaining  long  enough  to  be- 
come personally  acquainted  with  the  situation  and  to  weigh  the  relative  merits  of  the 
alternative  plans  which  had  been  made.  They  came  to  America  separately  and  made 
their  studies  independently  of  one  another,  although  while  still  in  New  York  and  later 
in  England  they  met  and  exchanged  views.  Messrs.  Fowler  and  Watson  are  acknowl- 
edged leaders  in  the  science  and  art  of  sewage  disposal  and  are  known  throughout 
Europe  and  America  not  only  for  their  professional  attainments  in  this  field,  but  for 
their  broad  experience  and  sound  judgment  in  dealing  with  new  problems.  Each  has  a 
large  consulting  practice  and  has  repeatedly  been  called  beyond  the  confines  of  his 
country  to  furnish  advice  on  the  disposal  of  municipal  sewage. 

Dr.  Fowler,  a  chemist,  is  a  Doctor  of  Science,  Fellow  of  the  Institute  of  Chemistry, 
Fellow  of  the  Royal  Sanitary  Institute  of  Great  Britain  and  author  of  numerous 
reports,  papers  and  contributions  to  the  subject  of  sewage  purification.  He  has  been  a 
contributor  to  the  work  of  the  Royal  Commission  on  Sewage  Disposal,  whose  pub- 
lished researches  constitute  the  most  exhaustive  and  valuable  reference  works  on 
sewage  in  any  language.  The  disposal  works  of  Manchester,  England,  of  which  Dr. 
Fowler  is  chemist,  have  been  developed  under  his  direction  to  a  high  point  of  efficiency. 
These  works  include  screens,  settling  basins,  contact  beds,  sludge  storage  reservoirs  and 
steam  vessels  for  transporting  the  sludge  to  the  open  sea. 

Mr.  John  D.  Watson,  who  is  a  member  of  the  Institute  of  Civil  Engineers  of 
Great  Britain,  a  Fellow  of  the  Royal  Sanitary  Institute  and  President  of  the  Insti- 
tute of  Sanitary  Engineers,  is  a  consulting  engineer.  His  published  addresses  re- 
viewing the  status  of  sewage  disposal  methods  are  among  the  most  notable  papers 
which  have  appeared  upon  the  question.  Like  Dr.  Fowler,  he  has  been  identified 
with  the  work  of  the  Royal  Commission  on  Sewage  Disposal.  Mr.  Watson  is  the 
Chief  Engineer  of  the  Birmingham,  Tame  and  Rea  District  Drainage  Board 
and  in  this  capacity  has  charge  of  the  sewage  purification  works  for  Birmingham  and 
various  cities  in  its  vicinity,  works  which  are  as  large  and  efficient  as  any  of  their 
kind.  Originally  consisting  of  farm  lands,  where  the  sewage  was  taken  for  disposal  in 
.  the  hope  of  utilizing  its  manurial  properties,  the  Birmingham  works  have  been  rebuilt 
by  Mr.  Watson  in  accordance  with  modern  scientific  principles  and  include  settling 
basins,  sludge-digesting  tanks,  supplementary  settling  basins,  percolating  filters, 
screens  and  sludge-drying  beds. 

The  reports  of  Messrs.  Fowler  and  Watson,  therefore,  approach  the  subject  with 
peculiar  authority  and  from  the  separate  standpoints  of  the  chemist  and  the  engineer. 
Each  recognizes  the  necessity  of  stopping  the  existing  pollution  and  improving  the 


160 


KEPORTS  OF  EXPERTS 


harbor  without  loss  of  time  and  each  critically  discusses  the  extent  and  nature  of  the 
works  which  will  be  required.  In  each  the  conclusion  is  reached  that  a  large  part  of 
the  sewage  which  is  tributary  to  the  Lower  East  river  and  Harlem  should  be  collected 
in  intercepting  sewers  near  the  water  front  and  carried  by  a  tunnel  to  an  island  to  be 
constructed  in  the  sea  at  the  mouth  of  the  harbor,  there  to  be  discharged  after  enough 
of  the  impurities  have  been  removed  to  insure  that  no  nuisance  or  injury  to  health 
will  result  from  the  effluent.  This  project  was  described  by  the  Metropolitan  Sewer- 
age Commission  in  its  Preliminary  Report  VI,  issued  under  date  of  February,  1913.* 

The  standard  of  cleanness  proposed  by  the  Commission  in  its  report  of  August, 
1912,  was  approved  by  Dr.  Fowler  and  Mr.  Watson  as  a  guide  of  minimum  require- 
ments. Mr.  Watson,  like  most  of  the  other  sanitary  experts  who  have  been  called 
upon  to  advise  in  regard  to  this  standard,  would  have  the  harbor  waters  kept  cleaner 
than  the  Commission's  provisions  demand.  Dr.  Fowler  discusses  the  present  pollu- 
tion in  considerable  detail  and  gives  much  attention  to  the  need  of  cleanness  with 
respect  to  these  waters.  Both  experts  lay  emphasis  upon  the  fact  that  the  pollution 
has  reached  large  proportions  and  is  rapidly  increasing. 

The  opinion  is  expressed  by  both  experts  that  if  the  digestive  capacity  of  the  harbor 
for  sewage  is  not  to  become  overloaded  to  the  point  of  an  intense  general  nuisance,  it 
will  be  necessary  to  carry  a  large  part  of  the  sewage  away  for  disposal,  it  being,  in 
their  judgment,  beyond  the  range  of  practicability  to  purify  it  sufficiently  upon  the 
shores  of  the  territory  in  which  it  is  produced  to  permit  the  effluent  to  be  discharged 
into  the  neighboring  waters. 

It  is  pointed  out  that  sewage  works  possessing  high  efficiency  are  so  likely  to  pro- 
duce odors  and  nuisance  from  flies  that  it  is  desirable  to  avoid  the  construction  of  such 
works  within  the  city  limits.  For  this  reason  it  is  their  opinion  that  only  such  com- 
paratively crude  and  simple  processes  as  employ  settling  basins,  grit  chambers  and 
screens  should  be  considered  for  installation  on  the  shores  of  Manhattan  Island  and 
central  Brooklyn.  There  is  no  land  anywhere  within  the  limits  of  Greater  New  York 
upon  which  it  would  be  permissible  to  construct  works  capable  of  purifying  the  sewage 
tributary  to  the  Lower  East  river  and  Harlem  by  percolating  filters,  such  as  Mr. 
Watson  employs  at  Birmingham,  or  contact  beds,  like  those  Dr.  Fowler  uses  at  Man- 
chester, because  of  the  nuisance  which  would  result  from  the  works. 

After  discussing  the  alternatives,  Messrs.  Fowler  and  Watson  arrived  at  the  con- 
clusion that  the  proper  solution  of  the  problem  was  to  carry  the  sewage  naturally 
tributary  to  the  Lower  East  river,  and  eventually  that  tributary  to  the  Harlem,  to  an 
island  to  be  built  at  sea.  On  this  island  the  sewage  should  be  passed  through  settling 
basins  and  perhaps  treated  with  electrolyzed  sea  water,  in  accordance  with  a  method 

*See  also  Part  II,  Chap.  VI,  this  report. 


INTRODUCTION 


161 


with  which  the  Metropolitan  Sewerage  Commission  had  made  some  experiments.  The 
effluent  from  the  island  should  be  discharged  in  such  a  way  as  to  cause  it  to  be  thor- 
oughly mixed  with  large  quantities  of  fresh  sea  water  and  the  organic  matters  oxidized 
and  rendered  permanently  harmless  and  inert  by  natural  agencies. 

Neither  Dr.  Fowler  nor  Mr.  Watson  was  dissuaded  from  endorsing  this  project  on 
account  of  its  cost.  Their  opinion  was  that  the  money  for  such  sewage  works  as  are 
necessary  for  the  health,  welfare  and  reputation  of  the  port  would  be  forthcoming, 
when  once  their  necessity  was  understood.  It  is  pointed  out  in  the  reports  that  other 
cities,  and  among  them  many  small  places,  have  spent  much  more  per  capita  for  sewage 
disposal  than  would  be  required  here. 

Mr.  Watson's  report  gives  considerable  attention  to  the  form  of  administration 
which  is  best  suited  for  the  construction  and  maintenance  of  the  necessary  sewers  and 
disposal  works  and  his  experience  gives  him  special  qualifications  to  deal  with  this  sub- 
ject. He  recommends  that  a  commission  be  created  which  shall  have  charge  of  the 
building  and  maintenance  of  such  sewage  disposal  stations  as  are  necessary  for  New 
York  and,  in  this  suggestion,  Dr.  Fowler,  with  a  knowledge  of  the  details  of  the  recom- 
mendation and  familiar  with  the  experience  of  cities  and  towns,  concurs. 

Following  the  critical  reports  of  Messrs.  Fowler  and  Watson,  the  Commission  is- 
sued its  Preliminary  Report  VI,  in  which  the  project  of  the  ocean  island  was  described, 
together  with  a  considerable  part  of  the  argument  which  led  the  Commission  to 
suggest  this  as  a  most  desirable  plan  for  the  disposal  of  the  Lower  East  river  sewage. 
The  reports  of  the  two  experts  were  published  together  as  Preliminary  Report  VII  in 
February,  1913. 

Reports  op  Messes.  Fuller  and  Hering 

In  the  summer  of  1913,  the  Commission  called  upon  Mr.  George  W.  Fuller  to 
state  whether,  in  his  judgment,  the  art  of  sewage  treatment  had  reached  such  a  point 
of  development  as  to  warrant  New  York  City,  at  this  time,  in  adopting  a  general  plan 
and  policy  for  main  drainage  and  sewage  disposal. 

Mr.  Fuller  is  a  graduate  of  the  Massachusetts  Institute  of  Technology  and  was, 
for  some  years,  bacteriologist  in  charge  of  the  Lawrence  Experiment  Station  of  the 
Massachusetts  State  Board  of  Health,  where  extensive  experiments  in  sewage  and 
water  purification  have  been  carried  on  for  years.  He  has  been  the  sanitary  adviser 
of  many  cities  and  towns  in  the  United  States  in  regard  to  water  supplies  and  sewage 
disposal  works.  Mr.  Fuller  was  one  of  the  advisers  of  the  Passaic  Valley  Sewerage 
Commissioners  of  New  Jersey,  which  is  constructing  a  trunk  sewer  to  carry  the  sewage 
of  Paterson,  Newark  and  about  twenty  cities  and  towns  in  New  Jersey  with  an  esti- 
mated population  in  1940  of  1,649,000  inhabitants  to  Upper  New  York  bay  for  discharge. 


162  REPORTS  OF  EXPERTS 

In  July,  1913,  Mr.  Rudolph  Hering  of  New  York  was  engaged  by  the  Commission 
to  review  its  work,  the  ground  to  be  covered  being  the  necessity  and  sufficiency  of  the 
plans  which  the  Commission  was  preparing  for  the  disposal  of  New  York's  sewage. 
It  was  stated  that  this  study  should  consist  of  an  examination  of  the  Commission's 
reports  and  other  data  and  a  consideration  of  the  engineering  principles  upon  which 
the  plans  were  prepared. 

Mr.  Hering,  who  is  a  prominent  sanitary  engineer,  has  long  been  recognized  as  a 
leading  advocate  of  the  disposal  of  sewage  by  discharge  into  natural  bodies  of  water, 
where  this  can  be  done  without  harmful  consequences.  He  has  made  numerous  inves- 
tigations and  reports  on  the  disposal  of  the  sewage  of  cities.  For  some  years  Mr. 
Hering  was  the  engineer  of  the  Passaic  Valley  Sewerage  Commissioners  and  took  a 
prominent  part  in  preparing  their  plan  to  discharge  about  215,000,000  gallons  of  sewage 
per  day  into  New  York  harbor.  It  was  at  first  proposed  to  discharge  this  sewage  in  a 
crude  condition,  but  later  at  the  instance  of  the  United  States  Government  it  was 
agreed  that  the  sewage  should  first  be  passed  through  screens  and  settling  basins. 

The  reports  of  Messrs.  Fuller  and  Hering  are  similar  in  scope,  treatment  and  con- 
clusions. Each  report  proposes  that  the  Commission's  oxygen  standard  be  cut  in  half 
and  opposes  the  ocean  island  project  for  the  protection  of  the  Lower  East  river  and  in 
place  of  this  plan  recommends  partial  and  local  treatment  for  the  sewage  and  its  local 
discharge  into  the  harbor.* 

A  large  part  of  the  reports  of  Messrs.  Fuller  and  Hering  is  given  to  a  discussion 
of  the  oxygen  problem  as  it  relates  to  the  disposal  of  sewage  through  dilution  with 
the  harbor  waters. 

Mr.  Fuller  is  of  the  opinion  that  the  Commission's  oxygen  standard  of  a  minimum 
of  3  c.  c.  per  liter  of  water  which,  under  summer  conditions,  is  equivalent  to  about  58 
per  cent,  of  saturation  can  safely  be  reduced  by  one-half,  provided  that  sludge  is  not 
allowed  to  accumulate  to  such  an  extent  as  to  become  a  serious  factor  in  absorbing 
oxygen  from  the  water. 

Mr.  Hering  recommends  25  per  cent,  as  a  minimum  oxygen  standard  with  frequent 
sludge  removal.  Both  experts  hold  the  opinion  that  sludge  is  an  important  factor,  not 
only  in  exhausting  oxygen  from  the  water,  but  in  producing  nuisance  from  odors,  a  view 
which  the  Commission's  investigations  fully  justify. 

Elsewhere  in  this  report  (in  the  introductory  note  to  the  reports  of  the  experts) 
will  be  found  an  expression  of  the  Commission's  opinion  with  respect  to  the  oxygen 
.standard. 

*  As  has  been  stated  elsewhere,  the  reports  of  Messrs.  Fuller  and  Hering  have  been  supplemented  by  letters 
endorsing  the  Commission's  recommendation  that  the  city  proceed  with  the  gradual  construction  of  the  ocean  island 
project. 


INTRODUCTION 


163 


Mr.  Fuller  states  his  opinion  that  the  present  status  of  the  art  of  sewage  dis- 
posal and  the  developments  which  are  likely  to  be  made  in  future  warrant  the  adop- 
tion at  this  time  of  a  definite  policy  for  the  main  drainage  of  the  city.  Much  space  is 
given  to  a  restatement  of  the  Commission's  position  that  the  sewage  of  the  whole  city 
should  not  be  collected  to  a  single  point  for  disposal.  After  reviewing  the  various  forms 
in  which  this  idea  has  been  studied  and  the  Commission's  reasons  for  rejecting  it,*  Mr. 
Fuller  concurs  in  the  findings  of  the  Commission  on  this  proposition  in  all  its  phases. 

Mr.  Fuller  confirms  the  opinion  expressed  by  the  Commission  and  by  Messrs. 
Fowler,  Watson  and  Datesman  that  highly  efficient  purification  works,  such  as 
sprinkling  filters,  should  not  be  located  in  the  built-up  parts  of  the  city  because  of 
the  danger  that  offensive  odors  will  be  produced  by  them.  He  concurs  in  the  view 
of  the  Commission  that  the  digestive  capacity  of  the  harbor  for  sewage  should  be 
utilized  to  as  great  an  extent  as  is  compatible  with  a  due  regard  to  the  protection 
of  the  public  health  and  the  avoidance  of  nuisance.  He  agrees  that  the  sludge 
and  screenings  extracted  from  the  sewage  can  most  advantageously  be  disposed  of 
by  barging  to  sea  and  he  does  not  look  forward  to  the  probability  that  sewage  can 
profitably  be  utilized  in  the  near  future.  Two-story  tanks  of  the  Imhoff  type,  as 
compared  with  single-story  tanks  of  the  Dortmund  type,  are  not  justifiable,  in  his 
opinion,  when  the  comparative  cost  of  the  two  are  taken  into  consideration. 

In  discussing  processes  of  sewage  treatment,  Mr.  Fuller  lays  much  emphasis  upon 
dilution  and  here,  as  elsewhere  in  his  report,  the  discharge  of  sewage  into  natural 
bodies  of  water  under  proper  conditions  is  strongly  advocated  as  a  reliable  and  efficient 
method  of  disposal.  Aeration  is  described  as  a  promising  means  of  guarding  against 
the  putrefaction  of  sewage  before  treatment  or  discharge,  but,  except  for  limited  quan- 
tities of  unstable  organic  substances,  aeration  cannot  be  counted  upon  as  an  oxidizing 
agent.  Electrolytic  treatment  to  oxidize  sewage  seems  to  Mr.  Fuller  to  have  little 
value,  but  the  electric  production  of  a  coagulant  to  precipitate  colloidal  and  other  non- 
settling  organic  matters,  as  done  experimentally  in  the  Commission's  laboratory,  may 
be  of  considerable  use.  Fine  screens  can  remove  more  organic  matter  for  a  given  cost 
than  can  any  other  type  of  apparatus  and  the  limited  and  unsatisfactory  experience 
which  has  been  had  with  them  in  America  should  not  prejudice  one  against  their  more 
reliable  and  continuous  service  as  already  shown  in  Germany,  for  example.  The  best 
results  from  sedimentation  are  to  be  had  with  detention  periods  of  two  hours.  For 
New  York,  Mr.  Fuller  favors  single-story  tanks  with  hopper  bottoms,  such  as  the  Com- 
mission has  proposed  throughout  its  planning,  on  the  ground  that  it  is  undesirable  to 
septicize  the  sludge  near  its  points  of  origin.     As   compared   with   settling  basins, 

*See  Preliminary  Report  I,  issued  September,  1911. 


164  REPORTS  OF  EXPERTS 

screens  are  desirable  only  where  it  is  necessary  to  remove  relatively  large  sewage 
solids.  Mr.  Fuller  does  not  approve  of  chemical  precipitation  unless  in  exceptional 
cases  because  of  its  cost  and  the  difficulty  of  disposing  of  the  resulting  sludge. 

Mr.  Fuller  agrees  with  the  Commission  that  the  sewage  of  the  Lower  East  river 
territory  could  be  satisfactorily  disposed  of  by  diversion  to  an  artificial  island  at  sea, 
but  he  does  not  think  it  necessary  to  deal  with  it  in  this  manner.  Mr.  Fuller 
is  of  the  opinion  that  the  Lower  East  river  is  capable  of  absorbing  the  sewage 
from  the  populations  tributary  to  it  for  a  great  many  years  to  come,  providing 
the  sewage  is  first  screened  or  settled.  He  thinks  that  screens  and  sedimentation  basins 
can  be  expected  to  be  unobjectionable  to  public  sentiment  in  the  territory  naturally 
tributary  to  the  Lower  East  river  and  on  the  shores  of  the  Hudson  river.  If,  at  some 
future  time,  it  should  prove  desirable  to  divert  some  of  the  sewage  from  the  Lower 
East  river  region  to  some  point  such  as  the  outlet  island,  such  partial  diversion  can 
then,  in  his  opinion,  be  more  economically  affected  than  the  removal  of  the  sewage  now. 

The  Commission's  projects,  with  one  exception,  have  received  Mr.  Hering's  endorse- 
ment. He  expresses  himself  as  fully  in  accord  with  the  view  that  the  water  of  the  Hudson 
will  be  capable  of  assimilating  the  sewage  produced  on  the  west  side  of  Manhattan  Island 
after  the  sewage  is  passed  through  grit  chambers  and  screens  and  so  discharged  into 
the  water  as  to  insure  prompt  diffusion.  He  is  heartily  in  accord  with  the  proposition 
that  the  sewage  be  delivered  as  nearly  as  possible  into  the  channel  currents  by  means 
of  submerged  pipes  having  a  number  of  openings  discharging  as  nearly  horizontal  as 
practicable. 

With  regard  to  the  Commission's  projects  for  the  Upper  East  River  and  Harlem 
Division,  Mr.  Hering  has  only  favorable  comment  to  make.  He  approves  of  the  sep- 
aration of  the  total  area  of  the  division  into  five  subdivisions,  so  that  the  best  conditions 
for  collection  and  disposal  can  be  secured.  He  considers  that  the  proposed  outfalls  and 
disposal  works  are  all  well  located.  He  says  the  Commission  has  quite  properly  recom- 
mended screening  and  detention  of  the  floating  matter  at  all  the  outfalls.  He  expresses 
the  opinion  that  sufficient  land  should  soon  be  secured  in  every  case  where  plants  will 
be  required  in  future. 

With  reference  to  Jamaica  bay,  Mr.  Hering  agrees  with  the  Commission  that  the 
location  of  Barren  Island  is  well  adapted  for  the  final  disposal  of  the  sewage  of  the 
western  part  of  Jamaica  bay,  including  whatever  treatment  may  be  necessary.  This 
point  of  discharge  is,  in  his  view,  the  best  one  now  available,  insuring,  as  it  does,  a 
sufficient  dispersion  and  high  dilution  of  the  tank  effluents.  In  Mr.  Hering's  opinion, 
at  no  time  in  the  future  will  objectionable  results  appear  from  these  works  either  in 


INTRODUCTION  165 

Jamaica  bay  or  along  the  beaches  of  Coney  Island  or  Roekaway.  If  the  outfall  island 
is  bnilt  for  the  relief  of  the  Lower  East  river,  Mr.  Hering  thinks  that  the  western 
branch  of  the  Jamaica  bay  intercepting  sewer  proposed  by  the  Commission  should  be 
connected  with  the  island  instead  of  with  works  to  be  built  at  Barren  Island. 

The  works  proposed  for  Jo  Cos  Marsh  are  also  approved.  Mr.  Hering  mentions, 
without  preference,  the  alternative  plan  of  settling  the  sewage  of  the  eastern  part  of 
Jamaica  bay  and  subsequently  discharging  it  into  the  ocean  at  a  point  about  4,000  feet 
from  shore.  In  his  opinion,  no  floating  matter  would  drift  toward  the  shore  and  no 
depositing  matter  would  interfere  with  navigation  or  drift  to  the  land. 

Mr.  Hering  considers  that  the  disposal  of  the  sewage  from  Richmond  offers  few 
difficulties  and  he  approves  of  the  Commission's  suggestions  for  separating  the  bor- 
ough into  subdivisions  and  collecting  the  sewage  of  each  one  separately  for  disposal 
at  economical  points  after  sufficient  treatment  has  been  given  it  to  keep  out  of  the 
water  all  floating  matter  and  sludge.  With  the  expectation  that  more  thorough  treat- 
ment may  be  necessary,  Mr.  Hering  suggests  that  the  works  be  so  designed  that  they 
will  permit  additions  to  be  made  in  case  more  complete  treatment  is  found  necessary 
in  the  future. 

In  regard  to  the  final  disposal  of  sludge,  Mr.  Hering  is  of  opinion  that  where 
settling  basins  will  be  required,  it  will  be  cheaper  to  take  the  sludge  out  to  sea  than 
to  dispose  of  it  near-by,  unless  the  sludge  is  of  an  inoffensive  kind. 

The  project  which  the  Commission  recommended  in  its  Preliminary  Report  VI 
for  the  construction  of  an  outlet  island  for  the  relief  of  the  Lower  East  river  does  not 
receive  Mr.  Hering's  unqualified  approval  for  the  reason  that  he  considers  the  cost  of 
construction  and  operation  larger  and  the  degree  of  improvement  higher  than  he  thinks 
the  circumstances  require.  As  stated  in  his  letter  supplementing  his  report,  he  favors 
the  gradual  construction  of  the  outlet  island  project,  as  the  Commission  has  proposed. 

Report  of  Mr.  George  E.  Datesman 

In  the  summer  of  1913,  the  City  of  Philadelphia,  which  had  been  studying  the 
problem  of  sewage  disposal  for  some  years,  sent  Mr.  George  E.  Datesman,  Principal 
Assistant  Engineer  of  its  Bureau  of  Surveys,  to  Europe  to  make  a  study  of  the  main 
drainage  and  sewage  disposal  works  of  foreign  cities.  The  scope  of  Mr.  Datesman's 
inquiry  included  systems  of  collection,  methods  and  materials  of  construction,  com- 
parison of  screening  and  settling  devices,  ratios  of  dilution,  conditions  governing  the 
adoption  of  a  system  of  disposal,  results  obtained  by  different  systems,  economies  and 
cost  data.    The  countries  visited  were  Germany,  France,  Belgium  and  England. 

In  view  of  the  fact  that  the  New  York  and  Philadelphia  conditions  were  somewhat 


166 


REPORTS  OP  EXPERTS 


alike,  the  Metropolitan  Sewerage  Commission  obtained  permission  from  Mr.  Morris  L. 
Cooke,  Director  of  the  Department  of  Public  Works,  and  Mr.  George  S.  Webster,  Chief 
Engineer  and  Surveyor,  of  Philadelphia,  for  Mr.  Datesman  to  come  to  New  York  and 
make  a  critical  examination  and  report  on  the  Commission's  studies  of  the  Lower  East 
river  problem  from  the  standpoint  of  his  Philadelphia  and  European  investigations. 

Mr.  Datesman  is  a  graduate  of  the  Engineering  Department  of  Lafayette  College 
and  a  member  of  the  American  Society  of  Civil  Engineers.  He  has  been  with  the 
Bureau  of  Surveys,  which  is  the  central  engineering  department  of  Philadelphia,  for 
twenty-six  years,  filling  positions  from  Draftsman  to  Acting  Chief  Engineer.  He  has 
had  charge,  under  the  Chief  Engineer,  of  sewer  design,  construction,  port  improvement, 
including  dredging  and  pier  construction,  wharf  and  bulkhead  work,  and  of  city  plan- 
ning. Mr.  Datesman  has  supervised  the  studies  and  plans  for  the  collection,  treatment 
and  disposal  of  the  sewage  of  Philadelphia  from  1908  to  the  present  date. 

Various  methods  of  treating  the  sewage  locally  before  discharging  it  into  the 
harbor  waters  are  considered  by  Mr.  Datesman  in  his  report  to  the  Metropolitan 
Sewerage  Commission,  with  the  result  that  settling  basins,  screens  and  grit  chambers 
appear  to  him  to  afford  the  only  means  worthy  of  careful  study.  The  large  areas  of 
land  required  and  the  certainty  of  nuisance  lead  him  to  exclude  other  and  more  efficient 
processes,  such  as  percolating  niters. 

The  practicability  of  constructing  settling  basins  in  various  situations  in  the 
built-up  sections  of  Manhattan  and  Brooklyn  and  on  islands  in  the  inner  harbor  is 
dealt  with  and  the  principal  arguments  in  favor  and  in  opposition  to  these  projects 
are  set  forth  by  Mr.  Datesman.  It  is  his  opinion  that  settling  basins  should  not  be 
built  beneath  the  city  streets  nor  on  property  acquired  for  the  purpose  in  the  built-up 
sections  of  the  city,  because  of  the  large  extent  of  such  works,  gases  produced,  cost 
as  compared  to  their  efficiency  and  the  popular  prejudice  toward  them  which  he  feels 
sure  would  be  aroused  in  their  neighborhood. 

The  efficiency  of  settling  basins  and  such  screens  as  can  be  used  in  New  York  is 
regarded  by  Mr.  Datesman  as  less  than  is  commonly  supposed,  his  point  of  view  being 
concerned  largely  with  the  dissolved  oxygen  in  the  water  and  with  deposits. 

After  considering  the  alternatives,  Mr.  Datesman  expresses  the  opinion  that  the 
Commission's  outlet  island  project  affords  the  proper  solution  of  the  Lower  East  river 
problem.  Like  the  Commission,  he  is  willing  to  have  his  project  carried  out  in  pro- 
gressive stages,  feeling  confident  that  time  will  show  the  necessity  for  the  entire 
scheme. 

Mr.  Datesman  agrees  with  Messrs.  Watson  and  Fowler  in  thinking  that  some  of 
the  Wards  Island  sewage  will  have  to  be  taken  to  the  ocean  outlet  in  course  of  time. 


INTRODUCTION  167 

The  experience  of  London,  Paris,  Berlin  and  other  cities  is  cited  to  show  that 
ample  precedent  exists  for  conveying  sewage  as  far  away  as  the  Commission  advises 
that  the  sewage  of  the  Lower  East  river  be  taken. 

Attention  is  called  by  Mr.  Datesman  to  a  marked  difference  between  American 
and  European  practice  in  connecting  the  outlets  of  local  sewerage  systems  to  the  in- 
terceptors used  in  main  drainage  works.  Whereas  American  engineers  run  their  in- 
terceptors beneath  the  local  sewers  and  discharge  the  storm  overflows  through  outlets 
which  are  virtually  extensions  of  the  local  sewer  outlets,  in  Europe  the  interceptors 
are  run  across  the  mouths  of  the  local  sewers  to  take  in  all  the  flow  and  discharge  the 
storm  excess  from  side  outlets  situated  at  conveniently  located  points.  The  European 
custom  leads  to  larger  interceptors  with  flatter  grades  and  this  results  in  a  consider- 
able saving  in  head  and  the  avoidance  of  regulators  possessing  many  moving  parts. 
These  are  substantial  advantages  over  what  has  heretofore  been  considered  good  prac- 
tice in  America,  and  the  Commission  has  given  careful  attention  to  the  design  of  in- 
terceptors in  the  manner  which  Mr.  Datesman  suggests. 

Ill 

THE  COMMISSION'S  OPINION  WITH  REGARD  TO  THE  EXPERTS'  REPORTS 

While  Messrs.  Fowler,  Watson  and  Datesman  would  have  construction  work 
started  at  once,  in  accordance  with  a  comprehensive  plan  which  would  begin  by  giving 
a  large  measure  of  improvement  to  the  waterways  in  the  center  of  the  city  and,  by  ad- 
ditions and  extensions,  provide  greater  benefit  in  the  course  of  a  generation  or  more, 
as  both  the  desire  and  need  of  improvement  increase,  Messrs.  Fuller  and  Hering  would 
be  content  with  a  scheme  which  would  serve  the  immediate  needs  and  postpone  the 
construction  of  a  complete  system  indefinitely.  Nothing  less  than  a  removal  to  sea 
of  all  the  Lower  East  river  and  Harlem  river  sewage  will  be  sufficient  in  the  distant 
future,  according  to  Messrs.  Fowler,  Watsou  and  Datesman,  and  they  think  the  present 
is  none  too  soon  to  provide  for  the  works  which  will  ultimately  be  necessary.  Their 
idea  is  that  the  works  should  be  built  gradually  so  that  it  would  be  possible  to  stop  the 
construction  at  any  time  when  the  needs  of  the  situation  were  met. 

Messrs.  Fuller  and  Hering  are  confident  that  local  and  partial  treatment  will 
always  be  sufficient  to  fit  the  sewage  for  discharge  into  the  city's  waterways.  The 
methods  which  Mr.  Fuller  considers  suitable  for  local  treatment  are  screens  and  set- 
tling basins.  Where  necessary,  the  final  discharge  would  be  through  submerged  out- 
lets. Mr.  Hering  advocates  "floatation  chambers,"  screens,  settling  basins,  coarse- 
grained filters  (by  which  he  means  the  more  commonly  called  sprinkling  filters)  and 


168  REPORTS  OF  EXPERTS 

submerged  outlets.  The  probability  of  nuisance  from  sprinkling  filters,  if  constructed 
in  the  built-up  parts  of  New  York,  has  been  made  so  clear  by  Mr.  Watson,  whose  ex- 
perience with  sprinklers  exceeds  that  of  any  other  engineer;  the  annoyance  from  the 
odors  and  flies  which  sprinkling  filters  produce  are  so  well  known  to  all  who  have  seen 
them  in  operation  in  warm  weather  and  the  areas  of  land  required  for  them  are  so 
large  that  the  Commission  and  Messrs.  Fowler,  Fuller  and  Datesman  have  not  felt 
warranted  in  including  this  form  of  treatment  among  the  possibilities  of  local  treat- 
ment. There  therefore  remain  only  screens  and  settling  basins  to  be  considered  among 
the  methods  which  may  be  used  for  the  local  and  partial  treatment  of  the  sewage. 

The  Commission,  which  has  given  much  study  to  the  possible  use  of  screens  and 
settling  basins  under  a  wide  variety  of  circumstances,  is  of  the  opinion  that  these  types 
of  apparatus  can  be  of  great  help  in  disposing  of  the  city's  sewage.  Each  type  of  appa- 
ratus has  its  functions  and  limitations.  Settling  basins  should  not,  in  the  Commis- 
sion's opinion,  be  constructed  in  the  built-up  portions  of  the  city.  The  plant  proposed 
by  the  Commission  for  Wards  Island,  the  four  plants  for  the  protection  of  the  Upper 
East  river  and  the  plant  on  the  ocean  island  would  consist  of  settling  basins.  The 
Commission  has  recommended  that  that  part  of  Manhattan's  sewage  which  flows 
toward  the  Hudson,  that  part  of  Brooklyn's  sewage  which  flows  toward  Upper  New 
York  bay  and  that  part  of  the  sewage  of  Manhattan  and  Brooklyn  which  is  tributary 
to  the  Lower  East  river  and  which  cannot  be  included  in  the  ocean  outlet  should  pass 
through  screens. 

In  the  Commission's  opinion  screens  would  be  capable  of  removing  most  solid 
matters  which  are  separately  recognizable  as  of  sewage  origin,  but  would  not  effect 
much  more  improvement.  The  demand  upon  the  dissolved  oxygen  would  not  be  mate- 
rially lessened.  If  settling  basins  were  employed,  about  fifty  per  cent,  of  the  solid 
matter  would  be  removed  and  the  demand  which  the  organic  matters  of  the  sewage 
would  make  upon  the  dissolved  oxygen  would  be  reduced  about  twenty  per  cent. 

No  barrier  would  be  provided  by  either  screens  or  settling  basins  against  the  bac- 
terial pollution  of  the  water.  With  settling  basins  the  sewage  would  be  retained  for 
a  period  of  approximately  two  hours  and  the  settlings  in  the  form  of  black,  semi-liquid 
sludge  would  be  put  on  board  vessels  and  transported  to  sea.  Neither  process  would 
lessen  the  unpleasantly  turbid  appearance  of  the  sewage  streams  at  the  points  of  dis- 
charge. This  could  only  be  prevented  by  discharging  the  sewage  at  the  bottom  of  deep 
and  rapidly  flowing  tidal  channels. 

As  a  general  procedure  it  would  not  be  feasible  to  construct  settling  basins  be- 
neath the  streets.  The  space  required  would  be  prohibitive.  If  built  upon  the  Em- 
scher  or  Dortmund  tank  principle,  either  of  which  is  more  economical  of  space  than 


INTRODUCTION  169 

any  other  known  form,  settling  basins  to  provide  two  hours'  settlement  for  200,000,000 
gallons  of  sewage  would  extend  over  one  mile. 

Settling  tanks  beneath  the  streets  would  be  difficult  to  build  and  operate  because 
of  the  confined  space  available,  inconvenient  shape  of  the  tanks  and  tidal  interference. 
Trouble  in  inspecting  and  cleaning  the  basins  might  be  expected  through  want  of 
proper  light  and  ventilation.  There  would  be  considerable  risk  of  nuisance  and  danger 
of  explosion  from  the  gases  produced  from  the  decomposition  of  the  sewage,  from  gas- 
olene fumes  and  from  illuminating  gas. 

If  the  tanks  were  built  elsewhere  than  under  the  streets,  property  would  have  to 
be  acquired  for  them.  The  area  of  land  required  for  settling  basins  to  deal  with  200,- 
000,000  gallons  per  day  would  be  about  six  acres. 

The  Commission  does  not  share  the  opinion  that  the  location  of  settling  basins  in 
the  built-up  parts  of  the  city  would  be  free  from  public  objection.  Granting  that  they 
would  not  produce  offensive  odors,  it  seems  certain  that  property  holders  in  the 
vicinity  would  make  vigorous  protest  against  the  construction  of  such  works,  in  the 
belief,  mistaken  though  it  might  be,  that  the  health  and  comfort  of  the  neighborhood 
were  seriously  threatened.  The  object  of  the  works  would  avowedly  be  to  extract  as 
much  as  possible  of  the  offensive  and  dangerous  materials  from  the  sewage,  and  before 
they  were  disposed  of  they  would  have  to  be  stored,  transported  to  the  water  front, 
loaded  upon  vessels  and  shipped  to  sea. 

As  to  cost,  Mr.  Fuller's  preliminary  estimates  indicated  to  him  that  settling  basins 
would  be  about  one-fourth  as  expensive  for  200,000,000  gallons  of  sewage  as  the  Com- 
mission's outlet  island  project,  including  the  purchase  of  the  land  which  the  settling 
basins  would  require.  The  costs  assumed  by  Mr.  Fuller  for  the  outlet  island  scheme 
are  based  upon  the  Commission's  earliest  calculations  for  that  project.  Later  studies 
have  shown  that  the  cost  would  be  materially  reduced  by  making  less  than  the  large 
allowance  originally  proposed  for  storm  water.  By  providing  for  the  collection  of  the 
dry-weather  flow,  the  cost  of  the  outlet  island  project  can  be  reduced  to  about 
$14,000,000  and  the  annual  charges  to  about  $1,000,000. 

A  careful  consideration  of  the  cost  of  disposing  of  the  same  quantity  of  sewage 
by  locally  placed  settling  basins  and  submerged  outfalls  indicates  an  initial  expense 
of  $9,191,000  and  an  annual  charge  of  $766,000.  Comparison  of  the  outlet  island  and 
local  settling  basin  projects  in  accordance  with  the  revised  estimates  indicates  that 
the  outlet  island  project  would  cost  about  one  and  one-half  times  more  to  build  and 
about  one  and  one-third  times  more  to  operate  than  would  local  and  partial  treatment 
by  means  of  settling  basins. 

When  the  cost  of  the  Commission's  outlet  island  project  is  compared  with  the 


170  REPORTS  OF  EXPERTS 

project  for  local  settling  basins  on  the  basis  of  organic  matter  removed,  a  heavy 
balance  is  seen  to  lie  in  favor  of  the  outlet  island  project.  In  this  connection,  it  must 
be  remembered  that  the  outlet  island  would  remove  from  the  Lower  East  river  100  per 
cent,  of  the  oxygen-demanding  constituents  of  the  sewage  and  that  settling  basins 
would  remove  not  over  20  to  25  per  cent.  On  the  basis  of  each  per  cent,  removed,  the 
locally  placed  tanks  would  cost  $22,589  and  the  outlet  island  $10,273.  These  calcula- 
tions are  based  upon  the  assumption  that  about  200  million  gallons  per  day  would  be 
dealt  with  in  each  case. 

The  ocean  island  could  provide  an  outlet  for  the  sewage  of  the  western  part  of  the 
Jamaica  Bay  Division  and  if  so  used  would  cost  about  $2,000,000  less  than  the  project 
for  local  settling  basins  in  the  Lower  East  river  territory  and  the  project  for  collect- 
ing the  sewage  of  the  western  Jamaica  bay  territory  to  Barren  Island. 

Another  serious  objection  to  the  plan  of  locally  placed  settling  tanks  for  the  pro- 
tection of  the  Lower  East  river  lies  in  the  fact  that  this  method  of  disposing  of  the 
sewage  would  not  lend  itself  to  a  more  efficient  treatment  of  the  sewage  in  case  sedi- 
mentation did  not  prove  adequate.  Unlike  the  sedimentation  works  recommended  by 
the  Commission  for  Wards  Island  and  some  other  isolated  points,  settling  tanks  could 
not  be  converted  into  chemical  precipitation  basins  in  the  compactly  built-up  sections 
of  the  city  without  involving  serious  chance  of  nuisance  in  the  immediate  neighbor- 
hood, much  inconvenience  in  the  handling  of  the  chemicals  and  high  cost  for  the  dis- 
posal of  the  large  volumes  of  sludge  which  would  be  produced.  If,  in  the  course  of 
time,  a  more  comprehensive  plan  had  to  be  adopted  to  protect  the  Lower  East  river, 
as  the  Commission  believes,  it  would  be  necessary  to  abandon  the  settling  basins  and 
carry  out  the  Commission's  plan  of  conveying  the  sewage  to  the  outlet  island.  This 
procedure  would  then  prove  to  be  much  more  costly  than  if  provided  for  in  the  first 
place. 

To  permit  sludge  to  form  on  the  river  bottom  of  the  Upper  and  Lower  East  rivers, 
and  subsequently  remove  it  by  suction  dredges  would  not,  in  the  Commission's  opinion, 
afford  material  help  in  solving  the  sewage  problem.  The  sludge-making  materials  of 
sewage  are  capable  of  producing  much  harm  both  before  they  are  deposited  and  during 
the  time  they  are  resting  upon  the  harbor  bottom,  and  the  removal  of  this  material  by 
suction  dredges  would  be  attended  by  many  practical  difficulties,  including  interference 
with  traffic,  nuisance,  expense,  inconvenience  and,  when  the  dredges  were  at  work,  in- 
tense pollution  of  the  overlying  waters. 

The  engineering  difficulties  which  have  been  pointed  out  in  connection  with  the 
ocean  island  project  have  been  foreseen  by  the  Commission  and  the  opinion  is  held  that 
they  can  be  overcome  without  serious  trouble.    The  mean  velocity  calculated  for  the 


INTRODUCTION 


171 


sewage  in  the  force  main  from  the  pumping  station  to  the  island  is  2y2  feet  per  second 
and  this  would  be  obtained  as  soon  as  the  works  were  built.  It  is  to  be  noted  that 
the  ocean  island  project  would  not  be  built  for  the  distant  future,  but  would  operate 
at  its  full  capacity  as  soon  as  constructed. 

The  Commission  has  given  careful  attention  to  the  possibility  of  carrying  sewage 
from  the  Lower  East  river  territory  to  an  island  to  be  built  at  the  south  of  Governors 
Island,  assuming,  for  the  purposes  of  study,  that  permission  could  be  obtained  from 
the  National  Government  for  such  construction.  The  cost  of  this  island,  including  the 
construction  of  the  works  tributary  to  it  and  the  tanks  and  appurtenances  for  treat- 
ing the  sewage,  approaches  the  cost  of  the  ocean  island  project,  but  the  opportunities 
available  for  the  disposal  of  the  effluent  would  not  be  so  satisfactory.  It  is  to  be  re- 
membered that  the  point  at  which  the  outfall  would  have  to  be  located  would  be  about 
2y2  miles  from  the  Passaic  Valley  sewer,  whose  effluent  may  be  expected  to  make  a  heavy 
and  increasing  demand  upon  the  oxygen  of  the  surrounding  waters.  Sprinkling  filters  at 
this  point  would  not  be  permissible,  in  the  Commission's  opinion,  because  of  the  odors 
which  they  would  produce,  popular  objection  and  cost. 

Such  weight  as  is  to  be  given  to  established  custom  in  engineering  work  is  strongly 
opposed  to  the  local  and  partial  treatment  of  sewage  as  distinguished  from  its  removal 
to  a  distant  point  for  final  disposition.  The  object  of  main  drainage  systems  is  to  carry 
sewage  away  to  some  suitable  point  or  points  where  as  much  of  the  offensive  material 
as  necessary  can  be  removed,  so  that  the  effluent  may  be  discharged  into  a  neighbor- 
ing lake,  river  or  arm  of  the  sea.  Thus  London  carries  its  sewage  beyond  the  limits 
of  Greater  London  in  order  to  find  a  suitable  locality  for  settling  basin  treatment. 
Paris  takes  its  sewage  to  Clichy  and  there  pumps  it  to  irrigation  fields.  Berlin  pumps 
its  sewage  out  of  the  city  to  farms  situated  in  various  directions.  Boston  and  the  cities 
and  towns  in  its  vicinity  send  their  sewage  to  sea  through  three  outlets  situated  as  far 
as  practicable  from  the  harbor  shores.   These  illustrations  could  be  multiplied. 

The  employment  of  grit  chambers  and  screens  for  the  treatment  of  a  large  part  of 
the  sewage  of  New  York  represents  to  some  extent  a  departure  from  established  prece- 
dent. Examples  are  much  more  easily  found  of  cities  which  screen  their  sewage  within 
their  limits  than  those  which  attempt  more  thorough  treatment.  Coarse  screening  and 
the  removal  of  grit  are  not  uncommonly  done  before  sewage  is  sent  to  a  distance  and 
comparatively  fine  screening  may  be  resorted  to  without  serious  probability  of  nuisance. 

Mr.  Fuller  places  reliance  upon  the  experience  of  some  other  cities  to  support 
his  position  with  regard  to  the  ability  of  natural  bodies  of  water  to  assimilate 
sewage,  but  he  recognizes  that  the  capacity  of  New  York  harbor  with  its  oscillating  salt 
water  is  not  the  same  as  the  capacity  of  inland  lakes,  much  less  that  of  rivers,  such  as 
receive  the  sewage  of  Chicago,  Columbus  and  Lawrence,  for  example.  London  is 
selected  by  him  as  affording  an  instructive  instance  of  a  city  whose  sewage  is  dis- 


172  REPORTS  OF  EXPERTS 

charged  into  tidal  water  with  but  little  preparatory  treatment  and  with  satisfactory 
results.  The  Metropolitan  Sewerage  Commission  has  taken  pains  to  investigate  the 
conditions  at  London  among  many  other  places  where  sewage  is  discharged  into  tidal 
water. 

The  following  letter  from  the  Secretary  of  the  London  Port  Authority,  dated 
December  10,  1913,  describes  a  condition  which,  although  tolerated  in  the  Thames  below 
London,  would  not  be  suitable  in  the  built-up  sections  of  New  York  City: 

10th  December,  1913. 

Deab  Sib: 

In  reply  to  your  letter  of  the  2d  inscant,  your  assumption  is  correct  that  notwithstanding  the  separation 
of  the  greater  part  of  the  solids  from  the  London  sewage  effluent,  there  is  enough  solid  matter  remaining  in 
suspension  to  represent  in  the  course  of  the  year  a  very  large  amount  of  mud-forming  material  which  adds  to 
the  dredging  obligations  of  the  Authority. 

In  a  report  which  I  made  on  the  subject  in  1908  I  found  that  the  total  volume  of  effluent  passed  into  the 
River  annually  was  ninety  thousand  millions  of  gallons  which  contained  12  to  13  grains  per  gallon  of  solid 
matter  dried  at  boiling  point.    This,  I  roughly  calculated,  would  represent  about  330,000  cubic  yards  of  mud. 

With  regard  to  unpleasant  odors,  they  are  most  pronounced  at  the  points  of  discharge,  viz.,  Barking  and 
Crossness,  a  distance  of  from  12  to  13  miles  below  London  Bridge.  On  the  flood  tide  an  appreciable  effect  is 
noticed  for  a  few  miles  above  the  London  Bridge,  and  on  the  ebb  tide  this  would  be  perceptible  until  the  wider 
and  Salter  waters  of  the  River  were  reached ;  say,  down  to  Northfleet  Hope,  a  distance  of  about  25  miles 
below  London  Bridge,  or  12  miles  below  the  point  of  discharge.  The  odors,  however,  would  not  extend  inland 
beyond  the  immediate  banks  of  the  River. 

I  regret  that  I  am  unable  to  tell  you  precisely  how  often  the  temperature  rises  above  65  degrees  or  higher, 
as  the  English  summers  greatly  vary  in  temperature.  With  the  average  amount  of  sunshine  I  should  say  that 
this  temperature  is  reached  toward  the  end  of  June  and,  after  a  week  of  dry,  sunny  weather,  would  always 
be  attained  up  to  and  including  the  first  week  in  September. 

Yours  faithfully, 

(Signed)       F.  AGLIFFE, 

The  President,  Secretary. 
Metropolitan  Sewerage  Commission  of  New  York, 
17  Battery  Place,  N.  Y.  City. 

The  experience  of  London,  Hamburg,  Washington  and  Philadelphia  are  cited  by 
Mr.  Hering  to  show  that  sewage  is  often  discharged  untreated,  or  nearly  so,  into  water 
courses  of  brackish  and  upland  water  without  nuisance.  It  may  be  remarked  that 
these  references  do  not  support  the  argument  for  a  partial  and  local  treatment  of  the 
sewage,  inasmuch  as  they  refer  to  situations  quite  unlike  that  of  New  York.  The  fore- 
going letter  from  the  Port  of  London  Authority  shows  that  the  Thames  for  a  dozen  miles 
above  and  below  the  outlets  produces  odors  which  would  be  inadmissible  in  New  York. 
Nor  should  Hamburg  be  taken  as  a  model,  since  the  discharge  of  that  city's  sewage  into 
the  turbid  Elbe  is  visible  from  the  shore.  Mr.  Hering  cites  Washington,  but  it  should 
be  explained  that  the  Washington  sewage  is  probably  one  of  the  most  dilute  in  the 
United  States  and  the  Potomac  river  is  an  alluvial  stream  whose  abundant  storm 
waters  soon  flush  away  such  sewage  impurities  as  gain  access  to  it.  Philadelphia  is 
referred  to,  but  it  is  significant  that  Philadelphia  is  completing  plans  for  a  system  of 
main  drainage  and  sewage  disposal  which  is  likely  to  be  far  more  radical  than  that  pro- 
posed by  the  Metropolitan  Sewerage  Commission  for  New  York. 


REPORT  OF  GILBERT  J.  FOWLER 


173 


SECTION  I 

REPORT  OF  GILBERT  J.  FOWLER,  D.  Sc. 

To  the  President  and  Members  op  the  Metropolitan  Sewerage  Commission  of 
New  York. 

Gentlemen  :  In  accordance  with  the  request  of  the  Metropolitan  Sewerage  Com- 
mission, conveyed  to  me  by  the  Pr?sident,  Dr.  George  A.  Soper,  in  a  letter  dated  Septem- 
ber 27,  1912,  I  arrived  in  New  York  on  the  10th  November,  1912,  and  remained,  with 
brief  absences  in  Boston,  till  Wednesday,  the  27th  November. 

During  this  time  the  following  inspections  were  made : 
By  water :  1.  Upper  bay, 

2.  East  river  to  Long  Island  sound, 

3.  Round  Manhattan  Island, 

4.  Through  the  Narrows  to  Far  Rockaway  and  into  Jamaica  bay. 

By  land:   5.  To  Gravesend  bay,  Coney  Island,  Sheepshead  bay  and  Canarsie,  visiting 
disposal  works  at  Sheepshead  bay,  Paerdegat  basin  and  26th  Ward; 
6.  To  Newtown  creek,  returning  to  Manhattan,  recrossing  the  Lower  East 
river  below  Hell  Gate  and  skirting  the  edge  of  the  Upper  East  river,  in- 
cluding Steinway,  Flushing  bay,  Whitestone  and  Douglaston. 
I  also  visited  Boston,  and  through  the  courtesy  of  the  Massachusetts  Board  of 
Health,  was  able  to  inspect  the  three  types  of  sea  outfall  there.   The  same  day  I  visited 
the  Lawrence  experimental  station  and  discussed  the  work  being  done  with  the  chief 
chemist.   On  these  various  expeditions  numerous  photos  were  taken  of  important  points 
such  as  some  of  the  larger  sewer  outlets,  proposed  places  of  discharge,  etc. 

A  good  deal  of  time  was  spent  in  the  laboratory  of  the  Commission,  overlooking 
and  discussing  experiments  on  the  possibilities  of  electrolyzed  sea  water  as  a  precipi- 
tating and  sterilizing  agent  for  the  sewage.  I  also  had  much  conversation  and  discus- 
sion with  reference  to  the  data  accumulated  by  the  Commission  and  was  shown 
numerous  data  hitherto  unpublished,  especially  in  reference  to  the  possibilities  of 
complete  nitrification  taking  place  in  mixtures  of  sea  water  and  fresh  water. 

The  President  was  good  enough  to  demonstrate  for  me  the  method  used  by  the 
Commission  in  their  fundamentally  important  work  on  the  dissolved  oxygen  in  New 
York  harbor.  The  method  is  rapid  and  accurate  and  well  suited  to  the  conditions  of 
investigation.  I  have  carefully  studied  both  before  and  since  my  visit  to  New  York  the 
extensive  and  valuable  reports  issued  by  the  Commission  as  well  as  the  report  by  Major 
Black  and  Prof.  Phelps. 

Immediate  Conclusions 

I  was  impressed  at  the  outset  by  the  vastness  and  complexity  of  the  problem  to  be 
dealt  with.  London  may  have  a  larger  present  population,  but  the  conditions  for  dis- 
charge are  infinitely  simpler. 

In  addition  to  the  rapidly  increasing  population  directly  or  indirectly  discharging 
its  sewage  into  the  harbor,  the  problem  is  complicated  by  the  outstanding  facts,  viz. : — 
(1)  the  growing  scarcity  and  value  of  unbuilt  upon  land  in  the  vicinity  of  the  harbor, 


174 


REPORTS  OP  EXPERTS 


(2)  the  comparatively  small  amount  of  water  available  for  flushing  out  the  bay,  this 
being  limited  practically  to  the  flow  of  the  Hudson.  The  thickly  populated  districts 
abutting  on  the  Harlem  river  and  the  Lower  East  river  discharge  into  waters  which 
ebb  and  flow  with  the  tide,  but  suffer  very  little  actual  change,  little  or  no  excess  water 
passing  out  of  the  bay  or  into  it  at  each  tide. 

As  a  consequence,  the  conditions  to  be  met  with  in  the  Harlem  and  Lower 
East  rivers  call  for  immediate  action.  Not  only  is  the  bottom  polluted,  but  the  water, 
even  in  favorably  situated  portions  of  these  rivers,  is  deficient  in  oxygen,  in  the  majority 
of  cases  to  nearly  50  per  cent.  In  many  places  there  are  local  nuisances  already,  and 
floating  faecal  matter,  paper,  etc.,  are  in  frequent  evidence.  What  the  conditions  are 
likely  to  be  when  the  surrounding  districts,  increasing  as  they  are  now  doing,  to  say 
the  population  of  1940,  it  is  not  pleasant  to  conjecture.  It  is  evident  that  something 
will  have  to  be  done  here  and  done  at  once.  When  the  volume  of  sewage  to  be  dealt 
with — over  350  million  gallons  per  day  at  the  present  time  and  more  than  700  million 
gallons  by  1940 — is  considered,  it  is  evident  that  for  this  section  of  the  work  alone  con- 
siderable expenditure  will  have  to  be  faced.* 

In  view  of  the  very  large  expenditure  involved,  it  is  difficult  to  exaggerate  the  im- 
portance of  adequate  preliminary  studies  and  the  work  of  the  Commission  throughout 
appears  to  me  to  be  a  model  of  the  way  in  which  such  investigations  should  be  carried 
out.  The  conditions  are  so  complicated,  owing  to  the  diversified  character  of  the  land 
and  water  areas  constituting  New  York  harbor  and  its  surroundings,  that  endeavors 
to  reproduce  them  artificially,  as  is  often  done  in  research  work,  are  likely  to  be  only 
partially  successful.  The  method  of  thoroughly  studying  the  actual  state  of  things 
obtaining  in  the  bay  and  other  waters  in  the  vicinity  under  all  conditions  of  season,  tide 
and  weather,  as  has  been  done  by  the  Commission,  seems  the  only  possible  one,  and  the 
work  has  been  done  with  masterly  completeness.  No  question  necessary  for  the  forma- 
tion of  a  right  judgment  on  the  questions  which  should  be  settled  at  this  time  appears 
to  have  been  left  unstudied  by  the  Commission. 

The  citizens  of  New  York  may  rest  assured  that  the  large  sum  of  money  they  will 
be  called  upon  to  pay  for  the  protection  of  their  harbor  will  not  be  asked  for  except  as 
the  result  of  opinions  formed  after  years  of  study  much  more  complete  than  is  gen- 
erally given  to  such  a  subject.  Every  year,  however,  the  conditions  now  existing  must 
necessarily  grow  worse  and,  while  in  the  case  of  a  growing  science  like  that  of  sewage 
disposal  it  is  well  to  hasten  slowly,  yet  through  the  labors  of  the  Commission  there  will 
exist  no  justification  on  the  score  of  imperfectly  known  data  for  postponing  certain  most 
necessary  works. 

Principles  Governing  Consideration  of  the  Problem 

The  conditions  which  must  be  realized  if  the  constituents  of  sewage  are  to  be 
rendered  inoffensive  or  finally  mineralized  are  essentially  the  same  whether  the  disposal 
be  by  irrigation  upon  land,  filtration  through  artificial  biological  filters,  or  dilution  with 
fresh  or  salt  water.  The  process  is  in  all  cases  one  of  oxidation,  i.  e.,  practically  speak- 
ing, combustion,  and  if  it  is  to  be  conducted  without  nuisance,  enough  oxygen  must  be 
present  at  all  stages  of  the  process  to  prevent  the  formation  of  evil-smelling  products. 

It  is  perfectly  legitimate  to  use  the  oxygen  dissolved  either  in  sea  or  river  water 

"Report  Metropolitan  Sewerage  Commission  of  New  York.  August,  1912,  p.  28. 


REPORT  OF  GILBERT  J.  FOWLER 


175 


in  order  to  oxidize  sewage.  Under  proper  conditions  of  discharge,  complete  trans- 
formation and  mineralization  of  the  sewage  matters  can  be  effected  in  this  way  with 
less  nuisance  than  often  accompanies  treatment  on  filters  or  on  land. 

The  question  of  the  margin  of  safety  which  should  be  allowed  if  nuisance  is  to  be 
avoided  has  been  the  subject  of  reports  by  a  number  of  well-known  experts  to  the 
Metropolitan  Sewage  Commission*  and  all  of  these  reports  agreed  that  under  no  cir- 
cumstances should  be  dissolved  oxygen  in  the  harbor  be  allowed  to  sink  to  below  50  per 
cent,  of  saturation.  In  this  opinion  I  concur.  It  will,  however,  be  most  unwise  to  be 
content  with  a  margin  simply  sufficient  to  barely  eliminate  nuisance. 

Two  main  considerations  govern  the  situation  from  the  point  of  view  of  public 
policy;  these  may  be  described  as  considerations  of  Health  and  Welfare. 

Health.  There  are  obvious  ways  in  which  public  health  may  be  directly  affected 
by  the  filthy  conditions  of  parts  of  the  harbor  or  even  by  the  apparently  innocuous  dis- 
charge of  sewage  effluent. 

It  is  not  a  pleasant  sight  to  see  numbers  of  floating  fseces  washing  in  and  about 
piers  where  food  supplies  are  landed  from  lighters,  some  of  which  have  a  low  free  board. 
Gulls  and  flies  may  also  quite  possibly  be  carriers  of  infectious  material  under  such 
conditions. 

The  question  of  oysters  is  of  more  direct  importance.  Even  if  sewage  or  sewage 
effluent  is  actually  sterilized,  the  growth  of  oysters  near  an  outfall  is  always  a  possible 
source  of  danger,  and  while  it  is  quite  easy  to  exaggerate  this,  yet  it  can  never  be  in 
accordance  with  right  sanitation  for  an  article  of  food  to  be  thus  contaminated. 

The  pollution  of  bathing  sites  has  been  dealt  with  at  length  by  the  Commission. f 
The  conditions  which  at  present  exist  are  unsatisfactory  in  the  extreme. 

The  carrying  of  polluted  driftwood  daily  into  the  homes  of  the  poor  in  the  neigh- 
borhood of  the  water  front  does  not  tend  to  raise  the  standard  of  cleanliness  in  such 
homes  and  should  be  prevented  rather  by  stopping  pollution  than  by  forbidding  what 
is  in  itself  a  reasonable  and  thrifty  proceeding. 

But  even  more  important  than  the  direct  and  obvious  ways  in  which  the  public 
health  is  affected  by  the  polluted  condition  of  the  harbor  waters  is  the  practically  un- 
conscious lowering  of  that  sense  of  decency  and  cleanliness  of  living  which  must  be 
maintained  if  the  efforts  of  social  reformers  are  to  have  any  serious  result. 

Crowds  of  people  from  the  poorer  quarters  of  New  York  throng  the  recreation 
piers  and  pleasure  drives  on  the  water  front.  If  it  is  obvious  to  them  that  those  in 
authority,  who  have  the  power,  are  yet  unconcerned  to  abate  uncleanly  surroundings, 
the  already  not  inconsiderable  effort  required  to  maintain  a  decent  spot  of  home  life 
in  a  mean  environment  will  be  rendered  even  harder  to  achieve. 

Welfare.  The  second  consideration,  viz.,  that  of  icelfare,  as  it  has  been  termed,  is 
perhaps  less  obvious,  but  is  most  important  when  expensive  works,  the  use  of  which  is 
partly  for  future  generations,  have  to  be  considered. 

A  study  of  the  history  of  sanitation,  such,  for  example,  as  was  possible  in  the  his- 
torical section  at  the  International  Hygiene  Exhibition  in  Dresden  in  1911,  will  show 
that,  up  to  comparatively  recent  times,  conditions  were  tolerated  which  to  us  would 
seem  unspeakable.  Yet  even  now  the  standard  of  requirement  is  constantly  rising. 
One  may,  indeed,  frankly  say  that  the  modern  American  bathroom,  both  in  its  fittings 
and  the  frequency  with  which  it  is  to  be  found,  is  a  distinct  advance  upon  what  is 

•Report  Metropolitan  Sewerage  Commission  of  New  York,  August,  1912,  pp.  69-164. 
tReport  Metropolitan  Sewerage  Commission  of  New  York,  April  30,  1910,  pp.  486-497. 


176 


REPORTS  OP  EXPERTS 


common  even  in  England.  Such  a  bathroom,  however,  increases  the  difficulty  of  the 
sewage  problem,  and  in  looking  forward  to  the  future,  similar  advances  in  public  re- 
quirements must  always  be  reckoned  with.  The  idealism  manifested  in  such  great 
buildings  as  the  Pennsylvania  Railroad  station  and  the  Metropolitan  Museum  of  Art 
and  the  parks  and  playgrounds  of  the  city  will  find  its  further  development  in  a  demand 
for  brightness  and  beauty  in  the  surrounding  water  spaces.  Nor  is  such  idealism  unre- 
lated to  more  purely  economic  prosperity.  The  true  solution  of  any  problem  is  true  at 
all  points,  sanitary,  aesthetic,  ethical  and  economic. 

Apart  from  the  question  of  affecting  the  vitality,  and  consequently  wage  earning 
capacity  of  the  people,  the  reputation  of  a  port  is  a  very  essential  factor  in  its  commer- 
cial prosperity.  The  condition  of  the  Clyde  and  of  the  Manchester  ship  canal  was  for 
many  years  a  by-word.  The  great  sewerage  and  sewage  disposal  works  at  Glasgow, 
carried  out  at  a  total  cost  of  over  £2,000,000  for  800,000  people,  have  been  the  means 
of  rehabilitating  the  reputation  of  the  Clyde  and  adding  to  the  amenities  of  life,  plea- 
sure trips  being  now  possible  from  the  Broomielaw  to  the  Firth  of  Clyde. 

The  large  amount  of  money  spent  on  sewage  works  in  the  watershed  of  the  Mersey 
and  Irwell  is,  apart  from  the  increasing  expenditure  of  Manchester  itself,  slowly  but 
steadily  improving  the  water  of  the  Manchester  ship  canal. 

At  one  time  the  stench  from  the  polluted  Thames  in  hot  weather  rendered  the  com- 
mittee rooms  in  the  houses  of  parliament  in  London  uninhabitable.  By  the  removal 
of  the  sewage  to  treatment  works  and  outfalls  lower  down  the  river  this  nuisance  has 
been  abolished,  and  London  is  now  one  of  the  healthiest  and  best  drained  cities  in  the 
world. 

In  the  case  of  the  three  cities  above  referred  to,  their  works  were  carried  out  under 
urgent  pressure  of  obvious  and  almost  intolerable  nuisances  from  the  polluted  streams. 
New  York  should  deal  with  her  problem  before  such  acute  conditions  arise. 

The  foregoing  general  view  of  the  situation  clearly  indicates  that  any  scheme 
which  is  decided  upon  must  not  block  the  commercial  avenues  of  the  future.  It  must 
be  so  designed  as  to  be  capable  of  expansion  as  the  needs  of  the  city  increase. 

Possible  Methods  of  Dealing  with  Sewage.  The  Ararious  possible  methods  which 
are  available  for  dealing  with  sewage  on  the  large  scale  may  be  broadly  divided  into  : 

1.  Direct  discharge  into  water, 

2.  Discharge  after  screening, 

3.  Discharge  after  sedimentation, 

4.  Discharge  after  chemical  treatment, 

5.  Discharge  after  filtration  in  some  form, 

6.  Discharge  after  combination  of  processes. 

The  proportional  amount  of  impurities  removed  by  these  processes  depends  on 
numerous  factors,  e.  g.,  the  freshness  and  strength  of  the  sewage.  Thus,  screening  will 
remove  a  much  greater  proportional  amount  from  very  fresh  sewage  than  from  sewage 
which  has  been  mixed  and  churned  up  for  many  miles  in  a  trunk  sewer.  Chemical  treat- 
ment is  more  economical  with  strong  sewage  than  with  weak,  and  therefore  is  of  less 
advantage  with  American  sewage  than  with  European. 

Very  roughly,  it  may  perhaps  be  assumed  that  under  the  conditions  existing  in 
New  York,  of  the  nuisance-producing  solid  material  in  sewage  capable  of  producing 
deposits  of  sludge,  the  following  percentages  can  be  removed  by  the  respective 
processes : 


REPORT  OF  GILBERT  J.  FOWLER 


177 


Screening  and  grit  chambers 

Short  sedimentation  

Chemical  treatment  


3-6  per  cent. 
50  " 
75 


None  of  these  processes  seriously  affects  matters  in  solution.  Filtration  affects 
not  only  the  finely  divided  colloidal  matter  still  present  after  the  foregoing  processes, 
but  also  oxidizes  substances  in  solution. 

Which  of  these  methods  can  be  used  at  any  of  the  various  proposed  points  of  out- 
fall in  New  York  harbor  is  to  be  determined  by  local  conditions.  What  these  condi- 
tions are  is  considered  in  the  next  section. 


Broadly,  the  waters  of  that  part  of  New  York  harbor  which  lies  in  New  York 
State  may  be  considered  separately  as  follows: 
The  Hudson  river, 
The  Upper  bay, 

The  East  river  and  the  Harlem  river, 
Jamaica  bay. 

Of  these  the  Hudson  river  contains  the  most  dissolved  oxygen,  this  amounting  to 
over  90  per  cent,  of  saturation  in  the  centre  of  the  river  in  the  northern  part  of  Man- 
hattan and  diminishing  to  60  per  cent,  near  the  Battery.  The  Hudson  river  supplies 
practically  the  only  water  available  for  flushing  the  harbor.  All  along  the  edge  of  the 
Hudson  among  the  piers  objectionable  conditions  exist. 

The  Upper  Bay.  All  the  pollutions  from  the  waters  entering  the  harbor  at  certain 
states  of  the  tide,  as  well  as  those  resulting  from  direct  sewer  discharges  are  mixed  by 
tidal  currents  in  the  Upper  bay  and  a  proportion  of  the  solid  matters  is  doubtless  de- 
posited there  during  the  ebb  and  flow  of  the  tide.  This  is  evidenced  by  the  polluted 
character  of  the  dredgings  from  the  bottom  of  the  Upper  bay  at  nearty  every  point  of 
observation.  Considerable  deposit  of  sludge  has  been  found  south  of  Governor's  Island. 

The  general  appearance  of  the  waters  of  the  Upper  bay  is  by  no  means  attractive. 
Large  fields  of  sleek,  or  oily  film,  are  frequent  and,  more  objectionable,  are  masses  of 
floating  debris  in  which  large  quantities  of  frecal  matter  are  often  entangled.  The 
Gowanus  canal  is  little  better  than  an  open  sewer,  there  being  an  insufficient  circula- 
tion of  water  to  dilute  the  large  volumes  of  sewage  discharged  into  it. 

The  East  River  and  the  Harlem  River.  It  is  on  these  rivers,  especially  in  the 
Lower  East  river  and  the  Harlem,  that,  as  already  stated,  conditions  exist  which  call  for 
urgent  remedy. 

Large  sewers  discharge  from  the  thickly  populated  districts  on  both  sides  of  these 
waterways  and  there  is  little  or  no  net  tidal  discharge.  As  a  result,  the  bottom  of  the 
upper  East  river  as  far  as  Throg's  Neck  at  the  entrance  to  Long  Island  Sound  is  foul, 
and  in  the  Lower  East  river,  in  places  unaffected  by  the  ebb  and  flow  of  the  tidal  cur- 
rents, foul  deposits  occur. 

In  the  Lower  East  river  from  the  Williamsburg  Bridge  to  Hell  Gate  the  dissolved 
oxygen  present,  especially  in  the  summer  months,  is  not  much  more  than  50  per  cent,  of 
saturation.*  In  some  parts  of  the  Harlem  river  it  is  less  than  this.  There  are  por- 
tions of  the  Harlem  river  already  approaching  the  condition  of  the  Manchester  ship 
canal,  while  Newtown  creek  has  practically  reached  that  condition.   In  the  vicinity  of 

*In  the  summer  of  1912  some  samples  of  water  from  the  Lower  East  river,  near  the  Brooklyn  Bridge, 
were  found  to  contain  43  per  cent,  of  oxygen. 


The  Present  Polluted  Condition  of  the  Harbor 


178 


REPORTS  OF  EXPERTS 


Wallabout  basin  there  is  a  large  sewer  outlet  which  produces  a  small  lake  of  sewage 
in  its  vicinity,  which  is  most  objectionable. 

There  is  no  doubt  that  if  the  sewage  which  now  enters  crude  into  the  Lower  East 
river  and  the  Harlem  river  could  be  taken  up  and  dealt  with  in  a  satisfactory  manner 
very  great  benefit  would  accrue  not  only  to  these  waterways,  but  also  to  the  Upper  bay 
and  Upper  East  river,  into  which  much  of  the  sewage  eventually  finds  its  way. 

Jamaica  Bay.  The  characteristic  feature  of  Jamaica  bay  and  its  vicinity  is  the 
growing  summer  population  of  numerous  pleasure  resorts,  such  as  Bergen  Beach, 
Arverne,  Edgemere,  Canarsie  and  Rockaway.  The  conditions  which  I  saw  in  Novem- 
ber were,  therefore,  hardly  typical.  Effluents  from  treatment  works  at  Sheepshead  bay 
and  the  26th  Ward,  though  obviously  imperfectly  purified,  were  not  the  cause  of  serious 
visible  pollution. 

In  view  of  the  increasing  population  and  of  the  schemes  of  harbor  development 
which  are  being  considered,  it  will  be  necessary  before  very  long  comprehensively  to 
deal  with  the  sewage  which  at  present  discharges  into  the  bay. 

The  question  of  oyster  pollution  must  here  also  be  dealt  with,  and  it  should  be 
clearly  understood  that  ordinary  methods  of  treating  sewage  give  little  protection  from 
a  bacteriological  point  of  view,  while  processes  of  sterilization  may  easily  produce  a 
false  sense  of  security.  It  would  seem  best  for  oysters  not  to  be  taken  near  densely 
populated  centres,  as  under  such  circumstances  the  chance  of  pollution,  apart  from  the 
sewage  which  is  discharged  from  actual  sewage  outfalls,  are  considerable. 

Proposed  Remedies 

Seivage  Tributary  to  the  Lower  East  River  and  Harlem  River.  As  already  empha- 
sized, the  first  point  of  attack  in  dealing  with  the  problem  of  purification  of  New  York 
harbor  is  the  Lower  East  river  and  the  Harlem  river,  and  I  have  given  my  most  careful 
consideration  to  this  part  of  the  Commission's  work. 

After  much  study  the  Commission  have  concluded,  and  I  think  rightly,  that  the 
only  point  where  large  quantities  of  sewage  can  be  treated  in  this  neighborhood  is  at 
Wards  Island.  It  is  possible  to  pick  up  the  sewage  which  at  present  discharges  into 
the  Harlem  river  and  also  that  which  is  turned  out  of  the  large  sewer  at  Hunt's  Point 
and  bring  it  all  to  Ward's  Island,  where  it  can  be  treated  in  settling  tanks  and  the 
heavier  sludge  removed. 

.  Some  124  million  gallons  daily  would  be  thus  dealt  with  at  once,  and  over  400  mil- 
lion by  1940,*  and  would  be  discharged  into  the  swift  tidal  currents  at  Hell  Gate, 
where  the  best  possible  conditions  exist  for  mixing. 

Sedimentation,  however,  leaves  a  large  proportion  of  potential  solids  still  present, 
as  well  as  all  the  impurities  in  solution.  Treatment  by  chemicals  instead  of  by  plain 
sedimentation  would  remove  a  further  proportion  of  the  suspended  impurities,  but  the 
treatment  in  this  way  of  such  large  volumes  of  sewage  as  may  be  taken  there  involves 
numerous  difficulties  and  greatly  increased  cost,  which  would  weigh  heavily  against 
the  advantages  obtained.  Further  purification,  by  filtration,  at  Wards  Islaud  is  im- 
practicable, and  also  not  to  be  recommended  so  near  large  centres  of  population,  owing 
to  the  possibilities  of  aerial  nuisance  and  fly  trouble  on  large  areas  of  filters. 

It  becomes  matter,  therefore,  for  careful  consideration  how  far  the  concentration 
of  the  sewage  to  one  point  and  discharge  into  the  local  waters  after  elimination  of  the 

"Preliminary  Report  IV,  of  the  Metropolitan  Sewerage  Commission  on  the  Disposal  of  New  York's  Sewage, 
July,  1912. 


REPORT  OF  GILBERT  J.  FOWLER 


179 


grosser  solids  would  really  relieve  the  situation.  It  is  to  this  point  that  most  careful 
thought  has  heen  given  and  the  bearing  of  all  the  available  data  studied  under  every 
aspect. 

Owing  to  the  fact  that  the  waters  rushing  through  Hell  Gate  only  pass  back  and 
forth  with  the  tide  and  do  not  really  get  away  to  the  ocean,  it  is  evident  that  whatever 
sewage  is  discharged  at  Hell  Gate  is  largely  dependent  for  its  oxidation  on  the  oxygen 
in  the  water  with  which  it  mixes  in  one  tide.  The  Lower  East  river  is,  however,  highly 
polluted  and  the  discharged  effluent  will  therefore  not  get  much  help  from  it.  The  sit- 
uation, in  fact,  is  only  improved  by  the  elimination  of  the  grosser  solids  from  the 
sewage  of  the  Harlem  district.  If  the  situation  is  to  be  radically  improved  the  conclu- 
sion seems  inevitable  that  some  sewage  must  be  removed  from  the  Lower  East  river. 

From  figures  supplied  me  by  the  Commission,  I  calculate  that  if  the  sewage  of  the 
Harlem  territory  is  collected  and  passed  through  settlement  tanks  on  Wards  Island, 
and  if  the  sewage  of  those  parts  of  Brooklyn  and  Queens  which  would  ordinarily  dis- 
charge into  the  Lower  East  river  be  removed  altogether,  there  will  then  be  a  dilution 
representing  1  of  raw  sewage  to  200  of  water  in  the  Lower  East  river  at  mean  low  tide. 

This  is  a  considerable  improvement  on  present  conditions,  representing  a  removal 
from  the  Harlem  and  Upper  and  Lower  East  rivers  together,  of  about  50  per  cent,  of 
the  total  sewage  which  at  present  pollutes  them. 

It  is,  however,  from  the  Manhattan  waterfront  that  the  greatest  proportional  vol- 
ume of  sewage  enters  the  Lower  East  river.  It  exceeds  the  volume  discharged  into  this 
division  of  the  harbor  from  Brooklyn  and  Queens  by  about  50  per  cent.  The  further 
conclusion,  therefore,  is  forced  upon  one  that  a  really  satisfactory  solution  of  the  prob- 
lem must  involve  the  removal  of  this  sewage  also.  Indeed,  a  study  of  the  statistics 
show  that  if  this  is  not  done  the  Lower  East  river  in  1940  will  revert  to  a  condition 
even  worse  than  exists  to-day. 

Disposal  at  Sea  of  that  Part  of  the  Sewage  of  Brooklyn,  Queens  and  Manhattan 
Which  Would  Ordinarily  Discharge  into  the  Lower  East  River.  The  conditions  dis- 
cussed in  the  foregoing  section  show  clearly  that  the  sewage  from  these  districts  will 
have  to  be  removed  from  the  Lower  East  river  if  the  situation  is  to  be  properly  dealt 
with. 

From  the  researches  of  the  Commission  there  would  appear  to  be  three  possible 
outlets  for  this  sewage. 

The  first  possibility  is  to  take  it  to  Barren  Island  and  there  treat  it  in  tanks,  fol- 
lowed, possibly,  by  some  form  of  filtration  and  discharge  it  near  the  entrance  to 
Jamaica  bay.  At  the  same  point  would  be  collected  the  sewage  now  very  imperfectly 
dealt  with  at  the  various  sewage  works  discharging  into  the  creeks  on  the  northern 
shore  of  Jamaica  bay.    The  point  of  outlet  would  be  at  the  entrance  to  Jamaica  bay. 

Barren  Island  itself  is,  however,  little  more  than  half  a  mile  from  the  large  sum- 
mer population  on  the  Rockaway  peninsula,  and  if,  as  is  not  at  all  improbable  in  hot 
summer  weather,  some  amount  of  smell  should  arise  from  the  filters,  it  is  not  far 
enough  away  to  prevent  a  nuisance  to  these  people.  Moreover,  the  point  at  which  the 
effluent  would  discharge  is  not  half  a  mile  from  thronged  bathing  beaches.  There  are, 
therefore,  these  grave  objections  to  an  outlet  near  Barren  Island. 

A  second  alternative  proposition  has  been  considered,  viz.,  the  removal  of  the  sew- 
age to  the  west  side  of  Staten  Island,  with  the  erection  of  purification  works  there. 
Apart  from  engineering  difficulties  which  I  am  informed  exist  in  carrying  so  much 
sewage  across  the  very  deep  channel  of  the  Narrows,  the  conditions  of  final  discharge 


180 


REPORTS  OF  EXPERTS 


would  render  purification  by  biological  filters  necessary,  and  similar  objections  would 
again  arise  in  regard  to  nuisance  from  these  as  have  been  pointed  out  in  regard  to  the 
Barren  Island  project. 

Under  these  circumstances  a  third  alternative  has  been  suggested  which  seems 
to  me  to  have  much  to  recommend  it.  This  proposition  is  to  build  an  artificial  island 
well  out  in  the  Atlantic,  nearly  three  miles  from  the  shore  of  Coney  Island,  and  there 
construct  settling  tanks,  and  discharge  the  effluent  after  settlement  of  the  bulk  of  the 
suspended  solids,  into  deep  water,  with  proper  engineering  precautions  to  ensure  thor- 
ough mixing  of  the  effluent  with  the  sea  water. 

After  inspection  of  the  Boston  sea  outfalls  I  am  clearly  of  the  opinion  that  no  point 
of  outlet  should  be  less  than  40  feet  in  depth,  and  that  the  discharge  should  be  contin- 
uous so  as  to  minimize  the  quantity  sent  out  in  any  interval  of  time. 

The  sludge  deposited  in  the  tanks  could  be  readily  taken  well  out  to  sea  in  tank 
steamers  of  the  pattern  used  in  Europe,  as  at  Glasgow,  Manchester,  Salford  and 
London. 

I  understand  that  the  island  can  be  made  without  difficulty  from  the  spoil  and 
debris  from  excavations  in  New  York  City  at  present  taken  out  to  sea,  or  from  sand 
pumped  from  the  bottom  of  the  sea.  I  understand  also  that  it  will  be  possible  to  in- 
crease the  number  and  length  of  the  outfall  pipes  as  more  and  more  sewage  is  coupled 
up  to  the  island,  so  that  the  effluent  will  always  be  well  distributed  in  the  sea  water. 
The  operations  can  be  carried  on  without  causing  nuisance  to  anyone  and  the  conditions 
for  sea  disposal  of  sludge  in  tank  steamers  are  very  simple.  The  scheme  is  capable  of 
indefinite  expansion  as  more  sewage  is  taken  up,  as  the  size  of  the  island  itself  can  be 
increased  as  extensions  to  the  works  are  required. 

Many  matters  rather  of  detail  remain  for  further  consideration  in  regard  to  the 
methods  of  treatment  employed  both  at  what  may  be  termed  "Atlantic"  Island  and 
Wards  Island.  The  design  of  the  settlement  tanks  to  be  employed  is  a  question  of  im- 
portance. A  form  of  tank  is  to  be  preferred  which  would  expose  as  little  water  surface 
as  possible  and  also  allow  automatic  removal  of  the  sludge  by  the  pressure  of  the  super- 
natant water.  A  modified  form  of  two-story  tank  would  seem  well  suited  to  this  purpose. 

The  sludge  produced  by  the  thorough  fermentation  which  takes  place  in  the  so- 
called  Emscher  tanks,  while  greatly  reduced  in  bulk  and  offensiveness,  would  offer 
some  difficulties  in  carrying  to  sea,  owing  to  its  being  saturated  with  gas.  It  is  pos- 
sible that  judicious  admixture  with  salt  water  would  obviate  this  difficulty.  In  any 
event  the  disposal  of  sludge  is  the  least  difficult  part  of  the  problem.  There  will  not  be 
more,  for  a  long  time  at  any  rate,  than  is  at  present  handled  at  the  London  outfalls, 
and  the  conditions  of  sea  disposal  are  simpler  in  the  case  of  New  York. 

For  reasons  indicated  when  referring  to  works  on  Wards  Island,  I  do  not  recom- 
mend treatment  by  chemical  precipitants.  I  think,  however,  that  very  careful  study 
deserves  to  be  given  to  the  practicability  of  adding  a  small  dose  of  chlorine  to  the  efflu- 
ent, e.  g.,  by  the  addition  of  a  certain  volume  of  electrolyzed  sea  water.  This  would 
serve  the  double  purpose  of  deodorizing  what  may  be  a  somewhat  malodorous  effluent 
after  its  long  travel  through  the  sewers,  and  a  further  important  advantage  would  lie 
iD  preventing  an  immediate  call  upon  the  dissolved  oxygen  in  the  sea  at  the  point  of 
discharge,  and  thus  giving  time  for  more  thorough  mixing  and  aeration  to  take  place. 

Borne  Farther  Problems.  There  are  many  matters  of  importance  subsidiary  to  the 
large  scheme  outlined  above  which  call  for  brief  mention. 

A  system  of  screens  and  catchpits  has  been  designed  for  Manhattan  Island,  which 


REPORT  OF  GILBERT  J.  FOWLER 


181 


could  afterwards  be  used  for  screening  storm  Avater,  overflowing  from  the  main  sewers 
later  to  be  built.  It  is  in  my  view  important  that  this  should  be  carried  out,  in  order 
that  even  after  large  sums  have  been  spent  on  main  sewers  and  outfall  works  there 
should  not  be  public  disappointment  when  visible  pollution  is  seen  to  be  present  after 
every  shower  of  rain.  Before  such  refuse  is  removed,  however,  means  must  be  at  hand 
for  its  rapid  incineration  in  suitably  placed  destructors. 

The  scheme  of  outfalls  and  outfall  works  designed  by  the  Commission  for  the  dis- 
tricts abutting  on  the  Upper  East  river  seems  to  me  to  be  adequate,  at  any  rate,  for 
many  years.  The  outlets  are  all  in  deep  water  and  the  conditions  resemble  those  of 
the  Clyde  summer  resorts  or  English  lakes,  where  the  sewage  of  a  fairly  large  popula- 
tion is  disposed  of  without  serious  difficulty. 

Time  did  not  permit  me  to  study  the  problems  connected  with  Staten  Island 
actually  on  the  spot.  From  a  perusal  of  the  Commission's  report  on  the  disposal  of  the 
sewage  of  the  Richmond  Division  there  would  not  appear  to  be  any  special  difficulty  in 
dealing  with  the  situation  as  far  as  regards  the  responsibility  of  New  York  City. 

In  the  Arthur  Kill  and  Kill  van  Kull  we  are  approaching  the  problems  of  New 
Jersey.  I  have  not  been  called  upon  to  express  an  opinion  on  matters  which  are  a  sub- 
ject of  litigation.  One  may,  however,  safely  say  that  a  resolute  handling  by  New  York 
City  of  her  own  problems  is  likely  to  facilitate  an  equitable  conclusion. 

Summary  and  Conclusions 

After  careful  consideration  of  the  situation  as  it  has  been  placed  before  me,  I  am  of 
opinion  that  the  sewage  of  the  Harlem  district  should  be  collected  and  treated  in  sedi- 
mentation tanks  on  Ward's  Island. 

This  will  relieve  the  immediate  and  pressing  situation  on  the  Harlem  river.  It 
will,  however,  do  little  or  nothing  to  improve  the  Lower  East  river. 

It  is  of  equal  importance,  therefore,  that  the  scheme  be  pressed  forward  of  driving 
a  main  sewer  southwards  through  Brooklyn  to  an  artificial  island  well  out  from  shore 
in  the  Atlantic  ocean,  where  tanks  could  be  built  for  settling  out  the  heavier  suspended 
matters  and  removing  them  to  sea. 

Into  this  main  sewer  would  first  be  discharged  that  part  of  the  sewage  of  Brooklyn 
and  Manhattan  which  at  present  passes  in  a  crude  state  into  the  Lower  East  river. 
Later  more  of  the  sewage  of  Manhattan  should  be  coupled  up  to  this  sewer,  the  outlets 
at  the  artificial  island  being  extended  with  each  large  increment  of  sewage. 

Next,  the  sewage  from  the  Jamaica  Bay  Division  might  be  brought  to  the  island, 
and  finally,  if  thought  desirable,  the  sewage  which  during  all  this  time  had  received 
treatment  at  Wards  Island. 

By  this  sequence  of  procedure  the  experience  gained  at  Wards  Island  would  be  of 
value  in  designing  the  final  disposal  at  the  "Atlantic  Island,"  and  at  any  rate  a  large 
proportion  of  the  money  expended  in  tanks,  etc.,  at  Wards  Island  will  have  been  re- 
deemed before  the  works  are  abandoned.  The  expenditure  in  sewers  in  the  Harlem 
district  will  be  for  permanent  works  alone. 

The  order  of  carrying  out  the  various  needful  works  and  the  time  over  which  the 
construction  should  extend  would  all  be  matters  within  the  control  of  the  permanent 
commission  suggested  by  my  colleague,  Mr.  Watson,  with  whose  views  on  this  aspect 
of  the  question  I  heartily  concur. 

This  same  central  board  or  commission  would  care  for  the  other  less  immediately 


182 


REPORTS  OF  EXPERTS 


pressing,  but  still  highly  important,  problems  referred  to  in  the  later  paragraphs  of  the 
foregoing  report. 

The  above  represents  in  broad  outline  the  lines  upon  which,  in  my  opinion,  the  City 
of  New  York  should  proceed  in  its  endeavor  to  obtain  a  harbor  worthy  of  itself. 

It  must  again  be  emphasized  that  no  time  should  be  lost  in  setting  about  the  actual 
carrying  out  of  the  scheme.  It  must  of  necessity  take  a  number  of  years  to  complete, 
and  equally  of  necessity  the  condition  of  the  harbor  waters  must  become  progressively 
worse  if  nothing  is  done,  and  will  indeed  probably  be  worse  before  the  first  instalment 
of  the  work  is  completed. 

I  am,  however,  confident  that  the  citizens  of  New  York  will  show  the  same  deter- 
mination and  largeness  of  outlook  already  manifested  in  their  great  water  supply 
projects,  their  colossal  railway  undertakings  and  magnificent  bridges  and  public  insti- 
tutions, in  this  further  effort  after  social  well-being,  and  will  build  the  works  necessary 
to  cleanse  the  harbor  and  make  it  worthy  in  every  respect  of  its  great  position  as  the 
Gateway  of  the  West. 

Respectfully  submitted, 
Manchester,  February  10,  1913.  Gilbert  J.  Fowler. 

SECTION  II 

REPORT  OF  JOHN  D.  WATSON,  C.  E. 

To  the  President  and  Members  op  the  Metropolitan  Sewerage  Commission  of 
New  York. 

Gentlemen:  I  have  given  the  problem  of  the  sewerage  and  the  sewage  disposal 
of  your  great  city  my  close  and  careful  consideration  during  the  past  two  months. 

The  fortnight  which  I  spent  in  the  city  in  the  end  of  November  and  beginning  of 
December  gave  point  and  animation  to  the  study  which  was  not  otherwise  possible, 
and  I  take  this  opportunity  of  thanking  you  for  the  ready  access  you  gave  me  to  all 
your  documents,  plans  and  analytical  figures,  and  for  the  facilities  with  which  you  pro- 
vided me  in  the  inspection  of  every  part  of  the  area  which  I  thought  it  essential  to 
visit.  Allow  me  also  to  record  my  appreciation  of  the  exhaustive  preliminary  investi- 
gations which  you  have  made.  These  far  exceed  anything  which  I  have  hitherto  had 
experience  of,  and  the  fact  of  your  having  printed  them  renders  unnecessary  reference 
to  details  which  otherwise  would  have  had  to  be  given  in  this  report. 

The  Polluted  Condition  op  the  Harbor 

If  there  were  any  prospect  of  limits  being  set  to  the  bounds  of  New  York,  if  there 
were  any  signs  that  sufficient  accommodation  had  already  been  made  for  the  shipping  of 
the  port,  or  if  the  waters  of  the  harbor  were  so  foul  that  the  citizens  had  ceased  to 
regard  them  as  valuable  for  oher  than  utilitarian  purposes,  the  disposal  of  the  sewage — 
vast  as  the  volume  of  that  is — would  be  comparatively  easy.  But  it  is  quite  otherwise. 
The  city  is  more  than  the  capital  of  a  country;  it  is  the  greatest  city  of  a  continent. 
The  harbor  is  the  gateway  to  the  United  States,  and  the  noble  rivers  which  find  a  ready 
outlet  into  it  form,  with  the  harbor  proper,  a  port  which  affords  at  all  stages  of  the  tide 
no  halting  welcome  to  vessels  of  the  greatest  burden. 

When  I  first  had  the  pleasure  of  seeing  the  Hudson  between  Albany  and  New  York 
I  was  greatly  impressed  by  its  grandeur  and  its  purity;  when  I  motored  along  its  left 
bank  from  Riverside  Park  toward  the  city  boundary  at  Yonkers  in  brilliant  sunshine  I 
thought  it  the  Queen  of  Rivers,  and  I  cannot  believe  that  the  average  citizen  would 


REPORT  OF  JOHN  D.  WATSON 


183 


willingly  allow  it  to  become  visibly  polluted  with  sewage,  yet  the  facts  to  which  I 
shall  refer  will  prove  that  it  is  necessary  to  take  steps  now  to  guard  against  such  a 
contingency  in  the  immediate  future. 

Visible  Pollution.  The  numerous  analyses  of  the  harbor  waters  made  by  your  own 
officers,  supported  by  men  of  such  eminence  as  Professor  Phelps,  Dr.  Adeney  and  Dr. 
Fowler,  and  the  clear  evidence  of  pollution  which  I  have  witnessed,  lead  me  to  the 
opinion  that  continuance  of  the  present  unhampered  license  to  pollute  can  only  lead  to 
disaster.  When  it  can  be  shown  that  even  now  the  condition  of  the  harbor  in  summer 
is  obviously  unclean,  it  is  only  a  question  of  time  when  an  ever-increasing  population 
discharging  an  incremental  amount  of  sewage  and  trade  waste  into  what  must  be  prac- 
tically a  stationary  volume  of  harbor  water  will  convert  into  a  nuisance  what  should 
be  one  of  the  brightest  and  best  of  the  city's  possession. 

One  of  my  first  actions  in  prosecuting  this  study  was  to  investigate  the  condition  of 
the  harbor  water,  and  even  in  the  end  of  November  I  found  at  several  places  a  slight 
smell  of  sewage.  In  ferrying  across  the  river  between  92d  Street  and  Astoria  I  ob- 
served innumerable  particles  of  paper  and  even  pieces  of  excrementitious  matter  in  the 
water.    Sea  gulls  indicated  where  the  public  sewers  debouched  directly  into  the  river. 

In  many  places  in  the  East,  the  Harlem  and  the  Hudson  rivers,  the  Gowanus  and 
WTallabout  bays,  visible  evidence  of  the  presence  of  sewage  was  only  too  apparent. 
Near  the  Battery  I  saw  food  which  had  just  been  unloaded  from  a  boat  that  was  moored 
in  what  looked  more  like  sewage  than  clean  water.  At  another  place  (Gowanus 
canal)  I  witnessed  the  ebullition  of  gas,  apparently  arising  from  septicized  sewage 
sludge.  Large  flows  of  greasy  sleek  and  debris  were  to  be  seen  at  frequent  intervals. 
Open  ends  of  sewers  spewing  their  filthy  contents  into  the  rivers  are  of  much  too  fre- 
quent occurrence. 

One  and  all  demonstrate  the  same  lesson — that  the  time  has  arrived  when  a  standard 
of  cleanness  should  be  set  and  maintained.  If  such  conditions  were  offensive  in  No- 
vember and  December,  it  is  obvious  that  they  must  be  worse  in  the  hot  seasons  of  the 
year.  Of  course,  offensiveness  to  sight  and  smell  do  not  necessarily  constitute  a  nui- 
sance which  is  dangerous  to  health,  but  as  no  self-respecting  community  would  tolerate 
streets  that  were  rarely  scavenged  because  no  injury  to  health  could  be  traced  to 
them,  no  port  of  the  first  rank  should  permit  excrement  paper,  straw  and  grease  to  flow 
to  and  fro  on  the  surface  of  the  chief  highway  into  the  city  because  it  could  not  be 
proved  that  a  human  being  had  died  as  the  result. 

The  Proper  Standard  of  Cleanness.  The  standard  of  cleanness  which  you  suggest, 
and  which  I  heartily  approve,  should  be  reasonably  but  strictly  enforced.*   Liquid  pol- 

*Report  Metropolitan  Sewerage  Commission  of  New  York,  August,  1912,  page  70. 

1.  Garbage,  offal  or  solid  matter  recognizable  as  of  sewage  origin  shall  not  be  visible  in  any  of  the 
harbor  waters. 

2.  Marked  discoloration  or  turbidity,  due  to  sewage  or  trade  wastes,  effervescence,  oily  sleek,  odor  or 
deposits,  shall  not  occur  except  perhaps  in  the  immediate  vicinity  of  sewer  outfalls,  and  then  only  to 
such  an  extent  and  in  such  places  as  may  be  permitted  by  the  authority  having  jurisdiction  over  the  sani- 
tary condition  of  the  harbor. 

3.  The  discharge  of  sewage  shall  not  materially  contribute  to  the  formation  of  deposits  injurious  to 
navigation. 

4.  Except  in  the  immediate  vicinity  of  docks  and  piers  and  sewer  outfalls,  the  dissolved  oxygen  in  the 
water  shall  not  fall  below  3.0  cubic  centimeters  per  litre  of  water. t  Near  docks  and  piers  there  should 
always  be  sufficient  oxygen  in  the  water  to  prevent  nuisance  from  odors. 

5.  The  quality  of  the  water  at  points  suitable  for  bathing  and  oyster  culture  should  conform  substantially 
as  to  bacterial  purity  to  a  drinking  water  standard.  It  is  not  practicable  to  maintain  so  high  a  standard 
in  any  part  of  the  harbor  north  of  the  Narrows  or  in  the  Arthur  Kill.  In  the  Lower  bay  and  elsewhere, 
bathing  and  the  taking  of  shellfish  cannot  be  considered  free  from  danger  of  disease  within  a  mile  of  a 
sewer  outfall. 

tWith  60  per  cent,  of  sea  water  and  40  per  cent,  of  land  water  and  at  the  extreme  summer  temperature 
of  80  degrees  F.,  3.0  cubic  centimeters  of  oxygen  per  litre  corresponds  to  58  per  cent,  of  saturation. 


184 


REPORTS  OF  EXPERTS 


lution,  though  less  obtrusive,  is  not  loss  in  need  of  prevention,  and  it  is  in  the  interest  of 
the  community  to  see  that  any  recognized  standard  which  may  be  decided  upon  should 
be  conscientiously  adhered  to.  What  the  standard  should  be  is  a  question  which  you 
have  already  submitted  to  a  number  of  well-knoAvn  experts,  and  they  have  all  united 
in  saying  that  the  dissolved  oxygen  in  the  harbor  water  should  not  be  allowed  to  fall 
below  50  per  cent,  or  60  per  cent,  of  the  saturation  limit.  Colonel  Black  and  Professor 
Phelps  suggested  that  it  should  not  be  allowed  to  fall  below  TO  per  cent,  saturation,  and 
this  figure  is  more  in  accordance  with  my  own  view;  indeed,  I  go  further  and  say  that 
an  even  higher  standard  is  feasible  if  the  project  recommended  later  in  this  report  is 
approved  and  given  effect  to. 

The  result  of  289  samples  tested  by  you  for  dissolved  oxygen  in  the  summer  of 
1911  show  clearly  the  polluted  state  of  some  parts  of  the  harbor.  Taking  100  per  cent, 
as  the  saturation  point,  or  the  normal  condition  of  clean  water,  the  following  compari- 


son of  average  figures  speaks  volumes : 

Lower  New  York  bay   98  per  cent. 

Long  Island  Sound  near  Throgs  Neck   96  " 

Hudson  river,  a  few  miles  above  Manhattan  Island   81  " 

Narrows    73  " 

Upper  East  river   71  " 

Kill  van  Kill]   66  " 

Hudson  river  to  north  of  Manhattan  Island   64  " 

Upper  New  York  bay   63  " 

Lower  East  river   55  " 

Newark  bay   54  " 

Harlem  river   42  " 


Average  figures  in  such  a  study  do  not  quite  suffice,  for  as  the  strength  of  a  chain 
is  the  weakest  link,  so  the  lowest  figures  obtained  (30  per  cent,  at  the  lower  end  of  the 
Harlem  in  July,  1911)  indicate  the  danger  conditions  which  sanitarians  would  strain 
every  nerve  to  avert.* 

The  Increasing  Discharge  of  Sewage.  When  one  remembers  that  the  population  of 
New  York  was  only  2,500,000  in  1890,  and  that  in  1905  it  was  4,000,000,  a  careful  esti- 
mate of  its  probable  growth  in  the  future  is  essential  to  arrive  at  a  wise  judgment  in 
the  matter  of  sewage  disposal. 

Estimates  have  been  made  by  several  authorities,  including  Freeman,  who  said  the 


population  in  1940  would  be   7,652,000 

and  Laidlaw,  who  said  it  would  be   8,662,829 

The  New  York  Telephone  Company's  estimate  is   8,747,000 

and  the  Board  of  Water  Supply's  estimate  is   9,258,600 


The  average  of  these  suggest  a  probable  population  of  the  city  in  1940  of  8,580,107, 
a  figure  which  proximates  to  your  own  estimate  of  9,000,000,  which,  be  it  remembered, 
is  based  on  the  ( 'ensus  figure  of  1910,  and  on  this  account  is  more  likely  to  be  accurate. 

The  prospective  population  which  should  be  reckoned,  however,  is  not  9,000,000, 
but  12,000,000,  the  population  of  the  metropolitan  area.  The  question  as  to  what  ex- 
tent the  harbor  is  likely  to  be  burdened  with  impurities  in  1910,  assuming  that  nothing 
is  done  in  the  interval,  depends  on  population  more  than  anything  else,  and  whether 


"The  percentage  of  oxygen  fell  still  lower  in  1912.  The  average  for  the  year:  Hudson  river  off  Pier  A,  55 
per  cent.;  Narrows,  70  per  cent.;  Kill  van  Kul),  65  per  cent.;  Upper  New  York  bay,  64  per  cent.;  Lower 
East  River,  47  per  cent. 


EEPORT  OF  JOHN  D.  WATSON 


185 


that  population  is  located  north,  south,  east  or  west  of  the  harbor  makes  no  difference. 
Artificial  boundaries,  therefore  (state  or  other),  are  obviously  not  so  important  to  the 
issue  as  watershed,  and  far  fetched  as  it  may  appear  to  be  at  first  sight,  the  manner  of 
disposing  of  the  sewage  of  the  City  of  Albany  and  every  other  populous  place  built 
and  to  be  built  on  the  banks  of  the  Hudson  will  materially  affect  the  problem  under 
consideration.  This  will  be  apparent  if  it  is  conceded  that  the  recuperative  influence 
of  the  harbor  depends  very  largely  upon  the  purity  or  otherwise  of  the  Hudson  as  it 
enters  New  York  City. 

The  act  of  assimilation  can  be  carried  on  only  in  the  presence  of  oxygen,  and  it 
i?  therefore  essential  to  conserve  that  oxygen  as  much  as  possible. 

The  table  which  I  have  quoted  to  show  the  relative  state  of  purity  at  various 
specified  places  as  measured  by  percentage  of  loss  of  oxygen  is  eloquent  condemnation 
of  the  existing  system,  a  condemnation  which  is  only  partially  mitigated  by  the  natu- 
rally and  wonderfully  even  admixture  of  the  harbor  water  as  shown  by  the  voluminous 
observations  you  have  made. 

In  studying  this  question  the  fact  that  the  volume  of  sewage  must  increase  con- 
stantly has  to  be  set  in  juxtaposition  with  the  fact  that  the  clean  water  from  whence 
the  oxygen  is  derived  must  remain  very  much  the  same  in  all  time.  Nor  should  the 
floating  population  as  represented  by  the  trade  of  the  harbor  be  ignored.  This  is  cer- 
tainly a  difficult  problem,  and  I  fear  it  will  be  impossible  to  exclude  sewage  from  this 
source  altogether;  it  is  the  more  important,  therefore,  that  the  authorities  deal  effect- 
ively with  the  sewage  from  the  stationary  population  which  is  under  control. 

Cleanness,  a  Commercial  Necessity.  On  the  day  I  arrived  in  New  York  the  news- 
papers referred  to  a  remarkable  speech  by  the  Mayor  on  the  subject  of  the  growth  of 
imports  and  exports  at  several  harbors  of  the  United  States.  The  occasion  for  this 
speech  was  the  144th  anniversary  of  the  organization  of  the  Chamber  of  Commerce,  and 
it  was  shown  that  the  increase  of  trade  at  New  York  was  far  and  away  greater  than  at 
any  other  port  in  the  country. 

Since  1898  the  increase  at  the  port  of  New  York  was   Ill  per  cent. 

"    "     "     "  Philadelphia  was   75 

"    "     "     "  Boston  was   17 

u       u      u  decrease  "    "     "     "  Baltimore  was   7 

All  the  facts  and  considerations  of  the  case  lead  me  to  the  conclusion  that  the 
community  must  bestir  itself  if  it  would  retain  for  its  harbor  the  good  name  which  is 
now  associated  with  it.  Let  the  cases  of  Marseilles  and  Glasgow  be  a  warning.  Many 
years  ago  the  Clyde  became  so  foul  that  even  poor  trippers  declined  to  board  pleasure 
steamers  nearer  to  the  Broomielaw  than  Greenock,  several  miles  down  the  river.  Since 
that  time  large  sums  of  money  have  been  spent  on  sewage  disposal  works,  but  the  bad 
reputation  justly  associated  with  the  name  of  the  Glasgow  harbor  years  ago  will  not 
be  got  rid  of  for  many  years  to  come.  Every  port  has  a  duty  to  every  other  port,  which 
if  faithfully  observed  would  inaugurate  a  state  of  things  that  would  go  far  to  lessen  the 
duties  of  port,  sanitary  and  quarantine  officers. 

Discussion  of  the  Metropolitan  Sewerage  Commission's  Four  Schemes  for  the 

Purification  of  the  Harbor 

What  then  is  the  most  practicable,  the  most  hygienic  and  the  most  permanently 
economical  scheme  to  adopt?   I  have  studied  Ihe  various  schemes  put  forward  in  the 


186 


REPORTS  OF  EXPERTS 


admirable  reports  which  you  have  sent  to  the  Mayor  of  the  City  since  September,  1911.* 
Although  the  schemes  enumerated  in  your  reports  may  not  have  exhausted  every 
phase  of  what  you  term  the  art  of  sewage  purification,  yet  in  my  view  you  have  consid- 
ered every  method  applicable  to  New  York  which  can  be  regarded  as  reasonably 
practicable. 

Scheme  1  refers  to  the  application  of  sewage  to  land.  (Broad  irrigation  and 
intermittent  filtration.) 

Scheme  2  refers  to  filtration  of  sewage  through  biological  filters  (bacteria 
beds. 

Scheme  3  refers  to  treatment  of  sewage  by  a  variety  of  methods  at  various 
points  of  outfall,  each  case  being  adapted  to  its  special  circumstances,  and  the 
ultimate  disposal  of  partially  purified  liquid  into  the  nearest  water  course. 

Scheme  4  refers  to  the  conveyance  of  a  large  part  of  the  sewage  out  to  the 
Atlantic  ocean  with  the  minimum  of  treatment. 

Scheme  1 

Application  op  the  Sewage  to  Land 

The  popularity  of  irrigation  as  a  means  of  purifying  sewage  is  on  the  wane,  chiefly 
owing  to  the  extensive  area  required  and  the  unsuitability  of  the  land  available. 

The  Berlin  farm,  which  is  the  largest  in  Europe,  continues  to  do  good  work.  The 
largest  farm  in  England  was  at  Birmingham,  but  some  years  ago  when  land  could  no 
longer  be  obtained  for  less  than  three  times  its  agricultural  value,  the  authorities 
abandoned  irrigation  in  favor  of  the  intensive  method  of  purification  on  bacteria  beds. 
The  largest  farm  in  France  is  at  Paris,  and  there  also  the  authorities  contemplate  a 
change  of  method  whenever  it  is  necessary  to  increase  the  purification  plant. 

Where  all  the  conditions  are  favorable,  irrigation  is  undoubtedly  successful  as  a 
vehicle  of  purification,  and  one  which  generally  yields  consistently  good  effluents,  but  in 
New  York  the  farm  would  be  so  colossal  in  extent  that  the  conditions  would  not  be 
invariably  favorable.  The  available  land  is,  I  fear,  limited  to  Long  Island,  the  area 
required  would  exceed  150  square  miles.  It  would  necessarily  vary  in  its  adaptability 
for  the  purpose,  and  although  the  standard  of  purification  need  not  be  exceptionally 
high  in  view  of  the  large  volume  of  water  into  which  it  would  ultimately  be  discharged, 
it  would  still  be  necessary  to  limit  the  volume  of  sewage  to  10,000  or  12,000  gallons  per 
acre,  unless  a  great  expenditure  for  underdrainage  were  undertaken. 

Sanitary  Objections.  A  great  area  of  land  lying  between  Amityville  and  Quogue 
overlies  one  of  the  sources  of  the  city's  present  water  supply,  and  its  use  for  sewage 
purification  would  be  a  potential  source  of  plague  which  no  one  would  care  to  risk. 

The  mere  saturation  of  150  square  miles  of  land  with  sewage  would  be  a  menace  to 
the  inhabitants  obliged  to  reside  in  the  district  and  would  be  sure  to  produce  mal-odors 
during  certain  states  of  the  atmosphere,  which  would  be  highly  objectionable,  even  if 
they  did  not  markedly  influence  the  health  statistics  of  the  district. 

I  disapprove  of  this  method  of  purifying  New  York  sewage  on  grounds  quite  apart 
from  cost;  nevertheless,  it  is  important  to  note  that  it  is  the  most  costly  of  the  schemes 
brought  forward,  and  would  probably  amount  to  $1S0,000,000 ;  this,  too,  assumes  that 
land  could  be  acquired  for  about  |500  per  acre — a  somewhat  sanguine  estimate. 

'Metropolitan  Sewerage  Commission's  Preliminary  Reports  on  the  Disposal  of  New  York's  Sewage,  I 
to  V  inclusive. 


REPORT  OF  JOHN  D.  WATSON 


187 


Scheme  2 
Oxidation  in  Bacteria  Beds 

The  epoch-making  experiments  of  the  Massachusetts  State  Board  of  Health  have 
led  to  the  adoption  of  what  has  been  called  the  intensive  method  of  purification.  By 
this  biological  filters  are  made  to  take  the  place  of  land,  and  in  your  case  would  prob- 
ably purify  140  times  as  much  sewage  as  the  same  area  of  land  under  irrigation.  It  is 
a  method  which  is  almost  invariably  adopted  in  modern  works  which  are  located  some 
distance  from  sea,  lake  or  river. 

To  carry  the  whole  or  the  major  portion  of  the  New  York  sewage  to  Barren  Island 
and  then  treat  it  on  bacterial  filters  would  be  costly,  and  could  only  be  justified  if  it 
could  be  shown  that  a  specially  good  affluent  is  essential  at  the  point  of  discharge. 

As  the  oyster  beds  will  probably  depreciate  in  value  as  the  population  of  the  dis- 
trict increases,  it  would  not  be  wise  on  this  account  alone  to  incur  the  expense  of  this 
operation,  more  particularly  as  it  is  now  admitted  on  all  hands  that  the  passage  of  sew- 
age through  a  biological  filter  does  not  necessarily  deprive  it  of  pathogenic  organisms, 
and  in  order  to  protect  the  oysters  from  the  attack  of  a  stray  typhoid  bacillus  it  would 
in  this  case  be  necessary  to  sterilize  before  1940  a  quantity  of  sewage  equal  to  about 
700,000,000  gallons. 

Danger  of  Nuisance.  Perhaps  Barren  Island  is  the  very  best  site  available  for 
placing  an  installation  of  percolating  filters,  but  it  would  appear  as  if  Jamaica  bay 
were  on  the  eve  of  great  developments,  and  that  Barren  Island  would  not  for  long 
be  the  isolated  place  it  now  is.  I  regard  it  as  of  the  utmost  importance  to  establish 
sewage  purification  works  where  they  are  not  likely  to  become  a  nuisance,  and  I  have 
grave  doubts  about  the  wisdom  of  placing  so  vast  an  area  as  1,000  acres  of  bacteria 
beds  so  near  to  an  industrial  center  as  they  would  be  on  Barren  Island.  In  contem- 
plating such  a  scheme  there  is  a  factor  which,  should  be  taken  into  account,  and  that 
is  the  after  effects  of  the  evaporation  of  so  much  foul  liquid  as  there  must  necessarily 
be  from  such  an  area  of  filters. 

In  1911,  when  the  summer  weather  in  England  was  warmer  than  usual,  there  were 
complaints  of  smell  nuisance  at  Henley,  where  the  sewage  is  of  about  the  same  strength 
as  the  average  American  sewage,  and  where  it  is  distributed  over  rectangular  percola- 
ting beds  by  mechanical  distributors  moving  backwards  and  forwards.  Complaints 
were  also  made  by  residents  near  the  Birmingham  works,  where  the  sewage  is  sprayed 
over  the  beds  by  fixed  nozzles. 

The  chief  lesson  to  be  learned  from  the  1911  experience  is  that  an  increase  of  flies 
is  to  be  looked  for  in  the  neighborhood  of  bacteria  beds  in  hot  weather,  and  that  objec- 
tional  smell  adjacent  to  them  is  more  pronounced  during  prolonged  hot  weather  than 
at  other  times,  e.  g.,  seasons  like  the  average  English  summer,  when  the  temperature 
rarely  exceeds  65°  Fahr.  in  the  shade.  But  a  much  more  serious  drawback  to  a  great 
area  of  bacteria  beds  during  spells  of  prolonged  hot  weather  is  the  formation  of 
vaporous  "clouds,"  due  to  the  evaporation  of  sewage.  These  clouds  appear  to  form 
over  the  beds  in  quiet  weather.  They  rise  to  some  distance  above  the  earth,  and  at  sun- 
down, when  the  earth  begins  to  cool,  they  return  not  alone  as  refreshing  dew,  but  with 
offensive  odor.  If  this  occurred  only  in  the  vicinity  of  the  bacteria  beds,  where  the 
land  is  generally  less  valuable  than  at  some  distance,  it  would  not  be  so  serious  in  its 
consequences,  but  it  generally  occurs  at  some  distance  from  the  bacteria  beds,  the  di- 
rection and  distance  depending  upon  the  tendency  and  the  velocity  of  the  wind. 


188 


REPORTS  OF  EXPERTS 


Cost.  Of  course,  it  is  only  the  nial-odorous  element  in  sewage  that  makes  this  phe- 
nomenon noticeable;  evaporation  from  clean  water  would  act  precisely  in  a  similar 
manner,  but  it  would  manifest  itself  in  welcome  dew  on  the  grass.  This  led  me  to  adopt 
at  Birmingham  the  use  of  hypochlorite  of  calcium  with  excellent  results,  but  the  cost 
would  be  a  serious  matter  where  700,000,000  gallons  had  to  be  treated  each  day;  indeed, 
(lie  bare  probability  of  hypochlorite  of  either  calcum  or  sodium  (and  the  latter  is  even 
more  effective)  having  to  be  used  frequently,  would  be  sufficient  in  itself  to  retard  the 
adoption  of  a  scheme  which  would  be  many  times  as  large  as  anything  now  in  exist- 
ence.  It  is  obvious  that  climate  is  of  paramount  importance. 

The  initial  cost  of  1,000  acres  of  biological  filters  to  deal  with  700,000,000  gallons 
of  sewage  would  be  not  less  than  .$140,000,000,  apart  from  maintenance  charges.  Alto- 
gether, I  agree  that  the  Commission  would  not  be  justified  in  espousing  this  scheme 
as  the  best  available  for  New  York. 

Scheme  3 

Local  Treatment  Works  and  Outfalls 

It  is  probably  not  far  from  the  truth  to  say  that  the  only  purification  of  organic 
matter  known  to  nature  is  an  oxidizing  one,  which  is  brought  about  indirectly  by  the 
agency  of  bacteria,  but  whether  the  vehicle  by  which  the  process  is  brought  to  fruition 
is  the  irrigation  farm,  the  biological  filter  or  dilution  with  large  volumes  of  clean  water, 
the  "combustion"  process  is  practically  the  same. 

To  protect  the  harbor  from  pollution  it  is  neither  essential  to  confine  the  purifying 
process  to  one  method  nor  to  one  locality,  but  whether  it  is  expedient  or  wise  to  con- 
struct dozens  of  sewage  purification  plants  in  and  around  New  York  is  an  entirely 
different  matter.  Sewage  from  the  various  districts  delineated  on  the  plans  could  be 
sufficiently  treated  to  admit  of  being  discharged  in  the  adjacent  waters  without  cre- 
ating a  nuisance,  but  in  some  cases  the  treatment  would  have  to  be  very  circumscribed, 
and  a  greater  burden  would  be  placed  upon  the  assimilating  powers  of  the  waters  than 
they  ought  to  be  called  upon  to  bear. 

Essential  Details.  It  is  unnecessary  for  me  to  refer  in  detail  to  the  various  outfalls 
that  would  be  required  under  this  scheme.  Suffice  it  to  say  that  I  have  examined 
many  of  the  suggested  sites,  with  the  invariable  result  that  they  all  appear  to  me  to 
have  been  chosen  with  great  judgment  and  engineering  skill.  It  is  more  than  prob- 
,  able,  however,  that  if  Scheme  3  finds  most  favor,  the  sites  shown  on  the  plans,  and  re- 
ferred to  in  your  reports,  may  have  to  be  altered  when  negotiations  for  the  purchase  of 
those  sites  are  begun ;  this  will  be  found  to  be  specially  true  in  the  case  in  the  nineteen 
outfalls  on  Manhattan  Island. 

Under  this  scheme  it  would  be  necessary  to  lay  sewers  towards  an  outfall  which 
would  terminate  in  the  deepest  water  available  in  the  vicinity,  where  it  would  be  dis- 
persed by  a  complete  system  of  moderate  sized  outlets  so  placed  as  to  enter  the  stream 
transversely  to  the  flow  and  in  sufficient  number  to  encourage  equal  diffusion.  Each 
outfall  should  be  protected  by  grit  chambers  and  settling  basins  in  duplicate;  the  former 
should  be  provided  with  every  appliance  requisite  to  remove  solids  of  large  size,  road 
grit,  rags,  etc. 

Disposal  of  the  Sludge.  The  basins  should  be  built  so  as  to  induce  the  sludge  ar- 
rested by  mechanical  or  chemical  precipitation  (as  may  be  found  best  under  circum- 
stances which  vary  considerably  at  different  outfalls)  to  collect  at,  say,  the  apex  of 


REPORT  OF  JOHN  D.  WATSON 


189 


an  inverted  cone  or  pyramid,  and  the  sludge  collected  should  be  pumped  daily  into 
steamboats  built  for  the  purpose  and  removed  well  out  to  sea.  This  system  of  getting 
rid  of  sludge  is  well  suited  to  a  scheme  which  would  have  all  its  sludge  tanks  within 
easy  reach  of  navigable  water. 

In  my  view  the  sludge  should  be  removed  daily  so  as  to  obviate  smell  nuisance. 
The  only  alternative  would  be  to  septicize  the  sludge  in  Emscher  tanks,  but  this  would 
mean  large  and  deep  tanks,  which  would  be  incompatible  with  the  conditions  obtain- 
ing at  some  of  the  outfalls,  particularly  those  in  Manhattan,  where  the  sludge  tanks 
would  perforce  be  placed  in  the  streets  abutting  on  the  bulkhead  and  shore  lines.  The 
experience  of  the  engineers  at  London,  Glasgow  and  Manchester  puts  at  rest  any  doubt 
as  to  the  practicability  of  removing  unsepticized  sludge  by  steamboat,  but  there  is 
nothing  equally  convincing  to  show  that  if  it  were  in  a  state  of  active  fermentation  it 
could  be  so  easily  removed  and  so  quickly  lost  to  view  when  dropped  into  the  ocean. 

Only  Limited  Treatment  Practicable  at  Wards  Island.  If  such  a  scheme  as  this 
were  to  be  carried  out,  its  weakness  would  probably  become  apparent  first  at  Wards 
Island,  where  302,000,000  gallons  of  sewage  will  have  to  be  treated  daily  in  1910.  The 
reasons  I  have  given  against  the  establishment  of  a  great  area  of  filter  beds  at  Barren 
Island  are  even  more  potent  when  applied  to  Wards  Island,  so  that  either  mechanical 
or  chemical  precipitation  would  in  the  present  state  of  knowledge  have  to  be  resorted 
to,  and  neither  process  is  efficient  enough  to  warrant  me  in  suggesting  that  such  a 
volume  of  effluent  could  be  discharged  into  the  East  river  without  unduly  drawing 
upon  the  oxygen  of  the  harbor  water. 

One  of  the  leading  factors  in  considering  the  Wards  Island  problem  is  the  fact 
that  the  river,  so  called,  is  without  a  continuous  flow  of  fresh  water  towards  the  sea; 
any  sewage  effluent,  therefore,  would  have  to  rely  upon  admixture  with  the  water  of  a 
tide  in  order  to  obtain  the  necessary  supply  of  oxygen  to  obviate  putrefaction,  and  con- 
sidering the  volume  available  for  this  purpose,  I  am  doubtful  whether  the  results 
would  be  acceptable  at  all  seasons  of  the  year.  Of  course,  the  sedimentation  process, 
including  screening  and  sludge  removal  to  sea,  or  that  process  plus  the  addition  of  a 
coagulant  to  help  mechanical  precipitation,  do  not  exhaust  the  great  sources  of  power 
in  nature,  and  it  is  quite  possible  that  we  may  lief  ore  many  years  are  over  realize  the 
practicability  of  electrolyzed  sea  water.  Your  laboratory  experiments  stimulate  me 
with  hope,  but  I  cannot  in  the  present  state  of  my  knowledge  recommend  them  as  a 
practical  solution  of  the  problem. 

Under  this  scheme  there  would  be  many  outlets,  all  of  which  would  require  to  be 
equipped  with  screens,  grit  chambers,  tanks,  and  some  kind  of  treatment  works,  before 
the  effluent  could  be  discharged  and  left  for  the  nearest  water  to  complete  its  purifica- 
tion by  assimilation. 

Scheme  4 

Conveyance  op  a  Large  Part  of  the  Sewage  to  Sea 

The  distinctive  feature  of  this  scheme  is  the  provision  of  subterranean  channels,  or 
great  sewers,  into  which  each  part  of  the  municipality  embraced  within  a  prescribed 
area  would  have  the  indisputable  right  to  discharge  sewage  and  trades  wastes  without 
let  or  hindrance,  knowing  that  the  sewage  would  be  conveyed  right  out  to  the  Atlantic 
ocean.  Nothing  in  the  nature  of  treatment  beyond  arresting  solids  that  would  other- 
wise obstruct  the  pumps  would  be  undertaken  en  route. 

One  important  feature  of  this  scheme  would  be  the  formation  of  an  island  in  the  sea 


190 


REPORTS  OF  EXPERTS 


about  three  miles  south  of  Coney  Island.  The  formation  of  such  an  island  is  by  no 
means  unprecedented,  but  the  idea  of  forming  one  some  miles  from  land  for  the  sole 
purpose  of  treating  sewage  is  a  novelty  in  the  history  of  sewage  purification. 

Scheme  4  involves  pumping  the  sewage,  screening  it,  arresting  a  proportion  of  the 
suspended  solids  in  sedimentation  tanks  to  be  constructed  on  the  island,  and  there- 
after leading  it  by  a  series  of  pipes  into  deep  water  to  secure  effectual  diffusion. 

Having  the  sewage  tanks  on  the  island  would  obviate  the  usual  troublesome  claims 
for  compensation  in  respect  of  depreciation  of  value  of  adjacent  property.  The  island 
could  be  extended  almost  indefinitely  as  occasion  for  extension  arose.  Its  position 
would  be  the  best  possible  from  which  the  superintendent  of  the  works  might  observe 
the  ebb  and  flow  of  the  tide,  and  regulate  the  emptying  of  the  sedimentation  tanks. 

The  Treatment  Necessary.  The  question  of  the  extent  to  which  sedimentation 
should  be  carried  is  one  which  will  gradually  settle  itself.  I  do  not  think  it  will  be 
necessary  to  effect  settlement  until  after  the  first  section  of  the  work  has  been  in  opera- 
tion for  some  time,  but  as  section  after  section  is  completed  it  will  be  found  necessary 
to  arrest  the  solids  in  tanks,  made  with  the  view  of  concentrating  the  sludge  at  the 
bottom  of  either  conical  or  pyramidal  pockets  placed  at  an  elevation  to  induce  the 
sludge  to  flow  by  gravitation. 

The  precise  site  of  the  proposed  island  will  require  careful  consideration,  but 
that  shown  on  your  plan  appears  to  be  feasible.  Excepting  rip-rap  for  the  external  for- 
mation, nearly  all  the  material  for  making  it  can  be  readily  and  cheaply  obtained, 
chiefly  from  (1)  ddbris  or  spoil  from  building  sites  which  at  present  is  dumped  into 
the  ocean;  (2)  spoil  from  the  tunnels  and  terminating  shaft,  and  (3)  sand  pumped 
from  the  adjacent  sand  banks. 

The  Progressive  Steps  in  this  Scheme.  The  first  step  to  be  taken  if  this  scheme  is 
entertained  is  to  collect  sewage  from  those  parts  of  Manhattan  and  Brooklyn  which 
border  on  the  East  river,  convey  it  by  tunnel  to  a  central  pumping  station  at  Wall- 
about,  near  the  Navy  Yard,  and  lift  it  to  another  pumping  station  at  Sheepshead  bay, 
whence  it  would  be  conveyed  to  the  projected  island  for  disposal. 

The  population  of  the  districts  to  be  served  at  first  by  this  instalment,  and  the  dry 
weather  flow  of  sewage  pertaining  thereto,  are  as  follows : 

Sewage, 

District  Population,  1915    Gallons  per  Day 

Manhattan   680,000  99,000,000 

Brooklyn   732,000  104,000,000 


Total,  1,412,000  203,000,000 
The  Wallabout  pumping  station  would  lift  133,000,000  gallons  coming  from  the 
north  18  feet  in  height,  and  70,000,000  gallons  from  the  south  33  feet  in  height,  and  the 
Sheepshead  bay  station  203,000,000  gallons  about  38  feet  in  height. 

This  instalment  could  be  executed  for  about  $18,000,000,  which  would  entail  for  in- 
terest (at  4!/2%  for  50  years),  together  with  maintenance  charges,  an  annual  payment 
of  $1,500,000,  but  I  do  not  recommend  you  to  limit  the  size  of  the  tunnel  to  a  carrying 
capacity  of  400,000,000  gallons,  or  about  twice  the  dry  weather  flow,  as  I  believe  the 
second  instalment  of  the  scheme  should  be  undertaken  soon  after  the  completion  of  the 
first. 

The  second  instalment,  I  apprehend,  would  be  to  couple  up  the  intercepting  sewer 
which  would  serve  the  Jamaica  Bay  Division,  shown  on  the  plan  accompanying  your 
report  to  the  Mayor,  dated  November,  1911. 


REPORT  OF  JOHN  D.  WATSON 


191 


The  third  instalment  of  the  work  should  bring  the  sewage  of  the  Upper  East  river 
and  Harlem  Division  into  the  system,  and  tho  fourth  would  take  in  Richmond  and  as 
much  of  New  Jersey  as  may  be  determined. 

In  my  opinion  all  the  intercepting  sewers  should  be  capable  of  conveying  not  less 
than  twice  the  dry  weather  flow  before  storm  water  is  shed  into  the  nearest  water- 
course; this  would  correspond  favorably  with  the  English  practice  of  conveying  six 
times  the  dry  weather  flow,*  or  rather  less  than  200  gallons  per  head  per  day. 

Need  of  a  Permanent  Sewage  Disposal  Commission 

Of  the  four  projects  thus  briefly  outlined  as  possible  schemes  for  adoption,  I  have 
a  decided  preference  for  Scheme  4.  I  admit  that  Scheme  3  is  feasible,  but  it  lacks 
finality  and  possesses  features  which  should  be  avoided  when  possible,  c.  g.,  the 
numerous  outfalls  and  the  drawbacks  attaching  to  them  in  the  eyes  of  the  general 
public,  their  not  invariably  suitable  locations,  and  their  inevitable  increase  in  num- 
ber as  the  population  increases.  What  influences  me  most  in  favor  of  Scheme  4  is  the 
conviction  that  where  it  is  possible  to  remove  the  bulk  of  the  sewage  of  New  York  en- 
tirely away  from  its  source  to  the  ocean  it  should  be  so  removed,  although  the  cost  may 
be  somewhat  higher  than  it  would  be  under  a  project  like  Scheme  3. 

In  a  great  city  where  such  public  services  as  water  supply,  sewerage  and  sewage 
disposal  are  indispensable,  and  where  several  self-governing  municipalities  benefit  by 
the  common  service,  it  is  essential  in  the  interests  of  good  and  economical  administra- 
tion that  there  should  be  a  permanent  commission,  with  jurisdiction  over  the  whole 
area.  Such  a  general  commission  from  its  very  constitution  is  enabled  to  deal  with 
questions  more  comprehensively  than  local  boards,  commissions,  departments  or 
bureaus  can  do.  Probably  an  example  of  what  I  mean  may  be  found  by  reference  to 
the  endeavor  to  improve  the  insanitary  conditions  of  the  Gowanus  canal,  where  a 
local  sewer  bureau  tried  to  remedy  a  nuisance  by  conveying  a  stagnant,  putrid  liquid 
from  one  locality  to  another  in  the  same  neighborhood.  No  doubt  the  bureau  did  the 
only  thing  available  to  them  at  the  time,  but  they  were  obviously  restricted  in  their  out- 
look, and  were  forced  by  circumstances  to  mitigate  rather  than  remedy  the  evil, 
whereas  if  it  had  been  possible  for  them  to  order  the  polluted  waters  of  the  canal  to 
be  conveyed  beyond  the  municipal  boundaries  to  the  ocean  the  evil  would  have  been 
effectively  remedied.  A  municipal  engineer's  work  is  often  unfairly  criticized  because 
the  effects  of  being  hemmed  in  by  surrounding  boroughs  is  not  adequately  appreciated. 
Administrative  questions,  like  sewerage,  are  not  invariably  united,  but  here  they  should 
be  under  one  commission  or  board,  and  it  is  with  the  object  of  devising  a  workable 
scheme  for  keeping  the  harbor  free  from  solid  as  well  as  liquid  impurities  that  I  sug- 
gest the  formation  of  a  commission  to  be  entrusted  with  the  duty  of  making  and  keep- 
ing pure  (or  reasonably  pure)  the  national  waters. 

Proper  Functions  of  a  Permanent  Commission.  The  constitution  of  such  a  com- 
mission would  have  to  be  carefully  framed  by  those  who  are  well  versed  in  existing 
statutes  and  interstate  law,  but  I  venture  to  suggest  one  or  two  points  which  should  be 
carefully  embodied  in  the  constitution. 

The  whole  responsibility  for  maintaining  clean  waters  within  the  prescribed  area 
should  rest  upon  the  commission,  and  they  should  have  all  necessary  power  to  enforce 
their  regulations. 

"For  comparison  between  English  and  American  sewage,  See  Preliminary  Report  VI,  of  the  Metropolitan 
Sewerage  Commission  of  New  York,  January,  1913. 


192 


REPORTS  OP  EXPERTS 


The  commission  should  be  responsible  for  the  design  of  all  intercepting  sewers, 
pumping  stations,  tanks,  outfalls,  etc.,  essential  for  the  construction  of  a  complete  in- 
stallation of  sewerage  and  sewage  disposal  works.  The  board  should  also  be  made 
responsible  for  the  construction  of  these  works  and  for  their  subsequent  maintenance. 

Each  borough  or  municipality  must  have  the  same  right  to  connect  to  an  inter- 
cepting sewer  or  sewers  that  they  now  have  to  discharge  sewage  into  harbor,  river  or 
watercourse. 

The  commission  should  be  charged  with  the  duty  of  seeing  that  pollution,  which 
must  be  inevitable  until  the  intercepting  sewers  or  subterranean  tunnels  are  all  built 
and  connected  to  the  ocean  outfall,  does  not  increase,  even  although  it  should  be  neces- 
sary to  construct  temporary  works  for  the  purpose. 

The  joint  board  or  commission  should  have  ample  power  to  decide  whether  an  in- 
tercepting sewer  or  any  other  work  is  required,  and  to  allocate  the  cost  of  construction 
to  the  users.  It  should  also  have  power  to  regulate  by  by-laws,  or  otherwise,  every- 
thing which  pertains  to  the  keeping  clean  of  the  harbors,  rivers,  canals  or  watercourses 
within  the  area  for  which  it  is  responsible.  If  it  is  usual  to  give  such  commissions 
rating,  borrowing  or  financial  powers,  the  board  should  be  so  empowered. 

In  recommending  the  adoption  of  Scheme  4  it  is  not  to  be  assumed  that  I  advocate 
its  complete  execution  at  once.  If  I  have  succeeded  in  presenting  the  whole  project 
correctly,  it  will  be  apparent  to  all  that  the  dominating  factor  is  and  must  continue  to 
be  the  condition  of  what  I  have  called  the  national  waters.  As  it  stands  at  present,  the 
putrefactive  liquid  entering  them  increases  daily;  their  power  of  oxidizing  foul  liquid 
is  practically  stationary,  and  as  every  sewer  is  diverted  to  the  Atlantic  ocean  by  being 
coupled  up  to  the  system  under  Scheme  4,  their  condition  will  improve.  I  do,  however, 
advocate  progressive,  consistent  advancement  until  the  completion  of  the  scheme  be 
attained,  which  I  hope  will  be  not  later  than  1925. 

Necessity  for  Immediate  Action 

I  cannot  say  too  distinctly  that  there  is  need  for  immediate  action.  The  nature 
and  extent  of  the  tunnel  work  bars  haste  and  precludes  all  chance  of  redeeming  lost  op- 
portunities; therefore  no  opportunities  should  be  lost. 

Generally,  I  am  in  sympathy  with  the  plans  you  have  prepared ;  particularly  do  I 
espouse  what  you  call  Project  1  as  the  first  step  to  be  taken.  There  should,  however, 
be  a  comprehensive  plan  matured  if  possible  in  conjunction  with  the  engineers  of  the 
several  sewer  bureau,  which  will  indicate  how  every  link  of  the  complete  scheme  will 
be  caught  up  in  regular  progressive  stages.  This  is  the  more  important  as  there  might 
be  more  or  less  prolonged  intervals  between  each  successive  stage. 

It  will  probably  cost  not  less  than  $100,000,000  to  complete  Scheme  4,  undoubtedly 
the  largest  sum  ever  contemplated  for  such  a  purpose,  but  no  scheme  has  hitherto  been 
designed  for  the  service  of  12,000,000  people.  Many  small  towns  have  spent  more  per 
capita  than  this  estimate  implies,  and  frequently  all  they  gained  was  the  removal  of  a 
liquid  which  possessed  potential  elements  of  plague.  The  citizens  by  approving  the 
conveyance  of  all  the  sewage  to  the  Atlantic  will  gain  that  and  more,  for  they  will  at 
once  purify  their  harbor  and  rivers,  which  never  will  cease  to  be  the  most  priceless 
and  most  striking  physical  characteristic  of  New  York. 

Comparison  with  European  Undertakings.  If  one  were  to  attempt  a  comparison 
between  the  cost  of  the  sewerage  systems  of  European  capitals  and  what  is  now  pro- 
posed for  New  York,  the  great  disparity  between  the  quantities  of  potable  water  used 


REPORT  OF  GEORGE  W.  FULLER 


193 


b\  the  inhabitants  of  cities  of  the  Eastern  and  Western  Hemispheres  would  arrest  at- 
tention. The  world  has  been  startled  by  the  magnitude  of  your  water  schemes.  Any 
European  city  would  have  regarded  114  gallons  per  capita  as  an  extravagant  allow- 
ance, yet  this — which  is  equal  to  a  daily  supply  of  500,000,000  gallons — is  what  is  now 
obtained  from  the  Croton  works  alone,  but  rather  than  curtail  that  supply,  or  do 
anything  which  might  be  interpreted  to  favor  a  limited  use  of  water  for  public  health 
purposes,  the  authorities  determined  to  carry  out  a  gigantic  scheme  to  obtain  another 
500,000,000  gallons  of  water  per  day,  this  time  from  the  Catskill  mountains.  The  mag- 
nitude of  the  undertaking  and  the  aggregate  cost  of  bringing  in  1,000,000,000  gallons 
per  day  will  place  the  New  York  water  supply  in  a  category  by  itself  when  a  history  of 
the  world's  great  water  works  comes  to  be  written. 

The  consumption  of  water  has  a  direct  relationship  to  a  city's  sewerage  system  as 
regards  cost,  and  it  is  incumbent  upon  an  engineer  in  recommending  a  scheme  to  sat- 
isfy himself  that  it  is  not  only  sound  as  an  engineering  proposition,  but  that  it  is  finan- 
cially possible.  The  facts  I  have  brought  to  your  recollection  go  a  long  way  to  show 
that  a  scheme  of  sewage  disposal  which  will  ultimately  cost  $100,000,000  and  involve 
an  annual  outlay  of  $5,000,000  for  the  benefit  of  12,000,000  people  is  not  disproportion- 
ate to  the  requirements  of  the  city.  But  I  have  not  relied  alone  upon  the  example  of  the 
water  works  in  coming  to  this  decision.  The  numerous  public  schools,  seats  of  learn- 
ing, public  institutions,  colossal  buildings,  wide  streets,  stupendous  bridges  of  unpar- 
alleled width,  not  to  speak  of  railroad,  canal  and  private  enterprise,  the  most  recent  ex- 
amples of  which  may  be  found  in  the  Pennsylvania  and  Grand  Central  stations,  which 
between  them  have  cost  not  less  than  $300,000,000,  all  direct  one's  attention  to  indis- 
putable evidence  of  prosperity  and  progress,  and  to  what  is  of  even  more  importance,  the 
attitude  of  mind  which  shows  that  the  people  have  a  profound  faith  in  the  future  great- 
ness of  their  marvellous  city. 

It  is  quite  unnecessary  to  caution  you  that  all  estimates  of  cost,  so  far  as  they  have 
been  prepared  by  me,  must  be  regarded  as  of  a  tentative  character,  and  should  be 
accepted  cautiously  until  complete  surveys,  detailed  plans  and  sections  are  made,  and 
schedules  of  quantities  drawn  up — nevertheless  they  seem  to  me  to  be  quite  ample  for 
the  work  contemplated. 

I  am,  gentlemen,  your  obedient  servant, 

„  n-i  a.  t  -n-,n  John  D.  Watson. 

Birmingham,  31st  January,  1913. 


SECTION  III 


REPORT  OF  GEORGE  W.  FULLER,  C.  E.# 

To  the  President  and  Members  op  the  Metropolitan  Sewerage  Commission, 
17  Battery  Place,  New  York,  N.  Y. 

Gentlemen:  Pursuant  to  your  request  of  July  29,  1913,  I  beg  to  report  herewith 
my  views  on  the  present  status  of  the  art  of  sewage  disposal  and  on  the  probable  future 
development  of  processes  of  sewage  treatment  with  special  reference  to  New  York  City; 
and  particularly  my  opinion  as  to  whether  the  art  of  sewage  treatment  has  been  devel- 
oped to  such  a  point  as  to  warrant  the  adoption  at  this  time  of  a  definite  policy  and 
plan  for  the  main  drainage  of  this  city,  with  the  necessary  works  for  the  disposal  of 
sewage. 

*  See  also  Appendix  to  Mr.  Fuller's  Report,  pages  213-218,  and  Correspondence  with  Mr.  Fuller,  page  218. 


194 


REPORTS  OF  EXPERTS 


Brief  Summary  of  General  Conclusions 

In  my  judgment  the  art  of  sewage  treatment  has  reached  a  point  such  as  to  war- 
rant at  this  time  the  adoption  of  a  definite  policy  and  general  plan  for  the  main  drain- 
age works  of  New  York  City. 

There  is  between  the  early  advisers  of  the  Commission  and  myself  a  serious  dif- 
ference of  opinion  as  to  the  extent  to  which  the  oxygen  dissolved  in  the  harbor  waters 
may  properly  be  lessened  by  the  digestion  therein  of  clarified  sewage  matters. 

There  is  also  some  uncertainty  as  to  the  extent  to  which  the  harbor  waters  will 
show  improvement  from  the  systematic  prevention  of  sludge  deposits  accumulating  on 
the  harbor  bottom,  particularly  around  slips  and  in  the  vicinity  of  sewer  outlets.  In 
part  this  uncertainty  is  owing  to  difficulties  in  interpreting  the  relation  between  the 
deoxygenating  effects  as  measured  by  laboratory  methods  and  as  actually  encountered 
under  local  conditions  in  practice. 

But  there  is  no  room  for  doubt  as  to  the  correctness  of  the  conclusion  that  the  best 
method  of  disposing  of  New  York  sewage  is  by  mixing  it  promptly  with  sufficient  water 
in  the  neighboring  watercourses,  after  substantial  removal  of  solid  sewage  matters, 
which  now  either  float  on  the  surface  or  subside. 

In  particular  I  agree  with  the  Commission : 

1.  That  visible  evidences  of  sewage  in  the  harbor  waters  should  be  removed  by  first 
subjecting  the  sewage  to  fine  screening  or  sedimentation. 

2.  That  the  subdivision  of  the  city  into  natural  drainage  districts  for  separate 
treatment  is  proper. 

3.  That  the  discharge  of  sewage  should  be  through  submerged  outfalls  into  deep 
water  so  as  to  affect  a  prompt  and  thorough  mixing  wherever  such  submerged  outfalls 
can  be  built  without  serious  objection  and  present  conditions  of  pollution  demand  im- 
provement. 

4.  That  all  construction  should  be  made  to  conform  to  the  general  plan  adopted 
by  a  central  authority. 

Harbor  waters  will  digest,  other  things  being  equal,  more  settled  sewage  than  raw 
sewage.  And  in  my  opinion  the  treatment  of  the  New  York  sewage  as  required  by  fine 
screens  or  sedimentation  will  allow  the  harbor  waters  to  digest  the  sewage  of  a  popula- 
tion materially  greater  than  indicated  by  the  published  opinion  of  the  Commission. 

Some  portions  of  the  harbor  waters,  such  as  Gowanus  canal,  Wallabout  bay,  New- 
town creek,  Harlem  river  and  the  waters  in  the  immediate  vicinity  of  some  of  the 
larger  sewer  outlets  and  over  some  of  the  Manhattan  and  Brooklyn  shore  line  require 
relief  at  once  from  objectionable  conditions  of  sewage  pollution. 

Other  portions  of  the  harbor  waters,  such  as  the  Lower  Hudson  river,  Lower  bay, 
etc.,  have  a  sufficient  volume  of  water  for  dilution  for  many  years  to  come,  and  the  prob- 
lem is  not  a  complicated  one,  provided  the  sewage  is  clarified  by  devices  now  available 
and  is  suitably  distributed  so  as  to  avoid  shore  pollution. 

Uncertainty  as  to  procedure  relates  to  the  intermediate  set  of  conditions  where 
the  available  water  is  neither  obviously  insufficient  on  the  one  hand,  nor  obviously 
ample  on  the  other.    The  Lower  East  river  is  one  of  these  bodies  of  water. 

As  to  the  "outlet  island"  project  for  the  sewage  of  the  Lower  East  river  division, 
as  tentatively  recommended  early  in  1913  by  the  Commission,  I  am  of  the  opinion  that 
the  evidence  now  available  does  not  warrant  the  conclusion  that  this  project  is  the 
proper  one. 

My  views  as  to  residual  oxygen  and  the  significance  of  solid  sewage  matters  lead 


REPORT  OF  GEORGE  W.  FULLER 


195 


me  to  the  opinion  that  local  plants  for  clarifying  the  sewage  now  entering  the  Lower 
East  river  are  entitled  to  much  fuller  consideration  than  I  have  noted  in  the  reports 
which  you  have  published  up  to  this  time.  It  is  my  belief  that  local  clarification 
devices  can  be  installed  along  the  water  front  of  the  Lower  East  river  so  as  to  accom- 
plish all  necessary  relief  from  the  present  uncleanly  conditions.  I  believe  that  the  solu- 
tion of  the  problem  of  this  particular  division  depends  essentially  on  the  matter  of  cost 
and  that  the  program  should  provide  for  that  method  which  will  give  sufficient  im- 
provement to  the  local  waters  at  least  burden  to  the  taxpayers  when  account  is 
taken  both  of  the  investment  and  operating  costs. 

Basis  op  Study 

In  order  to  make  this  report  concise  and  responsive  to  the  New  York  problem,  it  is 
necessary  briefly  to  refer  to  the  more  characteristic  features  resulting  from  the 
methods  now  practiced  in  the  disposal  of  the  sewage  of  New  York  City,  the  needs  as  to 
corrective  treatment  and  the  methods  proposed  for  that  purpose. 

I  have  noted  the  contents  of  the  several  comprehensive  reports  issued  by  the  Com- 
mission and  I  have  also  inspected  personally  the  principal  watercourses  into  which  the 
sewage  of  Greater  New  York  now  discharges. 

Influence  of  New  York  Sewage  on  the  Waters  of  the  Harbor  and  Vicinity 

I  find  that  the  conditions  attending  the  present  discharge  of  the  New  York  City 
sewage  into  the  adjoining  tidal  waters  may  be  briefly  summarized  as  follows : 

1.  Visible  suspended  matter  unquestionably  of  sewage  origin  is  to  be  noted  at 
various  places  in  the  watercourses  into  which  the  city  sewage  is  discharged.  Among 
the  most  conspicuous  places  for  noting  fecal  matters  is  the  Lower  East  river. 

2.  Relatively  large  pieces  of  garbage,  refuse,  driftwood  and  other  sizable  de'bris  are 
to  be  noted  at  various  places.   Only  a  small  part  of  these  originate  in  the  sewage. 

3.  An  oily  film  or  greasy  coating,  sometimes  spoken  of  as  "sleek,"  is  visible  in 
some  places.  It  is  doubtful  whether  such  appearances  exist  to  a  seriously  objectionable 
extent  over  other  than  quite  limited  areas  of  the  New  York  waters. 

4.  Deposits  of  solid  sewage  matters  have  occurred  over  quite  substantial  portions 
of  Upper  New  York  bay,  the  Harlem  river,  in  the  East  and  Hudson  rivers,  in  and 
around  slips  where  sewage  is  discharged  from  the  outer  end  of  neighboring  piers. 

5.  These  deposits  of  sewage  sludge  are  undergoing  decomposition  at  a  more  or 
less  rapid  rate.  In  deep  water  they  do  not  produce  offensive  conditions,  although  they 
are  undoubtedly  robbing  the  overlying  water  of  some  of  its  dissolved  oxygen.  In  the 
vicinity  of  some  of  the  slips,  however,  the  deposits  are  subjected  to  objectionable  putre- 
faction during  the  warmer  months.  Such  putrefactive  decomposition,  with  its  attend- 
ant gasification,  occurs  in  various  degrees  of  intensity  and  at  certain  places  becomes 
objectionable  in  its  offensiveness.  Such  conditions  I  have  noted  in  the  vicinity  of  Go- 
wanus  canal,  TVallabout  channel,  Newtown  creek  and  the  Harlem  river. 

6.  Bathing  in  these  waters  in  the  vicinity  of  the  outlets  of  the  New  York  sewers  is 
an  unsanitary  practice  unless  the  sewage-polluted  waters  are  thoroughly  and  system- 
atically purified  before  use  in  the  bathing  establishments. 

7.  In  the  waters  north  of  the  Narrows  and  at  some  places  south  thereof,  as  well 
as  in  many  locations  in  Jamaica  bay,  the  waters  are  in  all  probability  unsafe  for  use  in 
the  shell-fish  industry. 

8.  Eliminating  questions  of  shell-fish,  bathing  and  perhaps  some  other  means  of 


196 


REPORTS  OF  EXPERTS 


personal  contact  with  the  water,  there  is  no  reason  to  believe  that  the  discharge  of 
sewage  of  New  York  City  into  the  adjoining  waters  has  a  measurable  effect  upon  the 
public  health. 

9.  Analytical  data  indicate  that  there  has  recently  been,  according  to  the  analyses 
made  by  the  Commission,  quite  a  marked  reduction  in  the  atmospheric  oxygen  dis- 
solved in  the  waters  receiving  New  York  City  sewage.  Representative  data  for  the 
years  1909,  1911  and  1913  may  be  summarized  in  tabular  form,  as  follows : 


TABLE  XIX 


Percentage  Saturation  of  Oxygen. 

Divisions  of  Harbor. 

1909 

1911 

1913 

55 

42 

29 

72 

62 

57 

86 

69 

48 

65 

54 

43 

67 

72 

66 

Kill  van  Kull  

79 

70 

65 

83 

76 

69 

Note. — While  not  attempting  to  explain  the  striking  reduction  in  oxygen  content  given  by  these  figures,  it  is 
to  be  noted  that  increase  of  population  is  not  an  adequate  explanation  for  this  reduction. 


10.  As  regards  major  fish  life,  there  are  undoubtedly  polluted  zones  where  the 
dissolved  oxygen  content  and  other  features  resulting  from  the  discharge  of  sewage 
are  such  as  to  make  unsuitable  the  waters  in  the  vicinity  for  supporting  fish  life.  It  is 
not  believed,  however,  that  this  is  generally  true  of  the  main  watercourses. 

11.  The  local  sewage  problem  consists  essentially  in  the  corrective  treatment  of 
nuisances  offensive  to  the  senses  of  sight  and  smell  and  in  the  consideration  of  meas- 
ures to  be  adopted  sooner  or  later  in  the  development  of  a  program  which  shall  result 
in  maintaining  a  reasonable  degree  of  cleanness  in  the  waters  receiving  the  sewage  of 
New  York  City. 

Proposed  Standards  op  Cleanness 

I  have  noted  the  proposed  degree  of  cleanness  which  the  Commission  recommends 
for  the  waters  in  the  vicinity  of  New  York  City,  as  follows: 

"1.  Garbage,  offal  or  solid  matter  recognizable  as  of  sewage  origin  shall  not 
be  visible  in  any  of  the  harbor  waters. 

"2.  Marked  discolorization  or  turbidity,  due  to  sewage  or  trade  wastes,  ef- 
fervescence, oily  sleek,  odor  or  deposits,  shall  not  occur  except  perhaps  in  the 
immediate  vicinity  of  sewer  outfalls,  and  then  only  to  such  an  extent  and  in  such 
places  as  may  be  permitted  by  the  authority  having  jurisdiction  over  the  sani- 
tary condition  of  the  harbor. 

"3.  The  discharge  of  sewage  shall  not  materially  contribute  to  the  forma- 
tion of  deposits  injurious  to  navigation. 

"4.  Except  in  the  immediate  vicinity  of  docks,  piers  and  sewer  outfalls,  the 
dissolved  oxygen  in  the  water  shall  not  fall  below  3  cubic  centimeters  per  liter 
of  water.  With  60  per  cent,  of  sea  water  and  40  per  cent,  of  land  water  and  at 
the  extreme  summer  temperature  of  80  degrees  Fahrenheit,  3  cubic  centime- 
ters of  oxygen  per  liter  corresponds  to  58  per  cent,  of  saturation.  Near  docks  and 


REPORT  OF  GEORGE  W.  FULLER 


197 


piers  there  should  always  be  sufficient  oxygen  in  the  water  to  prevent  nuisance 
from  odors. 

"5.  The  quality  of  the  water  at  points  suitable  for  bathing  and  oyster  cul- 
ture should  conform  substantially  as  to  bacterial  purity  to  a  drinking  water 
standard.   It  is  not  practicable  to  maintain  so  high  a  standard  in  any  part  of 
the  harbor  north  of  the  Narrows,  or  in  the  Arthur  Kill.   In  the  Lower  bay  and 
elsewhere  bathing  and  the  taking  of  shell-fish  cannot  be  considered  free  from 
danger  of  disease  within  a  mile  of  a  sewer  outfall." 
As  a  set  of  rules,  the  observance  of  which  should  be  the  aim  in  considering  the  dis- 
posal of  sewage  for  New  York  City,  I  do  not  believe  that  serious  exception  can  be  taken 
to  the  foregoing  standards,  reasonably  interpreted,  other  than  to  Rule  4  specifying  the 
minimum  residual  quantity  of  dissolved  oxygen  considered  permissible  in  the  waters  ex- 
cept at  docks,  piers  and  sewer  outfalls. 

In  my  judgment  this  minimum  quantity  of  3  cubic  centimeters  of  dissolved  oxy- 
gen per  liter,  equal  to  4.3  parts  per  million,  and  about  58  per  cent,  of  saturation  at 
summer  temperatures  for  the  harbor  water,  consisting  of  about  60  per  cent,  of  sea 
water,  is  a  needlessly  high  limit,  the  attainment  of  which  is  not  necessary  to  a  general 
program  of  securing  inoffensive  and  reasonably  clean  harbor  waters.  A  much  smaller 
quantity  will,  in  fact,  suffice. 

It  is  my  belief  that  the  significance  of  this  matter  has  not  been  well  understood 
by  many  of  those  considering  this  question;  and  indeed  has  been  confused  needlessly 
with  assumptions  as  to  requirements  for  major  fish  life  and  a  desire  to  provide  a  very 
liberal  margin  of  safety  in  guarding  against  offensive  odors. 

Deoxygenation  of  the  waters  overlying  putrefying  sludge  deposits  has  compli- 
cated quite  seriously  many  of  the  limited  data  now  available  upon  this  topic. 

In  again  taking  up  this  question  below,  I  shall  go  more  into  detail,  but  it  appears 
to  me  that  many  writers  upon  this  question  have  not  carefully  noted  the  absence  of 
putrefactive  odors  where  dissolved  oxygen  has  fallen  to  much  smaller  figures  than 
stated  in  the  above  proposed  standard. 

Metropolitan  Sewerage  Commission's  Program 

The  essence  of  the  program  which  the  Commission  has  developed  deals  particularly 
with  the  following  decisions : 

1.  Suspended  particles  of  sewage  origin  readily  visible  to  the  naked  eye  should  be 
removed  from  practically  all  of  the  sewage  before  it  is  discharged  into  any  of  the  ad- 
joining waters. 

2.  It  is  futile  to  attempt  to  make  the  water  in  New  York  harbor  and  adjacent  wa- 
tercourses of  a  hygienic  quality  suitable  in  a  raw  condition  for  bathing,  except  by  a 
thorough  and  expensive  sterilization.  Even  if  the  dry-weather  flow  of  all  sewers  were 
removed  from  the  harbor  waters  they  would  still  fall  far  below  clean-water  standards 
necessary  to  insure  safe  bathing  and  the  safe  raising  of  shell-fish.  This  is  owing,  of 
course,  to  the  overflow  discharges  at  times  of  storms  from  the  existing  sewers,  which  are 
built  to  carry  both  the  domestic  wastes  and  the  rain-water  falling  upon  the  streets, 
roofs  of  buildings,  areaways  and  unoccupied  land. 

3.  Dispersion  or  dilution  of  the  flow  from  existing  sewer  outlets  into  neighboring 
watercourses  results  in  many  cases  in  faulty  mixing  of  the  sewage  with  the  harbor  wa- 
ters. In  some  cases  this  inadequate  mixing  of  sewage  and  harbor  waters  can  be  cor- 
rected without  great  difficulty  by  releasing  the  sewage  from  pipes  laid  on  the  stream 


198 


REPORTS  OF  EXPERTS 


bed  so  that  there  will  be  a  prompt  mixing  of  the  sewage  with  sufficient  moving  water. 
In  other  instances  the  relative  proportion  of  sewage  to  clean  water  available  for  dilu- 
tion is  such  as  to  preclude  an  entirely  satisfactory  solution  of  the  problem  without 
removing  the  sewage  in  an  interceptor  to  a  point  somewhat  distant  from  the  present 
sewer  outfalls. 

4.  Deposits  of  sewage  sludge  on  the  bottom  of  the  harbor  and  certain  of  the  ad- 
joining watercourses,  particularly  in  the  vicinity  of  slips  near  large  sewer  outlets,  rob 
the  harbor  waters  of  much  of  their  atmospheric  oxygen  and  lessen  materially  the  quan- 
tity of  clarified  sewage  that  can  be  satisfactorily  disposed  of  by  dilution. 

5.  The  disposal  by  dilution  of  the  city  sewage  into  neighboring  waters  in  a  care- 
fully considered  manner  is  the  most  suitable  way  of  disposing  of  a  very  large  portion 
of  the  sewage  of  New  York  City. 

6.  The  proposition  of  collecting  all  of  the  sewage  of  New  York  City  and  discharg- 
ing it  through  tunnels  at  sea  off  the  southern  coast  of  Long  Island  has  been  decided  by 
the  Commission  to  be  inadvisable  on  the  ground  of  excessive  cost  as  compared  with 
other  procedures  which  would  give  satisfactory  results. 

7.  A  central  plant  for  the  application  of  the  sewage  of  New  York  City  to  land 
for  purposes  of  sewage  farming  is  also  barred  on  the  ground  of  excessive  cost. 

8.  Disposal  of  the  sewage  by  filtration  in  plants  of  the  intensive  type,  such  as 
sprinkling  filters,  is  likewise  considered  unjustifiable  on  the  ground  of  the  cost  which 
would  be  involved  by  works  so  built  and  so  located  as  to  be  inoffensive  to  the  neighbor- 
ing property  owners. 

9.  The  basic  feature  of  the  procedure  recommended  by  the  Commission  is  to  treat 
the  sewage  of  each  natural  drainage  district  in  accordance  with  the  individual  require- 
ments of  this  district.  This  allows  use  to  be  made  of  the  dilution  method  for  the  di- 
gesting and  disposing  of  the  clarified  sewage  up  to  the  full  limit  of  practicability,  if 
such  limit  should  be  needed,  in  any  or  all  of  the  subdivisions  which  you  have  made  of 
the  area  of  the  Metropolitan  Sewerage  District.  It  also  has  the  advantage  of  allowing 
the  construction  work  to  be  carried  on  piecemeal ;  work  may  be  begun  where  it  is  most 
needed,  and  necessary  improvements  need  not  then  be  delayed  until  funds  can  be  raised 
and  construction  work  accomplished  for  a  large  central  disposal  project. 

10.  It  is  the  conclusion  of  the  Commission  that  the  needed  improvements  in  dis- 
posing of  the  sewage  of  New  York  City  should  be  carried  out  under  the  control  of  some 
central  authority  which  would  see  that  progressive  construction  work  is  executed  in 
conformity  with  a  comprehensive  design  looking  well  to  the  future  needs  of  the  Metro- 
politan District  as  a  whole.  Such  a  central  authority  would  also  see  to  it  that  the  work 
is  directed  first  to  solving  problems  which  are  in  greatest  need  of  attention  and  in  gen- 
eral in  coordinating  the  construction  procedures  with  the  financial  aspects. 

General  Endorsement  of  Commission's  Program  as  Above  Stated 

Dealing  in  a  broad  way  with  the  recommendations  of  the  Commission  as  outlined 
in  the  foregoing  ten  paragraphs,  and  passing  by  for  the  present  the  question  of  the 
residual  quantity  of  dissolved  oxygen  and  the  consequent  amount  of  purification  to 
maintain  the  standard  adopted,  I  am  clearly  of  the  opinion  that  the  recommendations 
are  sound. 

I  take  it  that  the  citizens  and  taxpayers  of  New  York  City  are  ready  to  adopt  im- 
proved sewage  disposal  procedures  which  will  correct  objectionable  putrefactive  condi- 


REPORT  OF  GEORGE  W.  FULLER  199 

tions  and  in  general  to  proceed  on  a  program  whereby  visible  objects  of  sewage  origin 
will  be  removed  from  the  sewage  before  its  discharge  into  the  harbor  waters. 

I  am  equally  convinced  that  this  community  does  not  desire  and  will  oppose  the 
expending  of  such  large  sums  of  money  as  would  be  required  either  for  pumping  all  of 
the  sewage  of  New  York  to  a  point  of  disposal  in  the  deep  waters  of  the  ocean  or  for 
applying  it  to  many  square  miles  of  farm  land  upon  Long  Island,  or  for  filtering  and 
oxidizing  the  sewage  so  that  its  purity  would  be  comparable  with  that  of  the  waters 
of  the  Hudson  river  above  New  York  City. 

The  problem  is  essentially  that  of  constructing  works  for  clarifying  the  sewage 
by  means  of  screens  or  by  subsidence  in  settling  tanks,  or  by  both,  and  of  distributing 
the  partially  clarified  sewage  so  that  it  will  be  properly  mixed  with  an  adequate 
quantity  of  water.  With  this  done  I  am  satisfied  that  adequate  and  proper  results  will 
be  obtained,  although  I  am  aware  that  most  careful  attention  must  be  given  in  some 
instances  to  lessening  the  effect  of  sewage  deposits  that  are  at  present  seldom  or  never 
dredged  and  in  other  instances  to  diverting  the  sewage  for  a  greater  or  less  distance 
from  its  point  of  origin  to  a  suitable  place  for  its  treatment  and  the  mixing  of  the 
treated  sewage  with  sufficient  diluting  water. 

I  am  strongly  in  favor  of  the  erection  of  a  central  authority  which  shall  direct  in  a 
businesslike  way  the  progressive  improvements  that  are  needed  in  solving  the  sewage 
disposal  problems  of  New  York  City  so  as  to  harmonize  the  work  that  is  done  year 
by  year  in  accordance  with  a  comprehensive  and  systematic  plan.  This,  in  my  opinion, 
is  a  necessary  element  to  conform  with  the  needs  of  efficient  city  planning.  Haphaz- 
ard execution  of  disjointed  plans  is  bound  to  lead  to  unsatisfactory  results  as  well 
as  to  waste  of  the  public  funds.  It  is  necessary  that  the  administrative  body  control- 
ling the  sewage  disposal  policy  of  the  city  shall  consider  the  requirements  and  welfare 
of  the  city  as  a  whole. 

Reverting  now  to  the  terms  of  the  inquiry  which  you  have  made  of  me,  I  take  it 
that  what  you  have  asked  may  be  briefly  stated  as  follows : 

Is  our  knowledge  now  sufficiently  definite  on : 

A.  Present  shortcomings  of  the  method  of  disposing  of  the  sewage  of  New 

York  City;  and 

B.  Corrective  measures ; 

as  to  warrant  the  adoption  of  a  general  plan  for  disposing  of  the  sewage  of  Greater 
New  York ;  or  are  the  advances  in  the  future  likely  to  make  present  designs  injudicious 
either  from  the  standpoint  of  efficiency  or  of  cost? 

Without  any  hesitancy  I  can  answer  your  inquiry  by  saying  that  the  present  state 
of  the  art  of  sewage  disposal  is  such  that  it  is  feasible  to  proceed  with  plans  for  the 
progressive  improvement  of  methods  of  sewage  disposal  which  will  lead  at  reasonable 
cost  to  the  dispersion  of  suitably  clarified  sewage  in  adequate  volumes  of  relatively 
clean  harbor  water. 

Future  developments  in  the  art  of  clarifying  sewage  will  no  doubt  result  in 
securing  higher  efficiency  for  a  given  investment,  other  things  being  equal,  than  can 
be  now  obtained.  However,  it  is  my  belief  that  designs  made  now  for  devices  for 
settling  sewage  and  disposing  of  the  resulting  sludge  will  not  for  many  years  become 
obsolete. 

I  am  convinced  that  the  time  and  conditions  will  never  arrive  when  any  great  part 
of  the  sewage  of  New  York  City  will  either  be  sent  to  sea,  applied  to  land  or  to  filters 
of  any  type. 


200 


REPORTS  OF  EXPERTS 


My  task,  therefore,  resolves  itself  into  a  recital,  in  the  first  place,  of  why  a  central 
plant  for  deep-sea  disposal,  land  treatment,  or  filtration,  will  not  be  needed  for  the 
whole  city,  and  secondly,  of  my  views  as  to  certain  features  of  the  progressive  im- 
provement of  the  present  sewage  disposal  methods  of  each  of  the  natural  drainage  areas 
of  New  York  City. 

Undesirability  op  Deep-Sea  Disposal  at  a  Central  Point 

In  its  Preliminary  Report  I,  dated  September,  1911,  the  Commission  outlines  a 
proposition  which  it  considers  practicable  but  not  necessary  for  delivering  the  sew- 
age of  Greater  New  York  to  large  storage  reservoirs  in  the  neighborhood  of  Barren 
Island ;  whence  the  sewage  would  be  discharged  on  the  outgoing  tide  through  tunnels, 
4  in  number,  18  feet  in  diameter,  and  leading  to  a  point  some  3  miles  north  of  the 
Ambrose  channel  light  vessel  and  about  5  miles  southeast  of  Rockaway  point.  The 
investment  cost  is  stated  to  be  estimated  as  "not  less  than  $140,600,000."  In  this  sum 
no  reference  is  made  to  the  annual  cost  of  operation  and  maintenance,  which  would  be 
a  very  substantial  item,  owing  to  the  necessity  of  pumping. 

Such  a  method  of  disposal  of  the  sewage  of  New  York  City  would  have  a  prece- 
dent in  the  practice  at  Boston.  There,  however,  the  amount  of  clean  water  available 
for  the  dilution  of  sewage  along  portions  of  the  water  front  of  the  inner  harbor  was 
merely  nominal  as  compared  with  that  which  is  available  in  most  of  the  open  water- 
courses in  and  around  New  York  City. 

I  consider  that  it  would  be  possible  to  apply  this  method,  if  it  were  needed,  to  ob- 
tain satisfactory  results  in  New  York.  I  have  noted  the  reference  of  the  Commission 
to  the  probable  offensiveness  of  the  sewage  which  would  have  passed  through  such  a 
long  length  of  tunnels  as  to  bring  about  a  state  of  decomposition  that  would  make  it  far 
more  offensive  than  fresh  sewage.  While  this  point  is  well  taken,  I  consider  that  by 
means  of  aeration  and  the  use  of  sterilizing  agents  properly  applied,  the  decomposition 
of  the  sewage  while  in  transit  could  probably  be  so  arrested  as  to  prevent  serious  of- 
fense resulting  at  the  outfall,  though  not  without  incurring  a  material  expense  in  so 
doing. 

But  the  principal  point  here  to  be  noted  is  that  there  is  no  need  whatever  of  going 
to  the  expense  of  adopting  deep-sea  disposal  for  all  of  the  sewage  of  New  York,  with 
its  burden  for  interest,  sinking  fund  and  operating  expenses,  based  on  your  estimates, 
amounting  to  not  less  than  about  $1.50  per  annum  per  capita.  Suitable  disposal  for 
the  New  York  problem  can,  as  the  Commission  states,  be  secured  for  far  less  expense 
than  this. 

It  is  also  to  be  pointed  out  to  the  idealist  who  wants  no  vestige  of  impurity  in  the 
waters  of  New  York  harbor,  that  even  the  diversion  of  the  entire  dry-weather  flow  of 
the  sewers  of  New  York  and  a  substantial  portion  of  the  storm  flows  thereof  would  not 
result  at  all  times  in  a  perfectly  clear  harbor  water.  This  would  be  owing  partly  to 
the  storm  flows  from  the  sewers,  which  at  times  would  be  far  in  excess  of  capacity  of 
any  tunnels  which  the  city  would  be  able  to  build ;  partly  to  the  soil  wash  and  swampy 
discoloration  brought  to  the  harbor  by  the  Hudson  river  at  times  of  flood;  and  partly 
perhaps  to  the  sewage  of  cities  whose  disposal  methods  would  be  entirely  beyond  the 
control  of  the  City  of  New  York. 

While  the  clear  water  from  the  sea  would  be  an  attractive  factor  at  certain  times 
in  the  watercourses  around  New  York,  it  is  entirely  impossible  to  secure  it  at  all  times. 
Judging  by  experiences  of  those  who  live  on  the  muddy  watercourses  of  our  southern 


REPORT  OF  GEORGE  W.  FULLER 


201 


and  western  rivers,  the  ordinary  feeling  is  that  it  is  not  worthy  of  serious  consideration 
to  figure  on  doing  anything  more  than  to  free  the  New  York  harbor  waters  of  readily 
visible  signs  of  their  pollution  by  sewage  wastes. 

In  my  judgment  it  is  needless  to  discharge  all  the  sewage  of  New  York  City  into 
the  ocean  at  a  central  point  and  it  is  perfectly  safe  for  the  officials  of  this  city  to  drop 
the  question  for  all  time. 

Undesibability  of  Applying  the  Sewage  of  New  Yobk  City  to  Sewage  Fabms  on 

Long  Island 

Since  the  earliest  days  of  the  water-carriage  method  of  removing  domestic  wastes 
through  underground  channels  there  has  been  in  nearly  all  large  communities  much 
discussion  at  intervals  of  the  deplorable  waste  of  the  manurial  value  of  the  contents  of 
city  sewers.  To  those  who  do  not  take  the  trouble  to  look  carefully  into  the  matter  this 
question  will  no  doubt  continue  to  be  a  vexation. 

Our  sewage  contains  about  one  part  of  total  organic  matter  in  5,000  parts  of 
water.  If  the  organic  matter  could  be  treated  and  made  available  as  a  fertilizer,  with- 
out having  to  go  to  the  expense  of  dealing  with  the  water  used  for  transporting  the  sew- 
age through  the  sewers  in  the  city  streets  from  the  point  of  origin  to  the  point  of  dis- 
posal, this  question  would  assume  entirely  different  proportions. 

The  late  Dr.  Thomas  M.  Drown,  formerly  Chemist  of  the  Massachusetts  State 
Board  of  Health,  and  later  President  of  Lehigh  University,  in  discussing  this  question 
employed  a  very  apt  illustration.  He  said  that  several  million  dollars  worth  of  gold 
exist  in  the  soil  upon  which  the  city  of  Philadelphia  is  located.  It  is  impracticable  as 
a  business  proposition,  and  for  all  time  to  come  will  continue  to  be  so,  to  extract  this 
gold.  So  it  is  with  the  question  of  extracting  the  manurial  constituents  of  sewage 
from  the  relatively  enormous  volumes  of  water  with  which  they  are  mixed. 

In  its  Preliminary  Report  I,  dated  September,  1911,  the  Commission  states  that  an 
area  of  about  175  square  miles  of  land  would  be  needed  if  disposal  by  sewage  farming 
or  broad  irrigation  were  adopted,  on  the  basis  of  12,000  gallons  of  sewage  per  acre  per 
24  hours,  and  that  the  tract  of  land  nearest  to  New  York  of  suitable  elevation  and 
proper  quality  of  soil  which  can  be  found  is  in  the  stretch  from  Amityville  to  Quogue, 
a  distance  of  some  50  miles  from  the  city.  The  report  further  states  that  such  a  project 
would  cost  more  than  §153,000,000,  of  which  about  §140,000,000  would  be  for  the  col- 
lection and  delivery  of  the  city  sewage  to  the  sewage  farms.  While  these  estimates 
provide  for  a  capacity  sufficient  to  take  care  of  the  dry-weather  sewage  flow  from  a 
population  of  about  9  million  people,  estimated  to  be  reached  by  New  York  City  in 
1940,  they  do  not  provide  for  any  reserve  area,  which,  in  my  opinion,  would  be  needed 
for  receiving  the  sewage  at  times  of  prolonged  rainfall,  or  for  the  purchase  of  a  strip 
of  land  around  the  sewage  farms  so  as  to  guard  against  complications,  due  to  odors, 
from  neighboring  property  owners. 

I  have  had  occasion  to  look  into  the  question  of  the  use  of  sewage  farms  at  various 
places  both  in  the  arid  districts  of  America  and  elsewhere  in  this  country,  as  well  as 
in  Europe.  Where  there  is  ordinarily  an  abundance  of  rainfall  sewage  farming  on  a 
large  scale  has  not  proven  a  sanitary  success,  owing  to  the  difficulty  during  periods  of 
heavy  rainfall  and  while  harvesting  the  crops  of  preventing  the  sewage  from  flowing  to 
the  nearest  watercourse  in  an  untreated  condition.  Complications  have  arisen  not 
only  with  riparian  owners  along  watercourses  below  sewage  farms,  but  difficulties  have 
also  been  encountered  from  odors  arising  from  the  decomposition  of  "pooled"  sewage 


202 


REPORTS  OF  EXPERTS 


that  accumulates  at  certain  seasons  on  clogged  land  that  becomes  "sewage  sick,"  even 
in  instances  where  the  soil  was  originally  fairly  porous. 

Sewage  farming  is  prompted  by  one  or  both  of  two  objects.  One  of  these  is  to 
utilize  the  fertilizing  value  of  the  sewage  and  the  other  is  to  take  advantage  of  the  irri- 
gating properties  of  the  water  content  of  the  sewage. 

Experience  abundantly  demonstrates  that  with  the  dilute  sewage  of  America  the 
cost  under  all  ordinary  circumstances  of  delivering  sewage  to  suitable  sites  for  sewage 
farming  far  exceeds  the  value  to  be  derived  from  the  sewage  from  its  combined  fer- 
tilizing and  irrigating  properties. 

I  looked  into  this  question  with  some  care  a  few  years  ago  at  El  Paso,  Texas,  and 
found  that  it  would  cost  more  to  deliver  the  sewage  to  suitable  areas  for  a  city  sewage 
farm  than  would  be  the  total  cost  of  subjecting  the  sewage  to  purification  in  modern 
intensive  treatment  works  located  fairly  close  to  the  city.  The  absence  of  well-devel- 
oped practicable  working  sewage  farms  in  the  vicinity  of  any  sizable  American  city, 
even  in  the  arid  regions,  indicates  that  sewage  farming  carries  a  financial  burden  far 
beyond  any  possible  benefits  to  be  derived  from  the  sewage  itself.  Citations  need  to  be 
made  only  to  the  abandonment  some  ten  years  ago  of  the  sewage  farms  at  Los  Angeles, 
Cal.,  in  favor  of  disposal  through  an  outfall  sewer  to  the  Pacific  ocean,  to  a  similar 
fate  in  the  near  future  for  the  Pasadena  sewage  farms  and  to  the  absence  during  a 
period  of  more  than  20  years  of  any  successful  utilization  for  irrigating  purposes  of  the 
flow  of  the  main  outfall  sewer  of  Denver,  Col. 

Reference  is  frequently  made  to  the  sewage  farming  experiences  of  sizable  cities  of 
Europe,  particularly  Paris  and  Berlin.  At  the  latter  city  conditions  were  unusually 
favorable  as  to  character  of  soil,  price  of  land  secured  many  years  ago  and  the  low 
mean  rainfall  of  some  25  inches,  making  the  irrigating  properties  of  the  sewage  of  sub- 
stantial worth.  Even  under  European  conditions  it  is  significant  to  note  the  substan- 
tial abandonment  of  the  largest  sewage  farm  in  England,  namely,  at  Birmingham ;  the 
adoption  of  sprinkling  filters  for  large  suburban  areas  around  Paris  and  Berlin  as 
noted  by  the  large  installations  at  Mount  Mesley  and  Wilmersdorf,  respectively. 
Furthermore,  the  city  of  Paris  itself,  instead  of  increasing  its  sewage  farms,  is  adopt- 
ing sprinkling  filters,  the  first  installation  having  been  completed  about  a  year  ago. 

Even  at  Berlin,  where  conditions  are  probably  the  most  favorable  of  any  place,  the 
total  gross  income  exceeds  but  slightly  the  outgo  for  operation  and  maintenance,  leav- 
ing but  a  nominal  sum  available  for  interest  charges. 

A  large  sewage  farm  on  Long  Island  could  advantageously  receive  city  sewage  for 
a  much  smaller  number  of  days  in  the  year  than  is  the  case  at  Berlin.  This  means 
either  that  the  sewage  would  be  applied  to  the  land  in  quantities  and  at  times  that 
would  be  prejudicial  to  the  raising  of  crops,  with  the  attending  likelihood  that  over 
portions  of  the  area  it  would  accumulate,  putrefy  and  give  off  offensive  odors ;  or  that 
it  would  be  diverted  to  neighboring  watercourses  for  days  at  a  time ;  or  that  it  would 
be  necessary  to  provide  immense  storage  reservoirs  in  which  to  retain  the  sewage  for 
weeks  and  probably  months  at  a  time,  as  is  the  case  at  Berlin  and  at  San  Antonio, 
Tex.,  so  as  to  use  it  only  when  the  application  would  be  either  advantageous  or  permis- 
sible in  the  interests  of  crop  raising. 

Taking  into  account  the  enormous  expense  involved,  the  unreliability  of  sewage 
farming  compared  with  numerous  other  available  methods  of  sewage  treatment,  I  am 
convinced  that  there  is  absolutely  no  opportunity  for  sewage  farming  to  become  worthy 
of  practical  significance  in  solving  the  sewage  problem  for  New  York. 


KEPORT  OF  GEORGE  W.  FULLER 


203 


Impracticability  op  a  Central  Plant  to  Treat  All  the  Sewage  of  New  York  City 

by  Intensive  Purification  Methods 

If  New  York  were  an  inland  city  situated  on  a  comparatively  small  stream  so  as  to 
necessitate  the  use  of  treatment  works  to  oxidize  the  soluble  and  non-settling  organic 
constituents  of  its  sewage,  the  present  state  of  the  art  of  sewage  disposal  clearly  indi- 
cates that  the  most  practicable  method  would  be  to  apply  settled  sewage  to  sprinkling 
filters  so  as  to  oxidize  the  sewage  sufficiently  to  make  it  non-putrescible. 

This  is  the  method  adopted  at  Birmingham,  England;  for  the  suburban  areas 
around  Paris  and  Berlin;  at  Baltimore,  Md.,  Atlanta,  Ga.,  Columbus,  Ohio,  and  prac- 
tically every  sizable  city  in  America  that  has  had  occasion  recently  to  figure  seriously 
upon  disposing  of  its  organic  wastes  where  the  dilution  method  of  dispersion  in  a  rela- 
tively large  watercourse  was  not  available. 

In  its  Preliminary  Report  I,  dated  September,  1911,  the  Commission  summarizes 
its  studies  indicating  that  it  would  cost  approximately  $141,000,000  for  treatment 
works  of  the  type  above  mentioned  located  on  Barren  Island  of  a  size  to  take  only 
the  dry-weather  flow  of  a  population  of  9  millions  of  people,  estimated  to  reside  in  New 
York  City  in  1940,  and  does  not  recommend  this  solution  of  the  problem. 

It  may  be  that  in  the  future  some  method  may  be  developed  through  the  use  of  oxi- 
dizing chemicals  combined  with  aeration  so  as  to  be  able  to  secure  an  equal  effect  at 
less  expense  than  by  the  use  of  sprinkling  filters.  In  my  opinion  it  is  useless  to  attempt 
to  discuss  such  possibility  of  the  future  art  of  sewage  disposal  as  applied  to  local  prob- 
lems, partly  on  account  of  lack  of  information  to  suggest  the  nature  of  future  develop- 
ments, but  principally  on  account  of  the  undesirability  of  adopting  any  method  of 
central  disposal  for  the  sewage  of  New  York  City.  In  a  word,  I  agree  fully  with  the 
conclusions  of  the  Commission  that  sprinkling  filters  at  a  central  point  for  treating  all 
of  the  sewage  of  New  York  City  would  involve  an  expense  that  is  unjustifiable. 

As  the  years  go  by  it  is  quite  possible  that  in  some  districts  special  methods  of 
oxidizing  the  sewage  may  be  necessary  in  adequately  taking  care  of  the  sewage  of  an 
increased  population,  but  a  central  plant,  in  my  judgment,  is  entirely  out  of  the  ques- 
tion during  the  next  generation,  and  probably  for  all  time. 

Sprinkling  filters,  while  the  cheapest  method  of  securing  a  sewage  effluent  which 
will  not  putrefy,  are  liable  to  involve  nuisances  from  the  standpoint  of  odors.  If  the 
sewage  could  be  kept  in  a  fresh  condition,  as  is  the  case  at  the  five-year-old  plant  at 
Reading,  Pa.,  odors  would  rarely  if  ever  be  noticed  as  much  as  100  yards  distant.  On 
the  other  hand,  at  Columbus,  Ohio,  and  Baltimore,  Md.,  a  zone  surrounding  the  plant 
one-fourth  mile  in  extent  has  been  found  at  times  to  be  insufficient  to  prevent  odors 
from  reaching  residents  living  beyond  that  limit,  owing  to  the  advanced  stage  of  de- 
composition to  which  the  sewage  has  progressed  before  it  reaches  the  sprinkling  fil- 
ters. Contact  beds,  per  cubic  yard  of  filtering  material,  operate  at  rates  about  one- 
third  as  high  as  do  sprinkling  filters,  but  the  likelihood  of  odors  is  much  less.  This  is 
because  with  contact  beds  the  sewage  is  not  thrown  into  the  air  from  nozzles  in  the 
form  of  spray,  but  is  applied  at  the  bottom  of  the  filter  beds  and  not  allowed  to  come 
to  view  at  the  surface. 

Mention  is  made  of  these  latter  features  having  in  mind  that  while  a  central  filter 
plant  will  not  be  needed  for  the  New  York  sewage,  it  may  be  found  proper  in  certain 
areas  to  supplement  the  work  of  fine  screens  or  settling  basins  previous  to  dispersion  of 
the  sewage  in  the  neighboring  watercourses. 


204 


REPORTS  OF  EXPERTS 


Synopsis  op  Program  Adopted  by  the  Commission 

Having  considered  and  concurred  in  the  conclusions  of  the  Commission  as  to  the 
great  cost  and  lack  of  necessity  of  disposing  of  the  sewage  of  New  York  City  at  any 
central  plant  regardless  of  type,  I  shall  now  proceed  to  state  my  views  on  the  program 
laid  down  by  the  Commission  for  disposing  of  the  sewage  of  the  several  natural  drain- 
age divisions  of  Greater  New  York  into  which  you  have  divided  the  area  and  for  which 
you  have  proposed  treatment  methods  depending  upon  various  local  conditions  and 
factors. 

It  is  needless  to  repeat  from  your  reports  in  great  detail  a  description  of  these 
methods  of  treatment  and  the  areas  to  which  it  is  proposed  to  apply  each  method.  But 
for  the  sake  of  explicitness  I  shall  briefly  sum  up  in  tabular  form  some  of  the  principal 
data,  as  they  are  set  forth  in  your  reports. 

The  area,  population,  number  of  sewer  outlets  and  the  watercourses  into  which 
these  outlets  discharge  are  all  of  much  interest  to  the  reader  of  these  reports,  and  I 
have  endeavored  to  summarize  your  findings  in  this  regard  in  Table  XX. 


TABLE  XX 

City  Divisions  and  Discharge  Points  for  Sewage 


Division. 

Subdivision. 

Area 

in 
Acres. 

1910 

Populatio 

1940 
(Esti- 
mated). 

n. 

Per  Acre. 

Proposed 
Sewer  Outlets. 

1910 

1940 

(Est.) 

Num- 
ber. 

Discharge  to 

Jamaica  bay. . 

19,900 
30,900 

270,000 
81,000 

619,000 
290,000 

14 
3 

32 
9 

1 
1 

Outlet  island. 
Jamaica  bay. 

Upper  East 
river  and 
Harlem  

Northwestern  Queens  

12,100 
10,600 

3,100 
16,800 

5,900 

995,300 
30,300 
10,000 
62,200 
8,000 

2,105,800 
73,600 
28,500 
179,800 
22,900 

81 
3 
3 
4 

1  + 

173 
7 
9 
11 
4 

1 
1 
1 
1 
1 

Hellgate  at  Wards  Isl. 

(at  Hunts  Point). 
Hell  Gate  at  Wards  Isl. 

and  East  River. 
Hell  Gate  opposite  Wards 

Island. 
East   river   at  College 

Point. 

East     river  opposite 
Throg's  Neck. 

Richmond .... 

Quarantine  

Livingston  

West  New  Brighton  

Elm  Park  

817 
1,714 

959 
5,056 
632 

7,461 
19,393 
11,433 
17,491 

8,542 

68,470 
132,255 

88,575 
286,220 

58,100 

9 
11 
12 

3 
13 

84 
77 
92 
51 
92 

1 
1 
1 
1 
1 

Narrows. 
« 

Kill  van  Kull. 

a 

u 

Lower  Hudson, 
Lower  East 
river  and 
bay  

Hudson  

Manhattan,  Lower  E.  side. 

Brooklyn,  northwestern  

Western  Jamaica  bay  

5,600 
1,737 
5,790 
19,000 

726,000 
680,500* 
732,313* 
343,000* 

1,470,000 

130 
393* 
127* 
18* 

263 

Hudson  river. 
Outlet  island. 

*  =  1915. 


A  marked  variation  is  found  in  the  volume  of  water  available  for  the  absorption 
and  digestion  of  sewage  reaching  the  various  sections  of  New  York  harbor.  As  a 
matter  of  convenience  for  reference  I  have  copied  in  Table  XXI  the  data  given  on  page 
26  of  the  Preliminary  Report  VI  of  the  Commission,  dated  February,  1913 ;  and  to  this 
I  have  added  a  memorandum  indicating  roughly  whether  or  not  sewage  deposits  now 
pollute  the  main  channel  or  shores  of  the  respective  watercourses  or  subdivisions  of  the 
harbor: 


REPORT  OF  GEORGE  W.  FULLER  205 

TABLE  XXI 
Volume  of  Water  in  Millions  op  Cubic  Feet 


Division  of  the  Harbor. 


Harlem  river  

Hudson  river.  Battery  to  Mt.  St.  Vincent 

Upper  East  river  

Lower  East  "   

Upper  bay  

Newark  bay  

Kill  van  Kull  

Jamaica  bay  


American  engineers  for  many  years  have  been  accustomed  in  their  deliberations 
on  problems  for  the  disposal  of  sewage  by  dilution  to  note  the  available  quantities  of 
water  expressed  in  terms  of  cubic  feet  per  second  per  thousand  population  connected 
with  the  sewers. 

Without  attempting  to  enter  into  the  question  of  the  accuracy  either  of  available 
quantities  of  water  or  of  estimates  of  future  population,  I  give  in  Table  XXII  certain 
dilution  factors  deduced  from  the  data  of  Tables  XXI  and  XX. 

These  computations  show  at  once  that  the  principal  problems  of  sewage  disposal 
relate  to  the  Harlem  river,  the  Lower  East  river  and  Jamaica  bay,  and  not  to  any  sub- 
stantial extent,  for  the  next  generation,  to  the  Hudson  river,  Upper  bay  or  Kill 
van  Kull. 

TABLE  XXII 


Dilution  Factors  in  Cubic  Feet  per  Second  per  1,000  Population 


Section. 

1910 

1940 

Tidal  Prism. 

Net  Ebb  Flow. 

Tidal  Prism. 

Net  Ebb  Flow. 

4.15 

0.42 

1.94 

.20 

Hudson  "   

37.9 

24.3 

19.6 

12.6 

230.0 

64.6 

6.19 

1.09 

3.85 

.70 

110.0 

55.6 

62.8 

31.6 

232.0 

22.8 

120.0 

11.8 

Kill  van  Kull  

67.0 

39.5 

24.1 

14.2 

126.00 

50.0 

These  figures  of  both  tidal  prism  and  net  ebb  flow  dilutions  are  not  of  themselves  a 
measure  of  the  condition  of  the  water  or  the  quantity  of  sewage  which  can  be  digested. 
The  net  ebb  flow  is  by  no  means  all  clean  water.  * 

The  effect  of  the  tidal  prism  is  to  make  the  sewage  received  by  the  waters  oscillate 
back  and  forth,  the  water  containing  the  sewage  becoming  more  polluted  until  it  has 
reached  the  point  where  the  outflow  of  sewage  with  the  tidal  water  balances  the  sewage 
supply.  Also  the  water  reaching  the  lower  sections,  such  as  the  bay,  from  water  such 
as  the  Hudson  river,  is  already  polluted.  On  the  other  hand,  reaeration  of  the  harbor 
water  is  a  helpful  factor,  affording  a  supply  of  oxygen  to  replace  in  part  that  absorbed 
through  the  digestion  of  sewage  matters. 


Below 
Mean 

Tidal 

Net  Ebb 
Flow  in 

Condition  of 
Bottom. 

Low 

Prism. 

12  Lunar 

Tide. 

Hours. 

Channel. 

Shores. 

285 

148 

15 

Polluted. 

Polluted. 

12,330 

1,697 

1,087 

Clean. 

a 

5,512 

1,869 

u 

u 

4,174 

552 

ioo 

a 

u 

12,970 

2,541 

1,283 

Polluted. 

Polluted. 

1,542 

1,071 

105 

u 

■ 

728 

150 

88 

u 

tt 

2,029 

1,977 

Clean. 

Clean. 

206 


REPORTS  OF  EXPERTS 


While  dilution  factors  thus  complicated  by  variability  of  quantity  and  quality  of 
diluting  water  and  by  the  uncertainty  of  the  beneficial  effects  of  reaeration  are  only  a 
rough  guide,  these  figures  of  this  Table  XXII,  taken  together  with  our  knowledge  of  the 
pollution  as  given  by  the  oxygen  content  in  Table  XIX,  throw  some  light  on  the  neces- 
sary purification  for  present  and  future  increased  sewage  flow. 

Efficiency  of  Methods  of  Sewage  Treatment 

As  to  the  efficiency  of  various  types  of  sewage  treatment  works,  I  have  noticed  the 
percentages  of  removal  which  it  is  assumed  may  be  obtained  as  given  on  page  30  of  your 
Preliminary  Report  VI,  dated  February,  1913.  I  believe  these  percentages  of  removal, 
as  you  have  estimated  them,  are  reasonable  deductions  from  present  data  and  can  be 
obtained  in  practice  in  plants  of  reasonable  cost.  In  fact,  I  note  that  the  percentages 
which  you  have  assumed  for  the  various  devices  do  not  differ  materially  from  the  esti- 
mates I  made  in  conjunction  with  Mr.  Rudolph  Hering  in  1906  in  a  report  on  the  Chi- 
cago Sanitary  District  for  the  International  Waterways  Commission,  and  which  fig- 
ures I  reproduced  in  my  book  on  "Sewage  Disposal,"  1912,  page  741. 

In  Table  XXIII  there  are  recorded  comparative  percentages  of  removal  of  sus- 
pended matter  and  organic  matter,  respectively,  to  be  expected  of  the  different  treat- 
ment methods,  as  given  by  your  Commission  and  myself : 


TABLE  XXIII 


Treatment  Method. 

Suspended  Matter. 

Organic  Matter. 

Met.  Com. 

G.  W.  F. 

Met.  Com. 

G.  W.  F. 

15 

15 

15 

10 

60 

65 

30 

30 

85 

85 

50 

50 

Sprinkling  filters  

90 

85-90 

70 

65-70 

The  Significance  of  the  Digestion  of  Sewage  Sludge  and  the  Absorption  of  Dis- 
solved Atmospheric  Oxygen  in  Sludge  Decomposition 

In  regard  to  percentages  of  removal  of  organic  matter,  the  significance  in  a  prac- 
tical way  of  the  withdrawal  of  atmospheric  oxygen  from  the  overlying  water  as  de- 
posits of  sludge  putrefy  upon  the  bottom  of  watercourses  has  pressed  itself  forward  for 
attention  since  most  of  the  data  were  obtained  for  arriving  at  the  conclusions  em- 
bodied in  Table  XXIII.  For  instance,  the  removal  of  organic  matter  by  sedimentation, 
given  as  30  per  cent.,  is  probably  a  little  high  judged  by  the  "atmospheric  oxygen  con- 
sumed" in  tests  of  short  duration  when  comparing  the  corresponding  data  obtained 
from  settled  and  unsettled  sewage. 

Notwithstanding  the  data  obtained  by  Dr.  Lederer,  of  Chicago,  and  Mr.  Hoover, 
of  Columbus,  on  atmospheric  oxygen  consumed,  as  given  in  my  book  on  "Sewage  Dis- 
posal," 1912,  page  421,  I  am  inclined  to  think  that  substantially  different  results  might 
have  been  obtained  if  the  tests  were  continued  for  a  longer  period  in  the  instance  of  the 
unsettled  sewage;  so  that  account  might  be  taken  of  the  deoxygenating  effect  of  sus- 
pended particles  which  slowly  respond  to  the  effect  of  septicization  and  produce  decom- 
position products  of  an  unstable  kind.  Without  doubt  the  larger  particles  of  suspended 
organic  matter  contain  relatively  less  putrescible  matter  that  readily  undergoes  bac- 


REPORT  OF  GEORGE  W.  FULLER  207 

terial  decomposition  than  is  the  case  either  with  soluble  or  very  finely  divided  sus- 
pended solids.  But  in  practical  sewage  disposal  problems,  where  the  dilution  method 
requires  improvement,  it  is  ordinarily  found  that  there  are  some  places  within  a  stream 
where  sludge  deposits  accumulate  and  gradually  undergo  decomposition  with  attending 
consumption  of  oxygen  from  the  overlying  waters.  In  particular  must  it  be  borne  in 
mind  that  sludge  deposits  during  the  winter  may  remain  relatively  dormant  and  be- 
come active  with  the  arrival  of  warm  weather  for  the  consumption  of  oxygen  from  the 
overlying  water  at  times  when  there  is  least  oxygen  available. 

Thus  the  sludge  deposited  uniformly  day  by  day  on  the  river  bottom  will,  during 
the  cold  weather,  inactively  accumulate;  and  with  the  advent  of  higher  temperatures 
in  summer  the  aggregate  volume  of  sludge  piled  up  will  act  in  an  intensified  manner. 

I  have  no  definite  data  at  hand  to  indicate  the  effect  of  temperature  upon  the  diges- 
tion of  sewage  sludge  accumulated  upon  stream  beds,  but  some  insight  may  be  obtained 
from  the  relative  quantities  of  gas  liberated  from  the  sludge  accumulations  in  a  small 
septic  tank  studied  at  Worcester,  Mass.,  some  years  ago,  as  follows : 


TABLE  XXIV 

Percentage  Which  the  Volume  of  Gas  Produced  Each  Month  in  Septic  Tanks  is 

of  the  Annual 

January   30  July    140 

February   62  August   167 

March    48  September   170 

April    51  October    116 

May   100  November    115 

June   148  December   65 

In  this  connection  reference  is  further  made  to  my  book,  pages  65-71  and  pages 
479-82,  dealing  especially  with  the  comparative  slowness  with  which  solid  organic  mat- 
ters decompose  as  compared  with  dissolved  organic  matter,  and  it  is  suggested  from  the 
Lawrence  data  that  gasification  does  not  occur  in  sewage  free  of  sludge. 

I  have  also  noted  in  this  connection  the  statements  of  Messrs.  McGowan,  Frye  and 
Kershaw  as  given  in  Vol.  II,  Appendix  to  the  Eighth  Report  of  the  Royal  Commission 
on  Sewage  Disposal  of  Great  Britain,  page  130.  After  studying  the  rate  at  which 
atmospheric  oxygen  during  the  period  of  five  days  was  absorbed  by  original  and  paper- 
filtered  samples  of  sewage  from  22  different  places,  the  conclusion  is  drawn  that — 

"We  think  it  may  be  taken  that  sewage  liquors  and  effluents  generally,  with 
their  suspended  solids,  will  take  up  about  twice  as  much  dissolved  oxygen,  in 
periods  up  to  five  days,  as  the  liquid  portion  alone  will  do." 
It  is  not  necessarily  to  be  deduced  that  the  final  or  absolute  oxygen  consumption, 
however,  will  be  in  the  same  proportion. 

In  the  absence  of  detailed  data  on  this  question  only  a  tentative  opinion  can  be 
formed.  But  there  is  enough  information  at  hand  to  indicate  the  need  of  much  more 
study  of  these  features  than  has  been  given  hitherto.  And  in  the  meantime,  I  attach 
much  weight  to  the  possibility  that  the  deoxygenating  effect  of  sludge  is  materially 
greater  than  its  proportionate  amount  of  organic  matter,  and  that  the  removal  of 
sludge  by  sedimentation  will  effect  an  improvement  more  than  proportionate  to  the 
weight  of  organic  matter  removed. 

Further  consideration  on  the  same  line  leads  me  to  the  thought  that  the  removal 


208 


REPORTS  OP  EXPERTS 


of  sludge  deposits  by  dredging  may  be  of  value.  I  understand  that  a  study  of  methods 
and  costs  of  such  sludge  removal  has  been  made  by  the  Commission. 

Probable  Future  of  Various  Sewage  Treatment  Methods 

You  have  asked  my  opinion  on  the  probable  future  changes  in  sewage  disposal  pro- 
cedures. I  shall  discuss  the  various  topics  briefly  in  the  light  in  which  I  now  regard 
their  probable  future  standing: 

Oxidation  Methods 

These  procedures  are  aimed  essentially  at  the  prevention  of  putrefaction  of  sew- 
age matters  and  hence  deal  particularly  with  soluble  and  colloidal  constituents  of 
sewage. 

Dilution.  This  is  the  prevailing  method  all  over  the  world  for  securing  the  oxida- 
tion of  soluble  or  non-settling  sewage  matters  wherever  there  is  ample  water  to  bring 
about  satisfactory  results.  Without  attempting  to  state  precisely  the  digestive  capacity 
of  New  York  harbor,  it  is  sufficient  to  say  that  for  all  time  to  come  it  will  oxidize  under 
suitable  conditions  the  clarified  sewage  of  many  millions  of  people.  Departures  from 
this  method  will  be  required  solely  in  areas  where  the  sewage  cannot  readily  be  deliv- 
ered to  bodies  of  water  of  sufficient  volume. 

The  dilution  method  has  usually  been  applied  in  this  country  under  improper 
conditions.  Clean  watercourses  can  be  maintained  with  the  dilution  method  and  past 
shortcomings  should  not  militate  against  the  advantages  and  economies  of  utilizing 
the  digestive  capacity  of  the  harbor  waters. 

Filtration.  Where  sewage  cannot  be  applied  to  diluting  bodies  of  water  on  account 
of  the  distance  from  same  and  the  expense  of  delivering  the  sewage,  filters  will  un- 
doubtedly continue  to  serve  a  useful  purpose.  I  believe  the  future  will  show  no  radical 
departures  in  the  efficiency  or  cost  of  either  sprinkling  or  contact  filters.  The  ten- 
dency will  be  towards  improvements  in  the  design  of  certain  details.  I  am  clearly  of 
the  opinion  that  filtration  has  no  future  so  far  as  relates  to  the  main  volume  of  New 
York  sewage. 

For  certain  areas,  particularly  those  now  comparatively  sparsely  populated,  I  think 
that  a  number  of  filter  plants  installed  and  operated  for  a  period  of  10  to  20  years 
may  in  the  end  prove  cheaper,  even  if  then  abandoned,  than  Avould  be  the  case  if  at 
the  outset  the  general  plan  should  embody  the  execution  of  collection  works  for  a  cen- 
tral plant  with  several  subdivisions. 

I  look  for  improvements  in  the  preliminary  treatment  of  sewage  to  lessen  mate- 
rially the  odors  sometimes  attending  sprinkling  filters.  For  certain  thickly  populated 
districts  I  believe  contact  beds  are  entitled  to  careful  consideration. 

The  lessening  of  odors  requires  primarily  the  prevention  of  putrefactive  conditions 
becoming  established  in  the  unfiltered  sewage  by  aeration,  oxidizing  chemicals  and 
probably  to  some  extent  the  application  of  sewage  so  as  to  minimize  the  opportunity  for 
wind  action  to  transport  sewage  spray. 

Aeration.  I  look  upon  aeration  as  a  promising  means  of  guarding  against  putre- 
faction. If  conditions  arise  where  it  is  necessary  to  deal  with  sewage  which  has  to 
some  extent  undergone  putrefaction,  I  consider  it  possible  that  organic  matter  to  a  lim- 
mited  extent  may  be  reduced  through  oxidation  by  air.  Except  for  limited  quantities 
of  unstable  organic  substances,  aeration  cannot  be  counted  upon  as  an  oxidizing  agent 
in  practice.    It  provides  molecular  oxygen,  whereas  the  bulk  of  the  organic  matter  of 


REPORT  OF  GEORGE  W.  FULLER 


209 


sewage  is  oxidized  only  by  the  atomic  oxygen  of  certain  powerful  oxidizing  agents,  or 
the  slow  oxidization  effected  through  bacterial  action. 

The  function  of  aeration  is  essentially  one  of  artificially  prolonging  the  period  of 
decomposition  of  sewage  on  an  inoffensive  aerobic  basis.  It  may  be  that  conditions  will 
arise  where  the  occasional  application  of  air  by  artificial  means  will  permit  the  dilution 
method  to  be  employed,  whereas  without  aeration  or  some  similar  treatment  the  dilu- 
tion method  would  present  objectionable  and  offensive  shortcomings. 

On  the  score  of  cost  the  aeration  method  for  general  use  does  not  look  promising; 
and  this  is  particularly  true  of  the  New  York  conditions  where  the  sewage  oscillates 
back  and  forth  for  a  period  of  time  that  makes  a  demand  on  the  atmospheric  oxygen 
greater  than  is  the  case  with  many  flowing  inland  streams. 

Oxidizing  Chemicals.  The  cost  of  applying  such  chemicals  as  liquid  chlorine  and 
hypochlorite  of  lime  or  of  soda  is  prohibitive  on  account  of  the  relatively  small  amount 
of  organic  matter  that  is  oxidized.  The  true  function  of  such  agents  is  the  killing  of 
bacteria,  and  within  certain  limits  they  are  useful  as  a  preservative  for  sewage  to  pre- 
vent decomposition  rather  than  to  effect  complete  ultimate  oxidation  of  the  non- 
settling  organic  matters. 

Electrolytic  Treatment.  A  good  deal  is  claimed  from  time  to  time  for  the  econom- 
ical advantages  derived  from  the  application  of  electricity  in  various  types  of  elec- 
trolytic cells  in  oxidizing  the  organic  matters  of  sewage.  In  particular  is  this  claimed 
where  the  current  may  be  applied  to  sea  water.  While  improvements  in  this  direction 
may  be  possible,  I  do  not  believe  that  they  are  promising  enough  to  warrant  considera- 
tion of  electrolytic  treatment  as  a  substitute  for  the  dilution  method. 

The  electrolytic  production  of  chemicals  to  precipitate  certain  colloidal  and  other 
non-settling  organic  matters  may  prove  desirable  in  the  future  and  worthy  of  adoption 
under  some  conditions.  This  method  would  be  used,  however,  in  conjunction  with 
settling  tanks,  and  could  be  employed  supplementary  to  such  tanks  without  requiring 
material  changes  in  the  design  of  tanks  built  for  plain  sedimentation  alone. 

Clarification 

The  purpose  of  clarification  devices  is  to  prevent  unsightly  sewage  solids  appearing 
in  the  diluting  water,  or  the  formation  of  sludge  banks  in  watercourses. 

Fine  Screens.  Fine  screens  afford  the  cheapest  way  of  removing  visible  objects 
of  sewage  origin  from  the  waters  receiving  sewage  where  such  screening  treatment 
alone  is  sufficient  for  obtaining  satisfactory  results.  Under  conditions  where  the  limit 
is  at  times  reached  in  the  amount  of  clarified  sewage  which  a  watercourse  will  oxidize 
satisfactorily,  settling  tanks  as  a  general  rule  are  cheaper  to  install  than  screens,  be- 
cause for  a  given  cost  they  will  remove  a  greater  quantity  of  organic  matter.  Where 
screens  will  suffice  for  a  term  of  years,  say  ten  or  more,  it  is  quite  possible  that  it  will 
prove  economical  to  install  screens  first,  to  be  followed  later  by  settling  basins  as  oc- 
casion demands. 

American  experience  with  fine  screens  is  quite  limited  and  not  altogether  satis- 
factory, owing  to  the  devices  requiring  much  attention  and  repair.  This  has  meant 
not  only  expense,  but  also  serious  interruptions  in  continuity  of  service. 

Screens  are  employed  to  much  better  advantage  in  Europe,  particularly  in  Ger- 
many. At  Dresden,  Frankfort  and  Hamburg  experiences  demonstrate  on  a  large  scale 
that  it  is  feasible  to  operate  moving  plate  screens  with  an  opening  as  small  as  0.04  inch. 
At  present  the  so-called  Reinsch  type  of  screen,  as  installed  at  Dresden,  seems  to  be 


210 


REPORTS  OF  EXPERTS 


most  popular.  It  is  of  the  disc  type  with  slots  about  0.085  inch  wide  and  1.25  inches 
long. 

As  fine  screens  come  into  service  in  America  I  look  for  marked  improvements  in 
continuity  of  service  and  freedom  from  expensive  repair  costs.  I  do  not  believe  their 
efficiency  will  be  any  greater  than  that  indicated  by  European  evidence  unless  it  should 
result  from  applying  to  screens  sewages  which  are  fresher  and  less  comminuted  than 
has  been  the  case  at  Dresden,  Frankfort  and  Hamburg. 

Settling  Tanks.  Sedimentation  for  a  two-hour  period  at  the  average  rate  of  sew- 
age flow  will  give  as  good  results  as  it  is  prudent  to  obtain  from  sedimentation.  For 
local  conditions  I  favor  single-story  tanks  with  hopper  bottoms,  as  it  is  undesirable  to 
septicize  the  sludge  at  its  point  of  origin. 

The  construction  of  settling  tanks  along  the  New  York  water  front  presents  some 
difficulties  on  account  of  the  high  cost  of  ground,  complications  from  salt  water  back- 
ing into  the  sewers  at  high  tide  and  the  necessity  of  caring  for  storm  flows.  I  believe 
these  difficulties  can  be  overcome  by  careful  engineering  study. 

Fine  Screens  vs.  Settling  Tanks.  My  views  have  been  already  indicated  in  the  fore- 
going paragraphs.  But  as  the  question  has  much  significance  here  in  New  York,  I  will 
state  that,  in  my  opinion,  screens  are  preferable  to  settling  tanks  only  where  it  is  de- 
sirable or  necessary  to  remove  only  relatively  large  sewage  matters  in  suspension. 
Where  settling  solids  would  form  deposits  in  the  watercourses  if  screening  alone  were 
adopted,  to  install  settling  tanks  will  prove  wiser  than  to  install  fine  screens.  Avail- 
able data  in  this  country  are  now  too  meager  to  allow  fine  lines  to  be  drawn  in  this 
comparison.  For  problems  of  this  magnitude  special  study  should  be  given  before  con- 
struction, not  only  of  the  relative  merits  of  the  two  systems  as  a  whole,  but  also  of  the 
local  conditions  at  each  main  sewer  outlet  or  groups  of  outlets  which  can  be  conve- 
niently united.  Both  screening  plants  and  settling  plants  can  be  operated  for  treat- 
ing fresh  sewage  without  creating  any  nuisance. 

Chemical  Precipitation.  The  use  of  coagulating  chemicals  has  been  known  for 
50  years  as  a  helpful  adjunct  in  removing  particles  of  suspended  matter  which  are 
so  fine  that  they  will  not  subside  in  ordinary  settling  tanks.  The  expense  of  the  added 
chemicals  and  the  large  increase  in  the  volume  of  the  resulting  sludge  is  such  that  as 
a  general  proposition  chemical  precipitation  is  not  worth  while. 

There  may  be  exceptional  conditions  where  plain  sedimentation  might  be  at  times 
inadequate  preparatory  to  the  discharge  of  sewage  into  some  arms  of  the  harbor,  and 
further  purification  then  resulting  from  the  application  of  chemicals  might  be  wise. 

Sludge  Disposal 

In  the  clarification  of  sewage  there  results  in  all  cases  a  substantial  quantity  of 
solid  matters  more  or  less  mixed  with  water  and  ordinarily  spoken  of  as  "sludge."  Ex- 
perience at  other  large  seaport  towns  employing  sewage  treatment  works,  such  as  Lon- 
don, Glasgow,  Manchester  and  Salford,  demonstrates  conclusively  that  the  barging  of 
sludge  to  the  open  sea  is  the  cheapest  way  of  disposing  of  the  sludge  without  nuisance. 

As  above  stated,  I  do  not  favor  septicization  of  the  sludge  along  the  water  front  in 
the  thickly  inhabited  districts  of  New  York.  In  this  respect  I  agree  with  the  Com- 
mission. 

Cases  may  arise  in  isolated  areas  removed  from  the  water  front  where  barging  to 
sea  will  not  be  desirable.   In  such  cases  I  advise  the  consideration  of  two-story  tanks  of 


REPORT  OF  GEORGE  W.  FULLER 


211 


the  Imhoff  type,  with  the  drying  of  the  sludge  on  drying  beds  so  that  the  residue  can  be 
carted  off  readily. 

Use  for  Fertilizer.  For  more  than  50  years  efforts  have  been  made  to  employ 
sewage  sludge  economically  as  a  fertilizer.  Rarely  if  ever  has  the  result  been  a  com- 
mercial success  when  operations  were  conducted  on  a  large  scale.  I  do  not  look  for 
any  substantial  change  in  the  future,  although  sewage  sludge  may  perhaps  be  employed 
as  a  "filler"  for  fertilizers.  In  such  event  it  is  safe  to  assume  that  the  users  of  the  ma- 
terial coming  from  settling  tanks  would  be  willing  to  prepare  it  for  their  processes, 
and  if  this  is  so  it  would  simply  mean  that  New  York  would  be  relieved  of  operating 
barges  to  sea  up  to  the  limits  to  which  sludge  is  diverted  to  fertilizer  purposes.  While 
some  slight  saving  in  the  operation  of  barges  may  be  accomplished  I  do  not  look  for 
any  substantial  compensation  to  the  city  from  fertilizer  manufacturers  who  might  use 
the  sludge  as  filler. 

Incineration.  I  am  aware  that  at  Frankfort,  Germany,  sewage  sludge  is  freed  of 
water  by  centrifuging  and  the  application  of  heat  in  revolving  drums,  so  that  the  dried 
sludge  may  be  burnt  with  other  city  refuse  in  an  adjoining  municipal  incineration 
plant.  While  this  procedure  may  have  a  future  for  inland  cities,  the  expense  will  never 
be  reduced  to  a  point  where  this  method  will  displace  barging  to  sea  for  the  sludge  of  a 
large  seaport  town. 

Destructive  Distillation.  In  a  small  way  there  are  some  data  available  as  to  the 
production  of  combustible  gases  and  coke  by  the  dry  distillation  of  sludge.  The  cost  of 
removing  the  water  is  so  great  that  the  future  will  never  see  this  treatment  become 
commercially  feasible. 

Sterilization.  With  the  existing  system  of  combined  sewers,  without  any  possibil- 
ity or  necessity  of  making  the  harbor  waters  of  a  ''drinking  water"  standard  of  purity, 
sterilization  for  the  great  bulk  of  the  New  York  sewage  need  never  be  seriously  consid- 
ered. 

For  some  of  the  outlying  areas  where  there  are  shell-fish  layings  or  bathing  beaches 
I  anticipate  a  resort  to  sterilization. 

Miscellaneous  Procedures 

From  time  to  time  attention  is  attracted  by  claims  for  unusual  efficiency  or  econ- 
omy or  both,  resulting  from  the  employment  of  special  types  of  strainers  or  other  clari- 
fying agents,  or  the  use  of  oxidizing  procedures  resulting  from  the  use  of  new  chemicals 
or  of  new  applications  of  electricity. 

Presumably  such  claims  will  be  heard  from  at  intervals  in  the  future,  and  it  may 
be  that  some  of  them  will  produce  more  effect  for  a  given  cost  than  could  now  be  at- 
tained. 

I  do  not  believe,  however,  that  the  business  aspects  of  the  New  York  problem  will 
ever  be  materially  modified  by  improvements  in  methods  or  devices  which  may  become 
available. 

As  time  advances  a  clearer  understanding  will  be  obtained  as  to  just  what  is  needed 
in  certain  of  the  subdivisions  and  the  progressive  installation  of  any  project  as  large  as 
the  New  York  sewage  disposal  problem  will  give  opportunity  to  adopt  in  the  designs 
the  current  improvements  which,  as  above  stated,  will  in  all  probability  relate  to  minor 
details  rather  than  to  underlying  principles. 


212 


REPORTS  OF  EXPERTS 


Conclusions  as  to  Program  Being  Considered  by  the  Commission 

I  have  carefully  considered  the  program  now  recommended  hy  the  Commission  as 
it  is  in  a  general  way  published.  Speaking  generally,  I  agree  with  the  Commission  as 
to  the  conclusions  arrived  at  for  those  portions  of  the  harbor  where  there  is  an  abun- 
dance of  water  for  disposing  of  clarified  sewage  by  dispersion  with  adequate  quantities 
of  water.  I  disagree,  however,  with  the  proposal  of  the  Commission  for  the  Lower 
East  river  and  Western  Jamaica  bay  divisions  to  divert  the  sewage  to  the  proposed 
"Outfall  island"  some  three  miles  south  of  Coney  Island.  I  will  briefly  outline  my 
conclusions  upon  these  two  separate  groups  of  procedures. 

A.    Agreement  on  Clarification  Program 

1.  I  agree  with  the  Commission  that  the  state  of  the  art  of  sewage  disposal  is  now 
such  as  to  warrant  the  adoption  of  a  definite  policy  for  that  portion  of  the  main  drain- 
age of  the  city  that  is  tributary  to  watercourses  containing  ample  water  for  dispersion 
of  clarified  sewage.  By  this  is  meant,  of  course,  the  territory  having  sewer  outlets  dis- 
charging particularly  into  the  Hudson  river,  the  Upper  bay,  the  portion  of  the  East 
river  above  Hell  Gate,  and  some  portions  of  the  Jamaica  bay  district. 

2.  Local  factors  should  determine  what  form  of  clarification  means  should  be  used. 
Where  screens  alone  are  sufficient  no  other  means  need  be  considered.  Where  a  greater 
degree  of  purification  is  desirable  I  am  inclined  to  favor  simple  sedimentation  with  the 
elimination  of  screening. 

A  close  decision  of  the  relative  merits  of  these  two  clarifjdng  processes  is  not  now 
called  for ;  it  is  a  matter  of  careful  engineering  detail,  properly  to  adapt,  in  each  case, 
the  means  used  to  the  conditions  of  use  and  the  end  to  be  attained. 

3.  Such  local  clarification  plants  can  be  operated  on  the  banks  of  the  Hudson  river, 
or  wherever  else  installed,  without  offense  to  the  inhabitants  of  the  neighborhood. 

4.  I  am  in  accord  with  the  Commission's  proposal  to  disperse  the  clarified  sewage 
in  deep  water  through  submerged  outlets,  where  such  dispersal  is  shown  to  be  necessary. 

5.  I  agree  with  the  Commission  that  it  is  proper  to  consider  that  the  sludge  and 
screenings  from  the  clarification  plants  can  be  most  advantageously  disposed  of  by 
barging  to  sea.  Two-story  tanks  of  the  Imhoff  type  as  compared  with  single-story 
tanks  of  the  so-called  Dortmund  type  are  not  justifiable  on  the  ground  of  cost  and  for 
the  further  reason  that  fresh  sludge  frequently  removed  could  be  more  advantageously 
disposed  of  at  sea  than  would  septicized  sludge. 

6.  As  a  practical  business  procedure,  I  attach  importance  to  the  fact  that  these 
clarification  works  can  be  installed  progressively  as  funds  are  made  available,  and 
would  naturally  be  commenced  at  points  where  pollution  is  greatest. 

B.    Opinion  as  to  Outlet  Island 

7.  I  agree  with  the  Commission  that  the  sewage  of  the  Lower  East  river  district 
could  be  satisfactorily  disposed  of  by  diversion  to  a  proposed  island  some  three  miles 
south  of  Coney  Island  and  about  one-third  of  a  mile  north  of  Ambrose  channel.  Such 
a  project  as  described  in  Preliminary  Report  VI  is  estimated  by  the  Commission  to  cost 
in  round  numbers  some  f22,000,000,  of  which  about  one-sixth  is  estimated  to  be  owing 
to  provisions  made  for  the  sewage  from  a  portion  of  the  Jamaica  bay  division.  A  tun- 
nel some  12  miles  in  length  beyond  the  Wallabout  pumping  station  would  require  a 
period  of  transit  such  as  to  make  it  highly  important  to  aerate  and  sterilize  the  sewage 


REPORT  OF  GEORGE  W.  FULLER 


213 


so  that  it  will  not  have  undergone  decomposition  to  a  point  of  producing  offensive  odors 
by  the  time  it  has  traveled  to  "Outfall  island.''  From  the  information  given  as  to  the 
mixing  of  the  sewage  with  the  sea  water,  ow  ing  to  the  action  of  the  breakers  in  the 
relatively  shallow  water,  I  do  not  anticipate  that  clarified  sewage  would  produce  de- 
posits or  in  any  other  way  produce  a  nuisance. 

I  do  not  consider  such  a  site  suitable  for  sprinkling  filters,  but  it  is  my  conclusion, 
as  it  is  that  of  the  Commission,  that  such  will  never  be  necessary  for  the  sewage  of  the 
Lower  East  river  district. 

8.  While  agreeing  as  to  the  general  feasibility  of  the  "Outlet  island  project"  for 
the  disposal  of  the  sewage  of  the  Lower  East  river  district,  I  do  not  agree  on  the  neces- 
sity of  going  to  so  great  an  expense  in  treating  the  sewage  from  the  area  in  question. 

9.  I  am  of  the  opinion  that  the  Commission's  standard  of  residual  dissolved 
oxygen  is  unreasonably  severe ;  a  residual  quantity  of  1.5  cubic  centimeters  per  liter, 
one-half  of  the  amount  of  your  standard,  is  safe  for  adoption  under  proper  conditions. 
Such  proper  conditions  are  that  sewage  sludge  shall  not  be  allowed  to  accumulate  to 
such  an  extent  as  to  become  a  serious  factor  in  absorbing  oxygen  from  the  water. 

Appended  to  my  report  is  a  memorandum  explaining  in  more  detail  my  view-s  on 
the  question  of  residual  oxygen. 

10.  My  preliminary  studies  indicate  to  me  that  the  investment  cost  of  the  "Out- 
let island''  project  for  the  Lower  East  river,  as  estimated  by  the  Commission  in  its  Pre- 
liminary Report  VI  is  about  four  times  as  high  as  sedimentation  plants  for  the  same 
district.  The  annual  charge,  fixed  and  operating,  will  be  for  the  "Outlet  island"  project 
about  twice  as  high  as  for  sedimentation  plants. 

11.  Unquestionably  the  Lower  East  river  is  able  to  digest  the  sewage  from  a  large 
population  without  being  objectionably  affected,  and  I  am  of  the  opinion  that  the  East 
river  will  absorb  the  clarified  sewage  from  the  populations  actually  tributary  to  it 
for  a  great  many  years  to  come.  While  the  improvement  effected  by  entirely  removing 
the  sewage  is  materially  greater  than  that  effected  by  sedimentation  plants,  the  lat- 
ter will,  on  the  standard  which  I  consider  ample,  serve  all  required  ends.  They  wall, 
too,  accomplish  at  least  as  much  improvement  for  each  dollar  expended  as  would  the 
distant  disposal  method. 

12.  These  East  river  clarification  plants  can  be  expected  to  be  unobjectionable  to 
public  sentiment,  as  well  as  the  plants  on  the  Hudson  river  and  elsewhere. 

13.  If  at  some  future  time  it  should  prove  desirable  to  divert  some  of  the  sewage 
from  areas  naturally  tributary  to  the  Lower  East  river  to  some  point  such  as  the  pro- 
posed Outlet  island,  such  partial  diversion  can  then  be  more  economically  effected  than 
an  immediate  removal  of  the  Lower  East  river  drainage  as  a  w7hole. 

Very  truly  yours, 

October  15,  1913.  George  W.  Fuller. 

Appendix  to  Mr.  Fuller's  Report 

.  memorandum  of  views  in  opposition  to  the  proposed  standard  of  a  minimum  dis- 
solved OXYGEN  CONTENT  OF  THREE  CUBIC  CENTIMETERS  PER  LITER  OF  NEW  YORK 
HARBOR  WATER 

Having  already  stated  my  conclusion  that  a  proper  general  residual  dissolved  oxy- 
gen content  of  the  New  York  harbor  waters  can  be  safely  placed  as  low7  as  one-half  of 
that  proposed  by  the  Commission,  I  shall  now7  proceed  to  outline  briefly  some  of  the 


214 


REPORTS  OF  EXPERTS 


evidence  which  leads  me  to  conclude  that  1.5  cubic  centimeters  per  liter,  equal  roughly 
to  2.1  parts  per  million,  or  roughly  30  per  cent,  of  saturation  for  New  York  harbor 
water  in  summer,  is  a  sufficient  residual  quantity. 

As  already  intimated  in  this  report,  consideration  of  the  requirements  of  fish  life 
and  lack  of  data  as  to  the  significance  of  putrefying  sludge  deposits  have  led  to  conclu- 
sions that  are  not  safe  deductions  from  the  information  available. 

Messrs.  Black  and  Phelps  in  their  report  to  the  Board  of  Estimate  and  Apportion- 
ment, March,  1911,  proposed  a  standard  of  70  per  cent,  residual  dissolved  oxygen  for 
the  New  York  harbor  waters  and  stated  this  limit  to  be  needed  for  major  fish  life. 
The3r  stated  further  that  some  forms  of  fish  life  can  exist  with  a  dissolved  oxygen  con- 
tent of  30  per  cent,  of  that  required  for  saturation  and  expressed  the  view  that  50  per 
cent,  is  a  limit  below  which  a  stream  may  become  turbid  and  noisome  and  that  below  30 
per  cent,  the  stream  constitutes  a  nuisance. 

I  have  noted  that  the  Commission  has  obtained  the  views  of  some  ten  or  more 
sanitary  experts  with  respect  to  the  dissolved  oxygen  standard,  and  as  stated  in  the 
published  reports  of  the  Commission  all  but  two  or  three  of  these  experts  have  expressed 
their  acquiescence  in  the  minimum  limit  of  50  per  cent,  saturation  or  more.  The  re- 
maining experts  expressed  no  opinion  upon  the  matter,  so  that  your  advisers  up  to 
this  time  have  in  no  instance  advocated  a  residual  percentage  of  less  than  50  per  cent, 
of  saturation. 

Those  familiar  with  bio-chemical  activities  will  agree  that  theoretically  no  objec- 
tionable offensive  products  of  decomposition  can  arise  in  sewage-polluted  waters  so 
long  as  some  oxygen  exists  at  all  times  and  in  all  places  in  the  water  and  upon  the 
bottom  and  sides  of  its  container.    So  much  for  theory. 

In  practice  it  is  found  that  a  margin  of  safety  must  be  provided.  Some  particles 
of  suspended  matter  of  sewage  origin  obviously  must  be  present  in  all  sewage-polluted 
waters  (and  frequently  on  stream  beds)  and  that  within  the  interior  and  upon  the  sides 
of  these  suspended  particles  it  must  be  recognized  that  there  are  present  bacteria  com- 
ing from  the  abdominal  tract  of  those  voiding  fecal  particles  and  are  likely  to  continue 
to  live  on  an  anaerobic  basis.  In  particular  is  this  true  of  organisms  within  the  in- 
terior of  colloidal  or  suspended  particles,  notwithstanding  that  the  exterior  surfaces  of 
such  particles  are  surrounded  with  water  containing  dissolved  oxygen. 

Laboratory  experiments  show  in  the  course  of  the  so-called  incubation  or  putresci- 
bility  tests  that  samples  of  polluted  liquid  may  turn  black  and  even  give  off  offensive 
odors  while  there  is  still  present  a  measurable  quantity  of  dissolved  oxygen.  As  sus- 
pended particles  of  organic  fecal  matters  (or  sludge  deposits)  undergo  bacterial  de- 
composition, they  may  release  products  in  a  soluble  or  gaseous  form  which  rise  to 
the  surface  of  the  overlying  water,  produce  objectionable  odors,  discolor  the  water, 
bringing  about  these  results  in  the  presence  of  dissolved  oxygen. 

In  small  single-story  septic  tanks  it  is  possible  to  find  the  effluent  of  such  tanks  con- 
taining a  high  content  of  dissolved  oxygen  and  at  the  same  time  the  putrefying  sludge 
deposits  give  off  offensive  odors  and  behave  in  other  ways  fairly  indicative  of  septici- 
zation.    Compare  the  data  in  my  book  on  ''Sewage  Disposal,"  page  493. 

Settling  tanks  receiving  the  effluent  of  sprinkling  filters  or  contact  beds  likewise 
may  contain  a  high  dissolved  oxygen  content  as  the  settled  effluent  is  analyzed,  but  at 
the  same  time  rapid  gasification  may  be  taking  place  in  the  deposited  sludge  upon  the 
floor  of  the  settling  basin  to  an  extent  that  causes  gas-lifted  particles  to  appear  with 
the  effluent  as  the  latter  leaves  the  outlet  of  the  tank. 


REPORT  OF  GEORGE  W.  FULLER 


215 


In  many  watercourses  there  is  to  be  noted  in  either  fresh  or  salt  water  a  black  dis- 
colored appearance  and  the  production  of  more  or  less  offensive  odor,  even  where  the 
overlying  water  contains  a  substantial  quantity  of  atmospheric  oxygen. 

The  question  then  becomes,  "What  is  the  margin  of  safety  that  it  is  wise  to  em- 
ploy?" 

I  assume  that  a  substantial  portion  of  the  sludge  will  be  removed  from  the  sew- 
age that  in  the  future  will  enter  the  harbor  waters;  also  that  by  dredging  and  by  the 
exhaustion  through  bacterial  action  the  organic  contents  of  sludge  now  found  in  the 
harbor  and  the  adjacent  watercourses  will  be  materially  reduced. 

There  are  some  instances  where  practical  observations  show  on  a  large  scale  the 
relation  between  dissolved  oxygen  and  the  presence  or  absence  of  offensive  putrefac- 
tive conditions.  It  is  such  data  as  these  that  I  consider  are  the  most  trustworthy  guide 
to  what  should  be  used  as  a  working  standard  under  New  York  harbor  conditions. 

It  is  the  experiences  of  the  Lower  Thames  river  in  the  general  vicinity  of  the  outlets 
of  the  London  sewers  which  for  30  years  have  afforded  the  most  comprehensive  data  in 
regard  to  a  criterion  for  residual  dissolved  oxygen  content. 

Prior  to  the  commencement  of  the  operation  of  the  Barking  creek  chemical  precip- 
itation plant  at  the  northern  London  outfall  in  1889  and  of  the  corresponding  plant  at 
Crossness  at  the  southern  outfall  in  1891,  seriously  offensive  odors  arose,  especially 
during  the  summer.  So  bad  were  these  conditions  that  during  the  period  of  construc- 
tion in  the  late  eighties  it  became  necessary  at  times  to  employ  hypochlorite  of  lime 
and  permanganate  of  soda  and  other  chemicals  as  deodorants. 

For  more  than  20  years  reasonably  satisfactory  results  in  the  Lower  Thames  have 
been  obtained  as  a  result  solely  of  the  removal  of  some  of  the  suspended  organic  mat- 
ter by  chemical  precipitation.  The  bed  of  the  river  was  thus  relieved  from  the  forma- 
tion of  new  umud  banks''  or  sludge  deposits,  while  the  old  mud  banks  gradually  became 
inert  or  were  removed  by  dredging  or  by  scouring  velocities  at  times  of  flood  flows. 

The  two  principal  technical  advisers  in  the  adoption  of  the  chemical  precipitation 
works  for  London  were  Mr.  W.  J.  Dibden  and  the  late  Dr.  A.  Dupre.  The  latter  stated 
his  views  on  page  88  of  Vol.  CXXIX  of  the  Proceedings  of  the  Institution  of  Civil 
Engineers  of  Great  Britain,  as  follows: 

"In  his  experience  the  amount  of  oxygen  which  remained  in  the  river  formed 
the  best  means  of  judging  the  action  of  the  river.   If  the  river  was  pure,  it  was 
fully  aerated ;  if  it  became  foul,  the  fouler  it  was  the  less  the  amount  of  aeration, 
and  it  was  most  extraordinary  how  by  means  of  the  oxygen,  every  foul  stream 
that  came  into  it  could  be  found.    When  Mr.  Dibden  and  he  were  at  Erith  they 
could,  after  the  first  day,  find  out  the  hour  of  the  tide  by  means  of  the  oxygen 
dissolved  in  the  water,  and  could  find  out  the  sewage  stream  from  Barking  by 
means  of  the  analyses  of  oxygen  absorbed  even  before  the  eye  noticed  it.  The 
oxygen  absorbed  allowed  them,  so  to  speak,  to  feel  the  pulse  of  the  river;  as 
long  as  the  oxygen  remained  about  25  per  cent,  or  30  per  cent,  of  the  possible 
total  there  was  no  fear  of  any  harm." 
Mr.  Dibden  in  same  publication  from  which  I  quote  as  above  from  Dr.  Dupre, 
states  very  clearly  on  pages  47  and  53  his  belief  in  the  adequacy  of  the  chemical  precip- 
itation plants  in  freeing  the  river  Thames  from  pollution. 

In  the  third  edition  of  Mr.  Dibden's  book  on  "The  Purification  of  Sewage  and 
Water,"  published  in  1903,  the  oxygen  content  as  related  to  the  London  problem  is  dis- 
cussed at  some  length  on  pages  218-20  and  on  pages  297-300.    Here  his  opinion  is 


216 


REPORTS  OF  EXPERTS 


made  plain  that  fish  life  would  be  in  no  way  interfered  with  provided  the  degree  of 
aeration  at  no  time  fell  below  50  per  cent,  of  that  required  to  saturate  the  water.  While 
he  refers  to  the  need  of  further  experiences,  he  states  that  no  evil  results  need  be  ap- 
prehended if  the  degree  of  aeration  does  not  fall  below  50  per  cent.,  but  he  does  not  in 
any  way  state  a  safe  minimum  from  the  standpoint  of  nuisance  only.  Reference  is 
made  to  the  fish  question  in  terms  indicating  the  belief  that  there  is  very  little  chance 
of  fish  thriving  in  the  water  when  the  percentage  of  aeration  falls  below  50  per  cent., 
and  that  when  it  falls  below  30  per  cent,  it  is  certain  that  no  fish  can  live.  His  view- 
point seems  to  depend  wholly  on  the  question  of  what  is  the  oxj'gen  content  necessary 
to  support  fish  life  and  if  additional  purification  were  necessary  the  feasibility  of  se- 
curing that  end  in  the  Lower  Thames  by  adopting  a  final  purification  for  the  chemically 
precipitated  London  sewage  by  coke  beds  operated  on  a  contact  basis  as  devised  by  Mr. 
Dibden  himself  at  the  testing  plant  at  Barking  creek. 

Prof.  Frank  Clowes,  the  successor  of  Mr.  Dibden  as  chemist  of  the  London  County 
Council,  is  more  explicit  in  his  views,  which  are  in  substantial  conformity  with  those 
of  Dr.  Dupre  as  noted  in  the  testimony  of  Prof.  Clowes  given  in  July,  1903,  before 
the  Royal  Commission  on  Sewage  Disposal,  Fourth  Report,  Vol.  II,  Minutes  of  Evi- 
dence, page  113.  Asked  in  question  18,723  whether  the  almost  entire  removal  of  dis- 
solved oxygen  from  the  Lower  Thames  water  brings  about  actual  nuisance,  his  reply 
was  as  follows : 

"I  should  say  that  the  aeration  of  the  river  water  would  be  at  its  minimum 
in  the  immediate  neighborhood  of  the  outfalls;  for  some  miles  above  or  below 
this  the  average  aeration  would  be  something  like  20  or  30  per  cent.  At  times 
it  falls  to  5  per  cent,  of  the  possible,  and  it  is  then  geeting  very  near  the  limit 
where  the  oxygen  would  disappear.  When  once  the  dissolved  oxygen  disappears 
the  change  of  the  organic  substances  in  the  river  water  may  become  an  offensive 
one,  especially  in  hot  weather.  It  is  of  a  different  character  in  the  absence  of 
oxygen  and  causes  offense.  This  has  occurred  in  the  summer  in  the  neighbor- 
hood of  Woolwich  and  Greenwich.  There  was  an  offensive  smell  from  the  river, 
which,  if  it  had  continued,  would  have  caused  us  to  take  special  remedial  steps." 
Later  in  the  same  testimony,  question  18,733,  Prof.  Clowes  states,  in  answer  to 
a  question  asking  as  to  the  creation  practically  of  a  nuisance,  that : 

"This  occurs  very  exceptionally  indeed.  I  have  only  had  one  case  in  my 
own  experience." 

In  October,  1912,  Sir  Maurice  Fitzmaurice,  then  Chief  Engineer  of  the  London 
County  Council,  in  a  special  report  on  the  Main  Drainage  of  London,  has  reviewed 
an  earlier  report  of  his,  dated  May,  1909,  in  which  with  respect  to  the  condition  of  the 
Lower  Thames  he  states: 

"The  conclusions  which  I  came  to  in  the  report  to  the  Main  Drainage  Com- 
mittee in  December,  1909,  in  my  opinion  still  (October,  1912)  hold  good,  namely, 
the  state  of  the  river  is  at  the  present  time  not  such  as  to  necessitate  the  imme- 
diate further  purification  of  London  sewage,  and  I  do  not  think  it  will  necessi- 
tate it  for  some  years  to  come." 
Sir  Maurice  Fitzmaurice  continues  his  report  by  referring  to  special  experiences 
obtained  from  May  to  August,  inclusive,  1911,  when  the  application  of  lime  and  iron 
was  omitted  at  the  northern  outfall  at  Barking.   During  this  whole  period 

"no  complaint  was  received  as  regards  the  condition  of  the  Thames,  notwith- 
standing that  the  summer  of  1911  was  exceptionally  hot  and  the  amount  of  river 
water  coming  down  was  exceptionally  small." 


REPORT  OF  GEORGE  W.  FULLER 


217 


These  experiments  were  repeated  June  to  August,  1912,  with  corroborative  results. 
He  recommends  that  at  one  of  the  outfalls  operations  should  be  conducted  for  one  year 
completely  without  chemicals,  which  might  result  in  a  somewhat  less  complete  precip- 
itation of  the  suspended  organic  matters  in  the  raw  sewage. 

As  the  London  problem  has  a  number  of  features  in  common  with  the  one  at  New 
York,  and  in  view  of  the  long-continued  studies  made  of  the  Lower  Thames  conditions, 
they  are  of  more  significance  than  many  other  available  data  secured  at  Berlin,  Ham- 
burg, Chicago,  Columbus  and  Lawrence,  because,  as  in  the  case  of  New  York  harbor, 
they  deal  with  tidal  estuary  waters  which  contain  a  substantial  proportion  of  salt  and 
other  constituents  entering  on  the  incoming  tides  from  the  ocean. 

Mention  is  made  of  the  admixture  of  sea  water  at  this  time  because  of  the  fact  that 
where  anaerobic  decomposition  takes  place  in  certain  small  portions  of  a  volume  of 
sewage-polluted  sea  water,  sulphides  and  sulphureted  hydrogen  may  form  through  re- 
ducing action  taking  place  upon  the  sulphate  of  lime  with  a  consequent  production  of 
foul  odors,  and  reducing  the  dissolved  oxygen  content  in  a  water  which  on  an  average 
might  show  initially  a  higher  percentage  saturation  than  a  similarly  polluted  land 
water. 

Indeed,  if  this  were  a  question  dealing  with  the  capacity  of  land  water  to  digest 
sewage,  I  should  feel  disposed  towards  reducing  your  proposed  standard  of  3  cubic 
centimeters  per  liter  to  1  cubic  centimeter  per  liter.  The  latter  figure  is  too  low  to 
allow  of  fish  life  to  thrive.  Notwithstanding,  it  is  my  opinion  that  a  loss  of  fishing 
grounds  in  parts  of  the  harbor  which  otherwise  are  kept  reasonably  clean,  both  of  sus- 
pended matter  and  sewage  deposits,  is  justifiable  if  such  means  the  saving  of  many  mil- 
lions of  dollars. 

I  am  also  aware  of  the  limited  evidence  available  on  the  amount  of  oxygen  neces- 
sary to  support  salt  water  fish  and  that  it  is  not  a  fair  inference  to  conclude  that  the 
oxygen  necessary  for  satisfactory  maintenance  of  fish  life  for  certain  land  water 
streams  is  a  criterion  for  tidal  estuaries  containing  a  substantial  quantity  of  sea  water. 

While  dissolved  oxygen  figures  of  land  waters  may  indicate  conditions  differing 
from  those  obtaining  where  the  same  dissolved  oxygen  content  appears  in  sea  water, 
still  such  observations  must  be  given  due  weight. 

In  the  Royal  Commission  on  Sewage  Disposal,  Eighth  Report,  Vol.  II,  Appendix, 
page  111,  I  note  the  statement  to  the  effect  that  a  fishy  smell  usually  accompanies  a  con- 
dition of  deoxygenation  equal  to  a  reduction  to  3  cubic  centimeters  of  oxygen  per  liter, 
which  can  only  obtain  in  a  slow-flowing  stream  which  is  polluted  with  a  considerable 
quantity  of  effluent  or  a  lesser  quantity  of  sewage.  A  study  of  the  tabulated  field  obser- 
vations, which  are  presumably  the  basis  of  this  conclusion,  pages  1-15,  shows  that 
there  is  no  such  condition  of  fishy  smell  recorded.  Possibly  bottled  samples  tested  at 
the  laboratory  did  show  this  smell. 

In  this  same  volume,  page  135,  I  note  a  summary  of  155  tests  for  dissolved  oxy- 
gen in  river  water  classed  from  "very  clean"  to  "bad."  The  figures  thus  summarized 
do  not  indicate  a  more  consistent  relation  between  the  oxygen  content  and  the  water 
condition  as  to  nuisance  than  the  tables  of  observations  given  earlier  in  this  volume, 
pages  1-51.  The  range  from  minimum  to  average  is  so  wide  that  it  is  quite  possible 
that  the  observations  of  conditions  are  based  on  figures  not  recorded.  Besides,  no  ac- 
count is  taken  of  the  effect  of  putrefying  sludge  deposits,  which  may  be  exerting  a 
more  objectionable  influence  than  the  dissolved  oxygen  content. 

On  the  other  hand,  many  important  observations  have  been  made  at  Chicago, 


218 


REPORTS  OF  EXPERTS 


Columbus,  Lawrence,  Berlin,  Hamburg  and  other  places,  showing  satisfactory  river 
water  conditions  to  be  fully  consistent  with  very  low  dissolved  oxygen  content. 

I  wish  finally  to  emphasize  strongly  the  lessons  to  be  read  from  the  London  experi- 
ences with  the  Lower  Thames.  There,  starting  some  25  years  ago  with  a  noisome  river, 
with  oxygen  often  exhausted  during  the  summer,  and  with  much  of  the  bottom  and 
banks  covered  with  foul  sludge  deposits,  the  installation  of  simple  sedimentation 
methods,  aided  by  a  very  moderate  addition  of  chemicals,  has  for  25  years  served  the 
purpose  and  is  still  sufficient.  In  spite  of  the  large  increase  of  tributary  population 
during  this  period  and  the  corresponding  increase  of  organic  sewage  content,  the 
sludge  banks  are  reduced  and  the  river  improved  to  a  satisfactory  condition ;  and  this 
with  an  oxygen  content  far  below  the  standard  of  3  cubic  centimeters  per  liter  the 
Commission  has  suggested  for  the  waters  of  New  York  harbor. 

CORRESPONDENCE  CONTAINING  MR.  FULLER'S  ENDORSEMENT  OF  THE  COMMISSION'S  RECOM- 
MENDATION FOR  THE  GRADUAL  CONSTRUCTION  OF  THE  LOWER  EAST  RIVER  PROJECT 

March  16,  1914. 

George  W.  Puller,  Esq., 

170  Broadway,  New  York  City. 

Dear  Sir:  Since  your  report  of  October,  1913,  was  submitted,  some  of  the  opinions 
and  projects  relating  to  sewage  disposal,  upon  which  that  report  was  based  have  been 
so  altered  in  preparation  for  this  Commission's  final  report  that  it  seems  desirable  to 
bring  the  changes  to  your  attention  and  to  ask  your  opinion  in  regard  to  them. 

The  changes  made  affect  the  minimum  percentage  of  dissolved  oxygen  permissible 
for  the  water  and  the  Commission's  plan  for  the  protection  of  the  Lower  East  river. 
These  are  the  only  two  subjects  upon  which  you  were  not  in  substantial  accord  with 
the  Commission's  views  when  your  report  was  made. 

With  respect  to  the  oxygen  question,  this  Commission  considers  that  it  will  not 
be  necessary  to  include  a  restriction  as  to  oxygen  in  the  standard  of  cleanness  which 
should  be  established  as  a  guide  in  protecting  the  harbor  against  sewage,  for  if  the 
other  provisions  of  the  standard  are  complied  with,  there  will,  in  the  opinion  of  the 
Commission,  be  sufficient  oxygen  in  the  water  to  answer  the  requirements. 

With  respect  to  the  plan  for  the  Lower  East  river,  the  Commission  expects  to 
recommend  that  the  same  principle  of  gradual  construction  be  adopted  in  building  the 
main  drainage  and  disposal  works  which  will  be  necessary  for  the  Lower  East  river  as 
the  Commission  has  advised  in  the  projects  which  it  has  proposed  for  other  parts  of 
the  city.  Instead  of  carrying  out  the  ocean  island  project  with  its  interceptors,  siphon, 
pumping  station,  main,  island  and  settling  basin  disposal  plant  as  one  undertaking, 
only  the  first  stages  in  the  execution  of  this  comprehensive  plan  would  be  undertaken 
in  the  near  future. 

The  works  to  be  taken  in  hand  at  first  would  be,  for  Manhattan,  an  intercepting 
sewer  running  along  the  Manhattan  water  front  from  the  Battery  at  the  south  and 
26th  St.  at  the  north  to  a  point  near  Broome  St.,  where  a  screening  and  pumping 
station  would  be  located.  The  screens  would  operate  upon  the  most  efficient  principle 
for  fine  screens.  The  sewage,  after  screening,  would  be  discharged  well  out  from  shore 
at  the  bottom  of  the  river  through  multiple  outlets. 

On  the  Brooklyn  side,  the  sewage  would  be  collected  by  an  interceptor  from  Clas- 
aon  Ave.  at  the  south  to  Newtown  Creek  at  the  north  to  a  point  near  South  8th  St., 


REPORT  OF  GEORGE  W.  FULLER 


219 


where  it  would  be  passed  through  screens  like  those  on  the  Manhattan  side  of  the  river 
and  pumped  through  submerged  outfalls  lying  on  the  river  bottom  to  a  distance  suffi- 
ciently far  from  shore  to  insure  immediate  and  thorough  diffusion. 

The  sewage  from  the  rest  of  the  Lower  East  river  territory  in  Manhattan  and 
Brooklyn  would  be  collected  for  screening  and  discharge  probably  to  as  many  points 
as  there  were  subdivisions  or  principal  drainage  areas.  When,  after  these  works  are 
carried  out,  it  is  found  necessary  or  desirable  to  afford  further  protection  to  the  Lower 
East  river,  the  city  can  proceed  to  construct  the  siphon  to  carry  the  sewage  of  Lower 
Manhattan  beneath  the  East  river  to  the  Brooklyn  shore,  where,  after  joining  the  sew- 
age from  the  screening  plant  at  South  8th  St.,  it  would  be  pumped  to  sea. 

In  the  final  development  of  this  plan,  it  will  be  necessary  to  construct  the  pumping 
station  on  the  Brooklyn  side,  the  main  to  the  ocean  outlet  and  the  island,  where  the 
sewage  will  be  treated  before  final  disposition.  No  part  of  the  original  construction 
will  have  to  be  discarded  except  the  submerged  outfalls. 

The  Commission  believes  that  the  idea  of  proceeding  in  the  manner  indicated  to- 
ward the  gradual  and  ultimate  construction  of  the  ocean  island  project  may  meet  with 
your  approval,  inasmuch  as  you  consider  that  it  will  not  be  necessary  to  divert  a  large 
amount  of  sewage  from  the  Lower  East  river  and  that  screening  and  discharging  the 
sewage  beneath  the  deep,  strong  currents  of  the  East  river  will  permanently  meet  the 
requirements  of  the  situation.  The  Commission  is  of  opinion  that  the  ocean  island 
project  will  be  recognized  as  a  necessity  before  many  years  and  is  willing  to  leave  the 
correctness  of  its  opinion  or  of  your  judgment  to  be  determined  by  experience. 

If  it  never  becomes  necessary  to  build  the  siphon  between  Manhattan  and  Brook- 
lyn and  carry  the  sewage  to  a  distant  point  for  disposal,  the  stage  of  construction 
which  the  Commission  is  now  preparing  to  recommend  and  which  it  is  hoped  you  will 
approve  of  can  be  left  as  the  completed  work. 

Very  sincerely, 

(Signed)       George  A.  Soper, 

President. 

March  17,  1914. 

Dr.  George  A.  Soper,  President, 

Metropolitan  Sewerage  Commission, 

17  Battery  Place,  New  York  City. 
Dear  Sir:  I  beg  to  acknowledge  receipt  of  your  letter  of  March  16th. 
I  understand  that  your  studies  of  the  past  few  months  have  led  you  to  make  certain 
changes  in  your  program  for  the  protection  of  the  Lower  East  river,  and  that  the 
recommendations  that  you  now  propose  to  make  are: 

1.  That  the  minimum  percentage  of  dissolved  oxygen  in  the  harbor  water  as  one 
of  the  specifications  of  the  standard  of  cleanliness  be  eliminated. 

2.  That  instead  of  building  the  proposed  outlet  island  in  the  Atlantic  ocean  in  the 
immediate  future,  you  would  have  the  sewage  naturally  tributary  to  the  Lower  East 
river  collected  at  certain  selected  points  and  there  subject  it  to  fine  screening  and  dis- 
charge it  through  submerged  outfalls  at  suitable  points  in  the  river  bottom. 

3.  That  present  construction  be  adapted  to  use  in  connection  with  the  outlet 
island  project,  but  with  the  need  for  the  use  of  the  latter  project  to  be  investigated 
and  determined  after  the  completion  of  the  works  now  recommended. 


220 


REPORTS  OF  EXPERTS 


4.  That  further  construction  beyond  that  stated  in  Paragraph  2  be  deferred  until 
the  need  is  determined. 

I  fully  agree  that  these  recommendations  are  proper  ones. 

Yours  respectfully, 

(Signed)       George  W.  Fuller. 

SECTION  IV 

REPORT  OF  RUDOLPH  BERING,  C.  E.,  Sc.  D. 

Metropolitan  Sewerage  Commission  of  New  York, 

Dr.  Geo.  A.  Soper,  President,  New  York  City. 
Gentlemen  :  On  July  22,  1913,  Dr.  Geo.  A.  Soper,  President,  Metropolitan  Sew- 
erage Commission,  addressed  a  letter  to  me,  from  which  I  quote  as  follows : 

"I  am  authorized  to  request  you  to  make  a  report  on  the  work  of  the  Metro- 
politan Sewerage  Commission  of  New  York.  The  ground  to  be  covered  is  the 
necessity  and  sufficiency  of  the  plans  which  the  Commission  has  proposed  for 
the  disposal  of  New  York's  sewage.  It  is  expected  that  your  study  will  include 
an  examination  of  this  Commission's  reports,  and  other  data,  and  a  considera- 
tion of  the  principles  upon  which  the  plans  are  being  prepared. 

"Facilities  will  be  afforded  you  to  become  familiar  with  the  conditions  which 
exist  and  which  may  reasonably  be  expected  in  the  future,  and  to  understand  the 
opinions  and  policies  which  have  guided  the  Metropolitan  Sewerage  Commis- 
sion throughout  its  work." 
In  accordance  with  this  request  I  respectfully  present  the  following  report : 
The  Commission  has  collected  during  the  last  few  years  a  vast  amount  of  informa- 
tion, consisting  partly  of  facts  obtained  by  original  observations,  investigations  and 
compilations,  and  partly  of  opinions  and  experiences  obtained  from  a  large  number  of 
experts,  familiar  with  the  different  phases  of  the  problem. 

This  information  forms  a  storehouse  of  facts  and  opinions  pertaining  to  the 
largest  and  most  complex  sewage  disposal  problem  which  has  yet  required  a  solution. 

The  Commission  has  based  upon  this  extensive  information  general  plans  for  the  re- 
moval of  the  present  pollution  of  the  harbor  and  for  the  disposal  of  the  sewage  of  the 
Metropolis  extending  into  a  distant  future. 

I  have  read  your  comprehensive  reports,  have  examined  some  voluminous  matter 
.not  printed,  maps,  tables,  specimens  collected,  am  familiar  with  the  general  conditions 
as  a  long-time  resident  of  the  Metropolis,  and  have  recently  reinspected  certain  of  its 
localities  having  the  worst  polluted  waters. 

Introductory  Remarks 

As  a  preliminary  to  the  discussion  which  follows,  I  shall  briefly  state  the  main  con- 
ditions which  I  consider  are  the  foundation  of  the  problem  to  be  solved. 

The  Metropolitan  community,  at  present  estimated  to  contain  over  five  million 
persons,  resides  upon  about  700  square  miles  of  land  in  the  States  of  New  York  and 
New  Jersey,  bordering  the  Hudson  river,  the  East  river,  the  Kill  van  Kull,  the  Arthur 
Kill,  Newark  bay  and  the  Upper  and  Lower  New  York  bays.  The  water  areas  cover 
together  about  200  square  miles. 

The  entire  area,  now  populated  and  to  be  populated  in  the  future,  drains  into 


REPORT  OF  RUDOLPH  BERING 


221 


these  watercourses,  whether  it  is  the  natural  flow  from  the  rainfall  washing  its  sur- 
face or  the  artificial  flow  of  the  city  sewage  and  manufacturing  waste.  New  York  being 
the  largest  shipping  harbor  in  the  world,  there  is  added  to  the  discharge  of  this  dirty 
water  or  land  sewage  a  large  amount  of  ship  sewage,  which  also  contributes  to  the  pol- 
lution of  the  harbor  waters. 

Although  your  Commission  is  confined  by  law  to  the  consideration  of  the  condi- 
tions within  the  limits  of  the  State  of  New  York,  and  has  therefore  excluded  a  thor- 
ough investigation  of  the  conditions  within  the  limits  of  the  State  of  New  Jersey,  it 
must  be  evident  that  a  political  boundary  in  the  middle  of  a  river  or  a  bay,  both  shores 
of  which  are  densely  populated,  does  not  produce  a  sanitary  boundary,  so  far  as  the  pol- 
lutions of  the  water  and  of  the  stream  bed  are  concerned.  You  have,  therefore,  here  and 
there  extended  some  of  your  observations  across  the  State  line,  and  it  is  to  be  regretted 
that  the  same  thorough  examinations  as  have  been  made  on  the  New  York  side  could 
not  have  been  made  of  the  waters  and  shores  of  the  New  Jersey  side  of  the  rivers  and 
bays.* 

As  a  thoroughly  satisfactory  and  final  solution  of  the  sewage  disposal  problem  of 
the  Metropolitan  area  must  embrace  the  respective  populated  areas  within  both  States, 
and  as  the  solution  must  apply  to  their  polluted  waters,  and  should  accomplish  the  de- 
sired benefit  at  the  expense  of  both  States,  rated  in  fair  proportion,  the  conclusions  to 
be  reached  at  the  present  time  should  be  drawn  with  this  point  of  view,  and  in  the  fol- 
lowing discussions  this  broader  aspect  of  the  question  will  be  kept  in  mind,  so  far  as 
practicable. 

The  direct  discharge  of  all  of  the  filth  from  rain-water  washings  and  from  the 
city  and  ship  sewages  into  the  waters  of  the  Metropolis  has  caused  at  many  points  of 
the  harbor  quite  objectionable  conditions  to  sight  and  smell. 

a.  One  can  see  floating  upon  the  surface  of  the  water  over  extended  areas 
of  the  harbor  much  excretal  matter  discharged  by  the  sewers. 

b.  One  can  see  also  the  turbid  sewage  water  extending  into  the  river  quite 
a  distance  from  the  sewer  outlets. 

c.  Bubbles  of  gas  rising  to  the  water  surface  at  many  points,  some  of 
which  contain  malodorous  gases,  indicate  an  accumulation  of  putrefying  sewage 
sludge  deposits,  chiefly  at  sewage  outfalls  near  the  shores,  within  the  slips  and 
at  other  points  in  the  harbor. 

d.  Analysis  of  the  water  into  which  the  sewage  has  entered  indicates  sev- 
eral changes  from  the  original  composition  of  the  water,  the  most  significant  of 
which  for  the  present  purpose  is  the  reduction  of  oxygen,  which  is  usually 
found  to  saturate  normal  and  unpolluted  waters.  The  oxygen  dissolved  in  the 
water  acts  in  a  similar  manner  as  the  oxygen  contained  in  the  air,  by  converting 
lifeless  unstable  organic  matter  into  resistant  stable  inorganic  matter.  When 
organic  matter,  particularly  such  as  breaks  down  readily,  exhausts  the  avail- 
able oxygen,  or  cannot  withdraw  it  fast  enough  to  form  the  new  inorganic  com- 
binations, then  other  processes  of  decomposition  substitute  themselves. 

e.  In  the  presence  of  sufficient  oxygen  the  breaking-down  process  of  organic 
matter  is  inoffensive.  In  the  absence  of  sufficient  oxygen  the  process  can  be  either 
offensive  or  inoffensive.  It  is  offensive  when  the  resulting  malodorous  gases  in- 
clude chiefly  sulphur  compounds.    It  is  offensive  when  the  resulting  gases  are 

*This  is  an  error.  The  Commission's  investigations  were  by  law  required  to  cover  New  Jersey  as  well  as 
New  York,  and  the  existing  conditions  of  sewerage  and  sewage  disposal  are  fully  described  in  the  Com- 
mission's Report  of  April  30,  1910.  Ed. 


222 


REPORTS  OF  EXPERTS 


chiefly  marsh  gas  and  carbon  dioxide  and  exclude  the  malodorous  gases  by  proc- 
esses only  quite  recently  made  practicable. 

Lifeless  organic  matter,  such  as  we  find  in  seAvage,  can  therefore  be  decomposed, 
so  far  as  odorous  results  are  concerned,  by  offensive  and  inoffensive  processes.  Nat- 
urally all  efforts  to  dispose  of  the  Metropolitan  sewage  should  be  devoted,  as  far  as 
practicable  to  the  selection  of  those  processes  which  are  inoffensive. 

The  present  direct  discharge  of  sewage  into  the  waters  of  the  Metropolis  at  many 
points  not  only  causes  objectionable  conditions  as  to  sight  and  smell,  but  may  also 
cause  disease  germs  to  enter  these  waters  and  in  several  Avays  cause  subsequent  injury 
to  health.    Let  us  consider  also  these  objections  for  a  moment. 

a.  If  waters  are  to  be  used  for  drinking  there  can  be  no  question  but  that 
injury  could  result  to  the  health  of  the  consumer  from  any  sewage  discharge  as 
above  stated.  Such  waters  should  never  be  used  for  drinking  in  their  raw  state. 
Nor  Avould  such  waters  necessarily  be  safe  if  only  the  domestic  sewage  were  kept 
out,  still  leaving  to  enter  the  rain-water  washings  from  the  streets  of  a  large 
city  area,  the  overflow  from  sewers  in  times  of  storm  and  the  ship  washings  and 
waste  from  a  harbor.  All  such  street  wash,  seAver  overfloAvs  and  ship  seAvage 
expose  the  rivers  to  the  reception  of  pathogenic  bacteria  and  endanger  the 
health  of  those  imbibing  the  Avater.  As,  hoAveAer,  the  waters  surrounding  the 
New  York  Metropolis  are  brackish,  the  question  of  use  for  drinking  is,  of  course, 
excluded,  except  when  it  is  accidentally  SAvallowed  AAhile  bathing. 

b.  If  the  Avater  Avhich  receives  seAvage,  or  even  only  sewage  overflows  or 
street  Avashings,  is  used  for  bathing,  washing,  or  if  hands  should  be  Avet  by  it, 
it  is  possible  that  some  infection  might  be  transmitted.  While  direct  and  suffi- 
cient eA'idence  hereon  is  lacking,  it  is  reasonable  at  all  times  to  keep  this  point 
in  view  and  to  give  it  close  attention. 

c.  Pathogenic  bacteria  contained  in  seAA'ers,  such  as  cholera  vibrios  and 
typhoid  bacilli,  are  not  hardy.  When  floating  in  water  and  entirely  separated 
from  their  nutriment  they  soon  perish.  But  when  imbedded  Avithin  their  nutri- 
ment in  night  soil  or  sludge  they  have  lived  for  years.  No  proof  exists,  I  believe, 
that  if  taken  into  the  digestive  organs  of  fish  such  bacteria  have  infected  the  meat 
which  is  used  by  us  as  food.  Abundance  of  proof  exists,  however,  if  typhoid 
bacilli  are  drawn  within  the  shells  of  oysters  that  they  find  sufficient  nutriment 
therein  to  sustain  their  life  and  when  the  oysters  are  eaten  raw  they  have  caused 
the  consumer  to  contract  typhoid  fever. 

We  must  therefore  face  the  important  facts,  on  the  one  hand,  that  from  a  large  in- 
habited areas  pathogenic  bacteria  may  and  do  enter  the  adjoining  watercouses,  even 
should  the  largest  portion  of  the  seAvage  or  even  all  human  sewage  be  kept  out  of  them; 
and  on  the  other  hand,  that  they  may  be  taken  up  by  fish,  and  certainly  are  taken  up 
and  nutured  by  shell-fish  in  brackish  and  salt  water. 

There  is  no  practical  and  economical  way,  in  my  opinion,  to  prevent  all  pathogenic 
bacteria  from  entering  the  Metropolitan  waters.  Irrespective  of  sewage  overflows  and 
ship  sewage,  the  discharge  of  which  it  would  be  difficult  if  not  impossible  to  control,  it 
is  impracticable  to  entirely  exclude  the  rain  water,  which  washes  the  streets  and  yards, 
in  the  dust  of  which  are  deposited  all  kinds  of  bacteria  found  in  a  densely  populated 
city.  IIoav  far  it  will  be  economical  to  proceed  is  a  question  not  yet  definitely  deter- 
mined.   It  is  practicable  only  to  minimize  this  danger. 


REPORT  OF  RUDOLPH  HERING 


223 


To  minimize  the  objectionable  effects  of  rain-water  washings  and  sewer  overflows, 
the  most  efficient  means  are : 

First,  to  abolish  entirely  all  intercepting  sewers  from  overflowing  into  the  river. 

Second,  to  permit  at  suitable  and  numerous  points  the  first  rain-water  wash  from 
the  streets,  which  is  sometimes  as  foul  and  as  dangerous  as  ordinary  sewage,  to  enter 
into  intercepting  sewers  and  mingle  with  the  domestic  sewage  for  equal  treatment. 
The  wash  of  the  later  period  of  a  rainfall  could  be  left  to  enter  the  rivers  with  much 
greater  assurance  that  all  objectionable  matter  is  excluded  than  without  the  prior  in- 
terception. How  far  this  expedient  is  practical  must,  of  course,  be  determined  by  local 
studies. 

On  account  of  the  increasing  number  of  subways  in  Manhattan  extending  north 
and  south  and  interfering  with  the  combined  sewers  naturally  running  east  and  west, 
it  has  appeared  as  though  a  separate  or  double  system  might  become  economical  for  this 
part  of  the  Metropolis.  If  this  should  be  the  case,  and  if  the  domestic  sewage  of  Man- 
hattan or  a  part  of  it  would  have  to  be  subjected  to  some  treatment,  it  might  be  found 
practicable  to  add  to  this  sewage  also  the  first  wash  from  the  streets,  as  collected  by  the 
rain-water  drains. 

If  we  admit  the  impracticability,  as  I  do,  of  establishing  a  sewage  treatment  which 
excludes  from  the  Metropolitan  waters  positively  all  pathogenic  bacteria,  it  then  be- 
comes necessary  to  face  the  alternative  requirement,  namely,  to  protect  the  Metropoli- 
tan community  against  every  possible  danger  from  infection  through  whatever  bacteria 
will  still  enter  the  harbor.  The  following  restrictions,  therefore,  seem  to  me  to  be  in- 
evitable in  the  future. 

a.  Bathing  and  washing  may  be  prohibited  or  permitted  in  the  Metropoli- 
tan waters  only  within  respective  areas,  each  of  which  should  be  officially  deter- 
mined and  fixed. 

b.  No  fish  or  crabs  should  be  placed  on  sale  in  the  market  that  have  been 
taken  from  Metropolitan  waters  within  limits  officially  determined  and  fixed. 

c.  No  oysters,  clams  or  mussels  for  any  market  should  be  dredged  in  Met- 
ropolitan waters  within  limits  officially  determined  and  fixed. 

To  recapitulate,  the  Metropolitan  problem  of  sewage  disposal,  therefore,  embraces 
the  collection  of  the  sewage  in  a  manner  which,  so  far  as  practicable,  avoids  putrefac- 
tion within  the  sewers  and  is  delivered  at  points  where  it  can  be  given  a  final  disposal 
without  nuisance  of  any  kind  and  at  any  place,  and  which  will  prevent,  either  directly 
or  indirectly,  all  danger  to  health. 

The  collection  and  delivery  of  the  sewage  depends  upon  the  manner  in  which  it  is 
to  be  disposed  of  and  therefore  upon  the  points  where  it  is  to  be  delivered.  The  ways 
in  which  sewage  can  be  collected  and  delivered,  namely,  in  sewers  with  good  grades, 
smooth  interior  surfaces  with  no  opportunities  for  a  detention  of  the  sewage,  are  all 
well  known  and  need  no  further  remarks  except  that  in  this  respect  improvements  could 
be  made  in  the  different  boroughs  at  many  points.  The  new  problem  before  the  com- 
munity is  therefore  substantially  confined  to  that  of  the 

Final  Disposition  op  the  Metropolitan  Sewage 

A  final  disposition  should  be  made  without  causing  any  nuisance  or  any  danger 
to  health.  To  fulfil  the  latter  condition  it  was  stated  above  that,  on  account  of  not 
being  able  to  completely  prevent  all  pathogenic  bacteria  from  entering  the  Metropolitan 
waters  restrictions  should  be  placed  upon  the  use  of  such  waters  for  bathing  and  upon 


224 


REPORTS  OF  EXPERTS 


the  marketing  of  fish,  crabs,  oysters,  etc.,  taken  from  them  within  limits  to  be  estab- 
lished by  law.  Similar  restrictions  exist  in  the  cities  of  Germany  on  the  Rhine  and 
Elbe  and  in  English  cities  such  as  London. 

A  very  material  reduction  of  the  dangers  to  health  is  brought  about  by  the  circum- 
stance that  the  treatments  which  will  prevent  a  nuisance,  remove  also  the  pathogenic 
bacteria  which  may  attach  to  the  same,  leaving  but  a  very  small  proportion  which  may 
escape  death.  Therefore,  in  the  studies  made  by  the  Commission  chief  attention  was 
paid  to  the  means  of  preventing  a  nuisance. 

From  preliminary  conclusions  reached  above,  sewage  purification  may  be  accom- 
plished by  ways  and  means  which  are  offensive  and  inoffensive  and  all  present  efforts 
are  tending  to  apply  processes  which  belong  to  the  latter  class. 

Offensive  means  are  those  resulting  from  the  absence  of  oxygen,  together  with  the 
presence  chiefly  of  sulphur  bacteria.  So-called  septic  tanks  are  the  best  illustration  of 
the  offensive  process. 

Inoffensive  means  are  those  resulting  either  in  the  presence  of  oxygen,  or  when  this 
is  exhausted,  in  the  practical  absence  of  sulphur  bacteria.  In  the  following  only  the 
inoffensive  means  will  be  discussed. 

A.     DECOMPOSITION  BY  OXIDATION 

Dead  organic  matter  varies  from  being  very  resistant  to  being  non-resistant  to  de- 
composition. In  other  words,  it  may  vary  from  being  stable,  as  bones  or  hardwood,  to 
being  very  unstable,  as  blood  or  vegetable  juices.  The  resistant  condition  allows  of  a 
very  sIoav  decomposition  and  does  not  concern  us  here,  because  a  nuisance  does  not 
arise  thereby.  The  non-resistant  condition  rapidly  changes  the  constitution  of  the 
matter,  either  inorganically  or  by  the  action  of  bacteria,  which  seize  upon  the  oxygen 
in  contact  with  it  and  form  new  combinations  through  oxidation. 

Therefore,  the  exposure  of  unstable  dead  organic  matter  to  a  contact  with  oxygen 
in  sufficient  quantity  and  for  a  sufficiently  long  time,  effects  an  inoffensive  decomposi- 
tion which  can  be  obtained  either  in  air  or  in  water,  and  at  temperatures  suitable  for 
bacterial  activity. 

Oxidation  in  the  air,  i.  e.,  on  land,  is  obtained  when  the  sewage  is  spread  out  as  a 
thin  film  upon  a  firm  substance,  exposing  to  the  air  as  much  surface  as  practicable.  We 
have  then  the  most  favorable  relation  between  the  exposed  area  of  surface,  the  quantity 
of  air  available,  the  best  conditions  for  bacterial  activity  and  the  degree  of  purification 
accomplished.  Percolation  through  beds  of  sand  and  beds  of  coarse-grained  materials 
are  the  best  practical  means  of  securing  a  favorable  relation  for  oxidation  on  land,  as 
is  well  known. 

When  the  sewage  is  diluted  in  a  body  of  water  its  oxidation  is  obtained  by  a  thor- 
ough exposure  of  the  dissolved  and  finely  suspended  matter  to  the  oxygen  dissolved  in 
the  water.  Thorough  dispersion  in  a  sufficient  quantity  of  flowing  water  is  therefore 
the  practical  way  of  securing  it. 

As  the  quantity  of  dissolved  oxygen  available  in  the  water,  when  compared  with 
the  quantity  available  in  air,  is  not  as  large,  oxidation  in  water  is  not  as  rapid  as  oxida- 
tion on  land,  nor  can  the  same  result  be  accomplished  with  the  same  cubical  content  of 
medium  as  on  land.  On  the  other  hand,  oxidation  in  water  is  much  more  economical, 
because  it  does  not  require  extensive  special  works  nor  as  much  labor,  and  an  immediate 
dilution  in  sufficiently  oxygenized  water  at  once  stops  the  generation  of  odor. 


REPORT  OF  RUDOLPH   HERING  225 

In  order  to  secure  the  desired  oxidation  most  efficiently,  both  on  land  and  in  wa- 
ter, it  is  customary  to  limit  the  character  of  the  sewage  thus  to  be  treated  to  the  dis- 
solved and  fine  suspended  matter.  The  coarse  suspended  matter  is  therefore  generally 
first  removed  from  the  sewage. 

The  practicable  means  for  securing  the  oxidation  of  liquid  sewage  by  filtration  on 
land  are  so  well  known  that  for  given  requirements  and  conditions  of  the  New  York 
Metropolis,  the  necessary  areas,  capacities  and  costs  may  be  readily  ascertained.  We 
are  less  certain  regarding  the  best  means  of  separating  the  coarse  floating  and  heavy 
matters  from  the  dissolved  and  fine  suspended  matters  and  of  detaining  and  separately 
treating  them.    The  latter  subject  therefore  requires  a  few  remarks. 

Three  practicable  means  exist  and  are  used  to  obtain  such  separation.  One  is  a 
detention  by  screening,  another  by  floatage  and  a  third  by  deposition. 

Screening  is  limited  to  the  detention  of  suspended  and  floating  matter,  the  particles 
of  which  are  larger  than  the  openings  in  the  screen.  These  openings  vary  from  6 
inches,  holding  back  only  very  bulky  matter,  to  very  fine  slots,  the  finest  being  those  of 
the  screen  bearing  the  name  of  the  inventor  Riensch,  where  the  slots  are  but  one  mil- 
limeter wide.  Without  elaborating  this  subject  we  can  simply  conclude  from  the  ex- 
periences gained,  chiefly  in  Europe,  that  fine  screening  can  satisfactorily  detain  most  of 
the  suspended  and  floating  matter  objectionable  to  the  eye. 

Screening  with  Riensch  screens  is  the  only  treatment  given  in  Dresden.  Screens 
are  sufficient  also  in  Harrisburg,  where  they  have  openings  of  one  centimeter.  Still 
wider  openings  are  satisfactorily  used  in  screens  in  England,  where  the  seAvage  dis- 
charges into  estuaries. 

In  quite  a  number  of  European  cities  screening  is  the  only  treatment  given  the 
sewage  discharged  into  watercourses.  In  others  it  is  used  as  a  means  of  preliminary 
treatment  followed  by  some  process  of  oxidation. 

We  are  not  yet  agreed  upon  the  best  general  devices  for  screening,  nor  upon  details 
of  the  apparatus.  In  my  opinion  it  would  be  best  to  take  by  itself  each  case  in  the  Me- 
tropolis where  screens  are  to  be  used  and  from  among  the  several  well-tested  devices 
known  select  for  it  the  one  which  will  accomplish  what  is  desired  at  the  least  cost.  The 
heavy  storm- water  flow  in  our  combined  sewers  and  the  rise  and  fall  of  the  tide  in- 
crease the  difficulties. 

In  all  cases  of  screening,  even  where  the  finest  screens  are  used,  there  is  still  dis- 
charged with  the  sewage  a  large  amount  of  fine  suspended  matter.  The  amount  is 
usually  greater  in  weight  than  that  which  is  detained  by  the  screens.  The  passing  sew- 
age contains  also  the  larger  portion  of  the  non-resistant  organic  matter.  This  fine  mat- 
ter may  be  carried  in  suspension  until  it  is  deposited  as  sludge,  either  on  the  bottom 
or  at  the  shores  of  the  stream.  It  is  gradually  dissolved  and  decomposed  either  while 
suspended  in  the  water  or  after  deposit  as  sludge,  which  process  will  be  referred  to 
later. 

The  screenings  themselves  are  removed  periodically  by  hand  or  continuously  by 
machine  and  are  treated  more  or  less  successfully  in  various  ways  according  to  local 
conditions.  A  removal  of  the  moisture  by  pressure  to  reduce  the  bulk  for  handling, 
with  a  subsequent  burial  or  incineration,  is  the  most  usual  treatment  given.  If  the 
screenings  are  promptly  thus  disposed  of  when  fresh  no  nuisance  need  result. 

Another  means  of  securing  a  separation  of  the  solids  from  the  liquids  is  by  facili- 
tating the  fioataye  of  light  matter. 

When  the  velocity  of  a  moving  liquid  is  reduced  or  ceases  suspended  matter  lighter 


226 


REPORTS  OF  EXPERTS 


than  water  rises  to  the  surface  and  if  prevented  from  passing  on,  as  by  scum  boards 
and  end  walls,  it  will  accumulate  on  the  surface  and  can  be  periodically  removed  in 
bulk  by  hand,  or  continuously  by  machine,  as  in  the  case  of  screens. 

Floatage  collects  the  light  suspended  matter  by  passing  the  sewage  through  tanks 
or  detention  chambers,  of  larger  section  than  the  sewer,  to  reduce  the  average  velocity 
to,  say,  about  3  or  4  inches  per  second,  and  by  providing  a  submerged  outlet  at  the  bot- 
tom, the  discharge  pipe  from  which  leads  into  the  river. 

Floating  matter  is  thus  detained  at  the  surface  and  includes  also  some  fine  sus- 
pended matter  not  detained  by  screens,  the  amount  depending,  of  course,  upon  the 
velocity  with  which  the  sewage  passes  through  the  detention  chamber.  Matter  not 
rising  to  the  surface  will  not  be  retained,  but  will  enter  the  river.* 

In  order  to  prevent  any  deposit  of  heavy  matter  in  the  outfall  pipe,  a  grit  chamber 
is  placed  ahead  of  the  detention  chamber,  causing  a  velocity  of  not  much  over  nor  much 
less  than  12  inches  per  second. 

In  case  of  a  combined  system,  the  chamber  should  be  placed  to  one  side  of  the  sewer, 
so  as  to  allow  the  storm-water  flow  to  pass  as  before  to  the  river,  and  by  self-acting 
float  valves  be  prevented  from  entering  the  chamber.  The  water  level  and  floating 
matter  in  the  chamber  rises  and  falls  with  the  tide.  The  floating  matter  can  be  dis- 
posed of  by  burial  or  burning. 

A  third  means  of  securing  separation  of  solids  from  the  liquid  matter  is  through 
their  detention  by  deposition  in  settling  tanks  or  chambers.  These  tanks  allow  the 
heavier  materials  to  deposit,  the  floating  matter  to  be  retained  and  the  liquids  and  non- 
settling  fine  suspended  matter  to  pass  on. 

As  the  velocity  of  flowing  water  decreases  matter  held  in  suspension  by  its  move- 
ment begins  to  deposit.  The  well-known  curves,  showing  the  relation  of  velocity  and 
subsidence  of  sewage  matter  give  us  the  means  of  estimating  the  percentage  of  sus- 
pended matter  which  can  be  removed  by  subsidence  during  given  time  periods  of 
detention. 

The  mean  velocity  of  the  sewage  passing  through  such  tanks  has  varied  from  y2 
to  2  inches  per  second.  Experience  has  established  the  fact  for  European  sewage 
that  a  period  of  detention  of  one  to  two  hours  causes  a  deposit  of  all  matter  which  it 
is  found  economical  to  remove  by  this  means  and  to  be  treated  separately.  The  remain- 
ing suspended  matter  is  very  fine  and  it  is  found  that  practically  all  of  it  can  be  taken 
care  of  with  the  liquid  sewage  by  subsequent  oxidation. 

In  settling  tanks  it  is  natural  to  collect  also  the  floating  matter,  as  the  velocity  in 
them  is  small,  and  even  more  floating  matter  than  in  the  former  case  can  be  collected. 
Settling  tanks  must  be  much  larger  and  are  therefore  more  expensive  than  chambers 
designed  to  retain  only  floating  matter. 

If  sewage  is  delivered  to  the  point  of  deposition  in  a  fresh  condition,  which  can 
readily  be  done  by  sewers,  even  several  miles  in  length  when  these  are  properly  built 
and  kept  clean,  when  the  sewage  is  detained  not  longer  than  two  hours  to  deposit  its 
suspended  matter,  and  has  its  floating  matter  properly  removed,  no  offensive  conditions 
will  result,  if  reasonable  care  is  given  the  works. 


*The  term  "floatage"  is  probably  original  with  the  author.  It  does  not  appear  that  works  have  anywhere 
been  built  thus  far  to  carry  out  the  object  here  mentioned.  Ed. 


REPORT  OF  RUDOLPH  HERING 


227 


B.     DECOMPOSITION  IN  THE  ABSENCE  OF  SULPHUR  BACTERIA 

When  sewage  is  examined  quite  fresh  from  the  points  of  origin,  as  in  a  clean  house 
drain,  very  little  organic  matter  is  found  in  solution.  When  strained  through  filter 
paper  and  left  standing  it  rarely  becomes  foul.  As  the  sewage  continues  to  flow  in  the 
sewers  more  and  more  matter  is  dissolved  and  at  the  outfalls  in  many  cities  we  And 
about  one-half  of  the  organic  matter  to  be  in  solution. 

With  the  increasing  quantity  in  solution  bacterial  activity  also  increases  and  con- 
sumes the  oxygen  present  in  the  sewage  much  faster  than  it  can  be  reabsorbed  from  the 
air.    Eventually,  unless  prevented,  the  oxygen  is  all  consumed  and  putrefaction  begins. 

It  would  therefore  be  desirable,  where  it  is  practicable,  to  begin  treatment  by  an 
early  separation  of  the  solids  from  the  liquid  matter  and  in  any  case  well  before  the 
oxygen  dissolved  in  the  liquid  has  been  exhausted. 

The  treatment,  so  far  as  described  above,  is  first  a  separation  of  the  bulk  of  the 
solids,  either  by  screening,  floatage  or  sedimentation.  We  must  now  secondly  consider 
the  treatment  of  the  solid  material  which  has  been  deposited  in  settling  chambers  or 
tanks,  and  which  is  called  sludge. 

Until  within  a  few  years  the  treatment  of  domestic  sewage  sludge  invariably 
caused  an  offensive  decomposition  in  the  presence  of  sulphur  bacteria  when  collected 
in  plain  sedimentation  or  septic  tanks.  It  is  now  practicable  to  effect  the  deposition 
and  a  subsequent  more  rapid  decomposition  in  a  more  satisfactory  manner  without 
any  offensiveness ;  and  only  such  processes  should  here  be  considered. 

As  non-resistant  sewage  sludge  withdraws  oxygen  from  the  water  more  rapidly 
than  it  can  be  replenished  from  the  air  it  may  soon  become  exhausted.  The  conditions 
of  decomposition  then  change  and  new  classes  of  bacteria  become  active.  The  aerobic 
bacteria  cease  to  work  and  the  anaerobic  bacteria  develop  as  their  successors. 

Under  the  ordinary  conditions  when  oxygen  is  exhausted  we  find  that  some  of  the 
anaerobic  bacteria  produce  sulphureted  hydrogen  and  occasionally  other  foul  gases. 
Septic  tanks,  privy'vaults,  unclean  sewers  with  deposit,  extensive  sewage  deposits  in 
rivers  and  harbors  are  always  instances  of  foul  decomposition,  because  of  the  lack  of 
sufficient  oxygen  for  the  oxidation  of  the  non-resistant  organic  matter  present. 

It  has  lately  been  discovered  that  under  certain  simple  conditions  it  is  possible  to 
eliminate  the  bacteria  which  develop  sulphureted  hydrogen  and  to  restrict  the  an- 
aerobic bacteria  to  those  producing  chiefly  marsh  gas  and  carbon  dioxide,  neither  of 
which  gases  is  offensive. 

That  this  result  can  be  secured  under  all  ordinary  conditions  is  now  abundantly 
proven  in  practice  by  the  successfully  inoffensive  sludge  decomposition  in  over  130 
plants,  most  of  which  are  in  Germany.  The  plants  operate  equally  well  under  a 
variety  of  conditions,  dilute  and  strong  domestic  sewages  and  trade  sewages  from 
metal,  acid  and  alkali  works. 

The  essential  features  of  the  process  to  secure  this  result  and  as  developed  by  Dr. 
K.  Imhoff  are  as  follows: 

The  sewage  moves  through  a  chamber  in  which  it  is  detained  from  1  to  2  hours. 
During  this  time  from  90  per  cent,  to  100  per  cent,  of  the  settleable  suspended  matter 
deposits  upon  an  inclined  bottom  and  slips  through  a  slot  into  a  chamber  below.  The 
slot  is  so  arranged  that  no  gas  bubbles  resulting  from  decomposition  and  no  sludge 
particles  or  water  currents  can  rise  from  the  lower  into  the  upper  chamber,  to  mingle 
with  the  fresh  sewage,  but  instead  they  rise  through  a  special  shaft  directly  to  the  air. 

The  decomposition  of  the  accumulated  sludge  in  the  lower  chamber  gradually  as- 


228 


REPORTS  OF  EXPERTS 


sumes  .and  then  maintains  a  condition  in  which  the  classes  of  anaerobic  bacteria-pro- 
ducing offensive  gases  are  substantially  eliminated  and  only  those  remain  which  pro- 
duce about  75  per  cent,  of  marsh  gas  and  25  per  cent,  of  carbon  dioxide. 

After  the  sludge  decomposition  in  the  lower  chamber  has  become  fully  established 
there  is  not  only  an  absence  of  odor  from  the  escaping  gases  at  the  surface  or  from  the 
shafts,  but  also  an  absence  of  odor  of  the  sludge  itself,  both  while  it  is  decomposing 
and  after  the  process  is  complete.  The  absence  of  bacteria-producing  foul  smelling 
gases  is  therefore  evident. 

When  the  sludge  has  been  in  the  lower  chamber  some  3  to  6  months,  depending 
chiefly  upon  the  character  of  the  sludge  and  the  temperature,  and  has  been  kept  in  con- 
dition favorable  to  its  decomposition,  it  can  be  withdrawn  without  emitting  offensive 
odor,  as  the  non-resistant  matter  has  all  been  eliminated  by  the  decomposition. 

This  new  sludge  differs  from  the  usual  sludge,  and  especially  from  that  of  septic 
tanks,  by  its  absence  of  offensive  odor,  by  its  friability,  due  to  the  absence  of  non- 
resistant  slimy  and  sticky  matter  and  by  its  porosity,  due  to  the  expansion  of  the  gases 
of  decomposition  while  the  sludge  rises  from  the  bottom  of  the  lower  tank  to  the  sur- 
face of  the  ground.  These  qualities  allow  the  sludge  to  be  spread  out  over  sub-drained 
areas  and  dried  ready  for  removal  in  about  a  week.   It  then  resembles  garden  soil. 

Where  sufficient  area  for  this  drying  is  not  available,  the  sludge  can  be  withdrawn 
from  the  tanks  and  removed  either  on  land  or  water  to  points  of  final  disposition. 

Where  the  means  of  removing  the  sludge  from  the  sewage  by  sedimentation  is  im- 
practicable for  local  reason,  there  is  left  only  one  other  means,  namely,  letting  the  sedi- 
mentation take  place  as  at  present,  in  the  river  near  the  outlet  of  the  sewer.  This 
means  is  also  least  good  because  of  the  tendency  as  at  present  to  deteriorate  the  harbor 
water. 

In  this  case  the  sludge  must  be  removed  directly  from  the  river  bottom,  as  fre- 
quently as  practicable,  by  a  suction  dredge  placed  at  the  fore  end  of  a  barge,  with  or 
without  a  diver  handling  the  nozzle. 

For  the  removal  of  the  sludge  it  is  questionable  whether  it  will  be  cheaper  to  have 
barges  sufficient  in  number  and  large  enough  to  hold  and  remove  also  the  large  per- 
centage of  water  which  is  brought  up  with  the  sludge  or  to  separate  most  of  the  water 
from  the  sludge  by  a  centrifuge  and  discharge  it  through  a  separate  hose  hanging  down 
to  within  a  few  feet  of  the  river  bottom  from  the  rear  end  of  the  barge.  It  would  be 
necessary  to  discharge  this  water  near  the  bottom  on  account  of  its  being  offensive. 
The  frequency  of  such  a  removal  will  depend  upon  the  effect  which  the  deposited  sludge 
has  upon  the  harbor  water.  The  interval  between  the  removals  should  not  be  long 
enough  to  allow  effervescence  to  occur. 

When  the  sewage  is  allowed  to  pass  from  a  sewer  directly  into  the  river  a  screen 
must,  of  course,  always  be  provided,  and  also  a  grit  chamber  if  it  is  found  necessary. 

New  York  Harbor  Conditions 

1.   Investigations  Made  by  the  New  York  Metropolitan  Seiverage  Commission. 

The  Commission  has  made  a  very  extensive  and  systematic  study  of  the  New  York 
harbor  conditions.  It  has  collected  more  data  on  the  physical  and  social  conditions 
than  have  probably  been  collected  for  any  other  harbor. 

The  Metropolitan  area  investigated  is  over  700  square  miles.  A  large  number  of 
maps  have  been  prepared  indicating  almost  every  phase  of  the  problem.  Thousands 


REPORT  OF  RUDOLPH  HERING 


229 


of  bacterial  and  chemical  analyses  have  been  made  of  the  waters  at  all  depths,  at  all 
seasons  and  at  practically  all  important  points.  Over  100  experiments  were  made  with 
floating  objects,  to  show  the  movement  of  the  main  tidal  currents,  indicating  their  os- 
cillation and  the  slowness  with  which  the  polluted  harbor  water  gets  out  to  sea.  Be- 
sides these  investigations  innumerable  others  were  made  leading  up  to  the  designs  that 
have  been  proposed.  The  studies  included  almost  every  solution  of  the  problem  that 
might  be  suggested,  also  some  which  were  soon  eliminated  for  reasons  given. 

The  general  conclusion  reached  is  that  the  sewage  disposal  in  the  Metropolis 
should  be  radically  improved  in  several  directions,  and  the  suggested  improvements 
have  been  outlined  in  the  reports. 

2.  Currents  and  Tides. 

The  Commission,  in  connection  with  the  U.  S.  Coast  and  Geodetic  Survey,  has 
studied  the  currents  and  tides,  the  former  in  more  detail  than  has  been  done  before. 
It  found,  as  one  would  expect,  that  there  is  no  more  water  flowing  seaward  (tide  oscil- 
lation excluded)  than  the  land  water  which  enters  the  harbor,  and  that  a  large  part 
of  the  harbor  water  goes  into  the  Lower  bay  and  the  sound  with  every  ebb  tide.  The 
sea  water  returning  into  the  harbor  at  flood  tide  at  the  Narrows  and  Throgg's  Neck 
was  found  to  be  not  entirely  free  from  oxidizable  sewage  matter. 

The  Commission  further  found  that  water  of  the  East  river  between  the  Upper 
bay  and  Throgg's  Neck  simply  oscillates  within  this  stretch  most  of  the  time,  and  that 
the  diluting  Avater  is  received  at  both  ends. 

The  rising  and  falling  of  the  tide  averages  about  4.4  feet  at  Governors  Island. 
Tidal  and  land  water  have  different  limitations  in  quantity  of  discharge.  As  regards 
their  ability  to  flush  out  the  harbor  it  can  be  said  that  tidal  flushing  is  capable  of  keep- 
ing a  number  of  the  channels  free  from  deposit  and  sludge,  as,  for  instance,  a  large 
part  of  the  East  river.  Land  water  flushing  can  apply  to  the  Hudson  river  only  when 
this  is  in  flood.  In  floods  much  of  the  deposited  and  partly  decomposed  organic  matter 
may  be  picked  up  by  the  increased  velocity  of  the  water  and  carried  into  the  Lower 
bay  and  to  the  bar.  On  the  other  hand,  when  the  flood  recedes  much  of  the  partly  de- 
composed matter  brought  down  is  deposited  with  the  Metropolitan  sewage  in  the  bay. 
Therefore  I  do  not  consider  that  floods  in  the  Hudson  river,  so  far  as  sludge  removal  is 
concerned,  have  a  very  beneficial  effect,  except  by  temporarily  cleaning  the  river  bed  in 
some  locations  and  redepositing  sludge  in  others,  and  by  bringing  into  the  bay  fresh 
water  having  a  high  percentage  of  oxygen,  soon  to  be  lowered,  however,  to  the  present 
figures. 

3.  Sewage  Discharge. 

All  of  the  Metropolitan  sewage  with  little  exception  is  turned  into  the  Metropoli- 
tan tidal  waters.  Besides  the  floating  fecal  matter,  of  which  about  625  tons  are  dis- 
charged into  the  harbor  every  day,  making  the  surface  of  some  of  these  waters  un- 
sightly and  objectionable,  bacteria  can  be  found  in  the  water  almost  everywhere,  and 
about  16  tons  of  sludge  are  said  to  be  deposited  in  the  harbor  daily. 

To  fully  appreciate  the  relation  of  sewage  as  discharged  into  rivers  to  its  effect 
upon  the  river  water,  we  should  not  lose  sight  of  the  deception  likely  to  be  introduced 
by  the  designation  of  sewage  discharge  as  a  quantity  of  water  per  capita,  the  quantity 
of  water  depending  entirely  upon  the  water  supply  and  sub-soil  leakage  and  holding 
no  relation  to  amount  of  pollution. 

What  we  are  interested  in  is  the  organic  solid  and  liquid  sewage  matter  per  capita 


230 


REPORTS  OF  EXPERTS 


in  solution  and  in  suspension,  which  is  a  fairly  well  fixed  quantity.  The  water  supply 
gives  this  sewage  matter  its  first  dilution.  Sewage  of  American  cities  is  two  and 
three  times  as  dilute  as  the  sewage  of  European  cities,  but  we  have  no  more  sewage 
matter  per  capita  to  purify  than  they  have.  When  our  sewage  is  discharged  into  a 
river  it  is  already  much  more  diluted  than  European  sewage.  When  in  Europe  they 
require  30  dilutions  to  satisfy  the  demands  for  an  inoffensive  river  disposal,  we  in  this 
country  would  have  to  require  only  about  10  to  15  dilutions,  other  things  equal,  to 
accomplish  the  same  result. 

The  numerous  and  comprehensive  bacterial  analyses  made  by  the  Commission 
serve  as  a  good  index  of  the  conditions  of  the  water  in  the  harbor. 

Noteworthy  are  the  general  facts  that  the  largest  number  of  bacteria  are  near  the 
surface,  and,  with  very  few  exceptions,  the  smallest  number  is  near  the  bottom,  because 
the  oxygen  coming  from  the  air  is  most  readily  available  at  the  top.  And  again,  sew- 
age sludge  has  many  times  the  largest  number  of  bacteria,  although  mostly  of 'a  dif- 
ferent kind,  because  of  the  greater  quantity  of  decomposable  matter  present.  The 
greater  bacterial  activity  in  the  water  at  the  surface  than  near  the  bottom  perhaps  ex- 
plains the  fact  that  the  dissolved  oxygen  is  occasionally  found  to  be  slightly  less  at  the 
top  than  near  the  bottom. 

The  greater  the  number  of  bacteria  the  greater  is  the  pollution  by  dead  organic 
matter,  and  at  the  same  time  the  greater  is  the  effort  of  nature  to  mineralize  this  objec- 
tionable matter.  Generally,  therefore,  we  should  welcome  a  high  bacterial  content  in 
water  as  beneficial,  where  we  cannot  prevent  the  presence  of  dead  organic  matter  in  the 
water. 

Intestinal  bacteria  are  abundant  in  the  harbor,  but  only  a  few  kinds  are  patho- 
genic. Pathogenic  bacteria  are,  of  course,  very  objectionable,  but  fortunately,  when  en- 
tirely out  of  their  element,  they  soon  perish.  There  is  a  risk,  as  already  stated  else- 
where in  this  report,  when  pathogenic  bacteria  get  into  oysters  or  when  bathing  or 
handling  driftwood  permits  their  entrance  directly  or  indirectly  into  the  mouth. 

The  water  north  of  the  Narrows  is,  in  my  opinion,  unsuitable  for  the  cultivation 
of  shell-fish  at  any  point.  It  may  possibly  also  be  dangerous  to  bathe  in,  and  the  collec- 
tion of  driftwood  fuel  may  be  attended  by  some  risk  of  contracting  disease. 

For  the  further  purpose  of  this  discussion  let  us  again  consider  the  sewage  of  the 
Metropolis  in  its  three  parts :  That  which  floats,  that  which  settles  and  deposits  and 
that  which  remains  in  suspension  or  in  solution  and  is  carried  along  with  the  flowing 
water.   The  first  two  parts  will  be  mentioned  presently  and  the  last  one  now.* 

The  Commission  has  obtained  information  regarding  the  relation  of  the  incoming 
salt  water  to  the  outgoing  fresh  water  and  their  mixture,  and  regarding  the  increase  of 
salt  water  and  therefore  of  the  increase  of  coagulation  and  precipitation  of  the  organic 
matter.  It  is  also  known  that  plankton  perishes  and  deposits  to  a  larger  extent  in 
brackish  than  in  either  fresh  or  salt  waters. 

We  may  conclude  from  these  and  other  facts  that  in  New  York  harbor  as  in  other 
tidal  streams  there  is  a  greater  tendency  than  in  land  water  streams  to  precipitate  and 
deposit  solid  matter.  The  shoaling  of  all  coastal  streams  in  their  tidal  reaches  is  a 
well-known  fact. 

A  second  matter  of  importance  is  the  tendency  of  the  liquid  and  fine  suspended 
matter  of  sewage  to  become  thoroughly  dispersed  through  the  river  or  harbor  sections. 


•This  division  of  the  question,  and  in  fact  much  of  this  part  of  the  report  has  been  already  discussed  in 
the  Reports  of  the  Commission.  Ed. 


REPORT  OF  RUDOLPH  HERING 


231 


You  say  (Report,  August,  1912,  page  27),  particularly  with  reference  to  the  East 
river:  "The  configuration  of  the  shore  line  and  bottoms  and  the  velocity  of  the  tidal 
currents  all  combine  to  bring  about  a  thorough  intermixture  of  the  water."  And  again 
(page  34)  :  "It  appears  that  the  liquid  portion  of  the  sewage  which  is  now  discharged 
into  the  harbor  becomes  thoroughly  commingled  with  the  water  soon  after  it  loses  its 
identity  as  sewage.  After  it  has  once  become  mixed  with  a  few  times  its  bulk  it  becomes 
difficult  to  recognize  it  by  sight.   Marked  stratification  usually  does  not  long  persist." 

And  again  (page  32)  :  "The  sewage  which  is  discharged  into  the  waters  of  the 
Lower  East  river  is  soon  diffused.  Except  where  piers  and  slips  interfere  with  the 
normal  tidal  action,  the  mixing  effect  of  the  rapidly  moving  currents  is  clearly  appa- 
rent." To  indicate  the  occasional  diffusion  of  the  Hudson  river  water  throughout  the 
harbor  water  as  indicated  by  its  turbidity,  you  further  say :  "At  times  of  heavy  rain  the 
influence  of  the  Hudson  can  be  detected  by  the  turbidity  which  it  produces  through  the 
Upper  and  Lower  bays,  Kill  van  Kull  and  the  East  and  Harlem  rivers." 

You  also  say :  "The  presence  of  minute  particles  of  suspended  matter  well  dis- 
tributed through  the  volume  of  the  main  tidal  currents  is  in  itself  the  least  objectionable 
feature  connected  with  the  disposal  of  sewage  by  diffusion." 

The  percentage  of  dissolved  oxygen  is  fairly  uniform  throughout  the  cross-sections 
where  the  current  is  fairly  swift.  It  drops  down  near  the  shores  where  sewers  dis- 
charge, showing  that  its  effect  is  probably  soon  felt.  The  sewage  matters  in  the  harbor 
water  are  not  all  in  the  fresh  state,  but  in  various  stages  of  decomposition,  from  the 
early  carbon  fermentation  to  the  late  stages  of  nitrogen  fermentation. 

From  this  evidence  we  may  conclude,  if  sewage  is  discharged  into  the  current  in- 
stead of  at  the  shore  that  its  dispersion  throughout  the  mass  of  moving  water  is  greatly 
improved,  and  you  have  therefore  suggested  that  such  means  of  dispersion  should  be 
artificially  created  at  as  many  points  as  practicable. 

Regarding  the  detail  of  such  means  of  dispersion,  the  discharge  pipes  should  ex- 
tend laterally  across  the  current,  outlets  should  be  small  and  numerous  and  direct  the 
issuing  stream  as  nearly  horizontal  as  practicable,  so  that  the  dispersion  will  be  more 
rapid  and  complete  than  otherwise. 

Where  the  sewage  must  be  discharged  at  the  pier  head,  the  outlet  should  be  placed 
as  far  below  the  low  tide  level  as  practicable,  so  that  the  liquid  will  get  some  dispersion 
before  it  reaches  the  surface,  if  it  reaches  it  at  all.  The  designs  of  the  Commission 
have  been  made  with  consideration  of  these  practices. 

4.  Floating  Matter. 

The  suspended  sewage  matter  which  is  lighter  than,  and  therefore  floats  on  the 
surface  of,  the  harbor  water,  is  in  my  opinion  the  most  objectionable  aspect  of  the 
Metropolitan  sewage  question  at  the  present  time. 

It  was  apparent  as  a  nuisance  25  years  ago  and  as  such  it  has  since  been  materially 
increased  instead  of  reduced.  In  fact,  I  consider  it  to  have  been  the  chief  cause  for  the 
recent  popular  agitation  for  better  sewage  disposal  in  the  Metropolis.  With  the  floating 
matter  eliminated  most  of  the  present  offensive  conditions  of  the  harbor,  with  a  few  ex- 
ceptions, will  have  disappeared. 

Besides  the  625  tons  of  fecal  matter,  most  of  which  floats  about  for  a  while  in  large 
and  small  pieces,  there  is  also  much  vegetable  matter,  some  wood  and,  at  several  points, 
also  some  discoloring  trade  waste  to  defile  the  harbor  surface. 

Quite  a  lot  of  the  floating  debris  in  the  harbor  comes  from  the  docks  and  from 
ships,  which  an  enforcement  of  present  or  amended  ordinances  should  eliminate. 


232 


REPORTS  OP  EXPERTS 


Other  floating  material  is  oil  and  grease.  Unless  the  quantity  is  large  there  is  no 
offensive  odor  and  no  unhealthfulness  therefrom.  When  large  in  quantity  it  is  always 
an  objectionable  trade  waste  and  should  be  excluded  from  the  public  sewers  and  the 
harbor. 

The  odor  of  waste  oil,  particularly  from  gas  works,  sometimes  is  more  offensive 
than  that  of  fresh  domestic  sewage.  Such  waste  should  also  be  excluded  from  sewers 
and  from  rivers  and  from  harbors,  as  is  now  frequently  done  in  Europe.  When  the 
oily  film  or  sleek  is  confined  solely  to  that  which  naturally  comes  from  domestic  sewage 
it  is  very  slight  in  quantity  and  not  offensive  to  smell,  and  therefore  is  not  objection- 
able. 

Turbidity  of  the  river  and  harbor  waters  is  not  unhealthful  nor  does  it  necessarily 
constitute  a  nuisance.  Most  of  it  is  caused  by  heavy  rains  washing  the  soil  of  the 
drainage  areas,  and  it  is  not  practicable  to  prevent  it.  Nearly  all  of  our  southern 
rivers  are  almost  continuously  turbid.* 

To  prevent  the  objectionable  floating  matter  due  to  private  industries  and  ship- 
ping from  defiling  the  harbor  we  must  seek  the  remedy  first  at  the  sewers  and  sec- 
ondly by  carrying  out  the  police  regulations  against  harbor  pollution. 

At  the  sewers  we  can  operate  screens,  settling  tanks  or  floatage  chambers,  as  may 
be  found  most  efficient  at  the  specific  locality.  All  such  structures  require  careful  de- 
sign, but  also,  what  is  still  more  important,  efficient,  frequent  and  faithful  attendance, 
if  their  purpose  is  to  be  fulfilled.   They  are  frequently  used  in  Europe. 

The  drifting  of  floating  matter  suggested  the  systematic  use  of  suitable  floats  to 
indicate  the  points  to  which  sewage  would  flow  and  do  harm.  When  in  1882  a  large 
series  of  float  determinations  had  been  made  in  Providence  bay,  Rhode  Island,  I  found 
that  this  method  was  very  deceptive  for  such  a  purpose,  except  as  relating  to  large  and 
plainly  visible  floating  matter.  It  does  not  take  account  of  the  diluted,  dissolved  or 
dispersed  sewage,  which  may  not  be  recognized  at  all  as  sewage  when  it  reaches  a  shore, 
at  the  point  where  the  special  float  had  landed.  Nor  do  such  floats  take  account  of  the 
depositing  sludge.  Only  floats  used  to  determine  currents  give  reliable  information. 
Balls  placed  at  submerged  outfalls  may  also  lead  to  wrong  conclusions  regarding  the 
effect  of  sewage  discharge. 

Practical  and  economical  means,  to  more  or  less  prevent  the  nuisance  resulting 
from  large  quantities  of  floating  matter  in  the  harbor,  have  been  in  use  for  many  years 
in  other  places.  In  my  opinion  the  Commission  cannot  too  strongly  emphasize  the  rec- 
ommendations they  may  deem  proper  to  make  for  the  immediate  adoption  of  means  to 
prevent  floating  sewage  matter  from  appearing  anywhere  upon  the  surface  of  the 
harbor. 

5.  Sludge. 

The  suspended  sewage  matter  heavier  than  water,  and  therefore  settling  in  it,  is 
the  next  most  objectionable  part  of  fresh  raw  sewage  discharged  in  the  harbor,  because 
it  continuously  accumulates,  and  by  doing  so  withdraws  oxygen  as  rapidly  as  conditions 
will  permit.  After  the  oxygen  available  for  withdrawal  has  become  deficient  in  quan- 
tity, putrefactive  processes  are  started  in  the  sludge,  gas  bubbles  rise  to  the  surface  and 
carry  up  with  them  particles  of  a  putrescent  sludge  to  further  deplete  the  quantity  of 
dissolved  oxygen  which  is  being  reabsorbed  by  the  water. 

One  of  these  gases  is  sulphureted  hydrogen,  and  having  a  very  offensive  odor  is,  as 

•The  Commission  makes  a  distinction  between  turbidity  produced  from  the  washings  of  alluvial  land 
and  that  which  is  due  to  excessive  sewage  pollution.  Ed. 


REPORT  OP  RUDOLPH  HERING 


233 


we  know,  the  principal  cause  of  the  present  nuisance  objected  to  in  the  slips  and  docks 
of  the  harbor. 

Sludge  deposits  are  abundant  near  sewer  outfalls  in  the  slips  and  docks.  The 
worst  nuisances  are  from  Wallabout  and  Newtown  creeks,  in  the  Harlem  river  and  in 
and  from  Gowanus  canal,  because  in  all  these  cases  the  velocity  of  the  water  is  too 
slight  to  carry  all  of  the  suspended  matter  awaj'.  The  velocities  are  less  on  the  shallow 
than  on  the  deep  areas,  and  therefore  we  find  more  sludge  deposits  on  the  shoals  than 
in  the  channels  of  the  harbor.  The  Commission  has  found :  "That  practically  the  whole 
of  the  Upper  New  York  bay  and  the  Lower  Hudson  are  underlaid  by  an  accumulation 
of  foul-smelling  black  ooze." 

The  sludge  deposit  in  the  harbor  is  not  all  of  Metropolitan  sewage  origin.  In  fact, 
I  believe  only  a  small  part  of  it  was  ever  the  highly  putrescible  part  of  domestic  sew- 
age, which  is  the  first  to  be  oxidized  by  the  water.  As  before  stated,  much  organic 
matter,  chiefly  the  more  resistant  part,  is  brought  down  the  Hudson  and  deposited  in 
the  bays.  It  originated  by  the  discharge  into  the  river  of  the  rain-water  washings  from 
the  entire  drainage  area,  including  that  of  the  Metropolis.  Some  of  the  sludge  is  also 
due  to  the  accumulation  of  dead  plankton  in  the  brackish  waters.  The  non-resistant  or 
putrescible  matter  in  sewage  has  practically  disappeared  by  oxidation.  The  harbor's 
sludge  as  a  rule  is  not  very  non-resistant,  except  near  the  sewer  outfalls  and  in  the 
docks.  Some  distance  away  from  them,  but  not  near  shallow  shores,  it  is  in  the  last 
stages  of  decomposition,  and  no  more  putrefaction  is  noticeable  by  the  appearance  of 
any  effervescence  at  the  surface,  although,  of  course,  some  oxygen  absorption  is  still 
taking  place.  Near  the  sewer  outfalls  there  is  a  good  deal  of  non-resistant  sludge  de- 
posited, the  bacterial  activity  in  decomposing  it  and  the  resulting  oxygen  absorption 
is  much  greater  and  putrefaction  is  the  usual  final  result.* 

The  effects  from  putrefying  matter  are  much  more  objectionable  in  the  water  than 
are  the  effects  from  decomposing  fresh  matter.  The  former  not  only  imparts  an  offen- 
sive odor,  but  the  sulphides  formed  by  the  putrefactive  process  have  great  avidity  for 
oxygen,  and  by  direct  chemical  action  withdraw  it  from  the  water,  thus  assisting  its 
deoxidation  with  corresponding  rapidity. 

The  recent  Manhattan  practice  of  extending  the  sewers  to  the  pier  heads,  instead 
of  letting  them  discharge  into  the  docks,  has  improved  conditions  very  greatly,  but  the 
rising  tide  still  takes  some  of  the  suspended  sewage  particles  back  into  the  docks  and 
therefore  still  causes  some  deposit  due  to  the  slight  velocity  of  the  water  in  them. 

The  thicker  the  sludge  deposit  the  less  active  is  its  decomposition.  Where  the  de- 
posits have  accumulated  to  depths  of  over  3  feet  the  Commission  found  that  below 
this  depth  decomposition  practically  ceases,  partly  because  only  matter  remained  that 
had  been  rotted  out  and  partly  because  the  bacteria  perish  in  the  seclusion  by  the  poi- 
sonous effect  of  their  own  products. 

A  more  thorough  removal  of  the  sewage  sludge  than  heretofore  attempted  from  the 
rivers  and  bays,  both  at  present  and  hereafter,  will,  in  my  opinion,  very  effectively  bet- 
ter the  harbor  conditions,  not  only  by  preventing  its  putrefaction  in  the  river,  but  also 
by  increasing  the  dissolved  oxygen  content  of  the  water  and  therefore  improving  its  ap- 
pearance both  in  color  and  clearness. 

Dr.  Adeney  has  reported  to  you  (page  100  and  page  116  of  his  reportf),  and  I 

*This  is  in  error:  Many  thousand  cubic  yards  of  putrefying  sludge  were  removed  by  the  United  States 
Government  engineers  in  improving  Ambrose  channel,  in  lower  New  York  bay,  between  two  and  three  miles 
from  shore  and  seven  miles  from  any  large  sewer.    See  also  this  Commission's  Report  of  April  30,  1910.  Ed. 

fSee  Report  of  this  Commission  of  April  30,  1910.  Ed. 


234 


REPORTS  OF  EXPERTS 


strongly  support  his  opinion  from  extended  observations  both  in  Europe  and  America, 
that :  "There  can  be  no  doubt  that  the  waters  of  New  York  harbor  are  being  injuriously 
affected  by  the  sewage  solids  which  are  being  deposited  over  the  greater  portion  of  its 
bed."  "Of  all  the  constituents  of  sewage  the  solid  matters  in  suspension  cause  the  most 
injurious  results  in  tidal  waters."  "It  is  the  easily  and  directly  oxidizable  substances 
from  the  foul  deposits  that  now  cover  the  greater  portion  of  the  bed  of  the  harbor 
which  cause  the  large  deficiency  in  dissolved  oxygen  which  have  been  shown  to  obtain 
in  the  waters  of  the  harbor  by  the  investigation  of  the  Metropolitan  Commission." 

Opinions  have  been  expressed  that  the  sludge  has  a  less  important  effect  in  deoxy- 
genizing  water  than  that  imputed  by  Dr.  Adeney.  Relevant  experiments  have  been  re- 
cently made  and  a  verification  of  his  position  obtained  by  the  Commission. 

In  my  opinion  every  effort  should  be  made  to  keep  as  much  sewage  sludge  as  prac- 
ticable from  depositing  in  the  rivers  and  harbor  by  its  retention  on  shore.  I  believe 
that  at  least  the  worst  half  of  it  can  be  so  retained  in  tanks,  and  that  in  addition  a  good 
deal  can  be  removed  by  suction  dredges,  as  already  suggested. 

When  tanks  are  used  it  may  be  found  that  in  some  locations — later,  if  not  now — 
chemical  precipitation  or  rapid  filtration  may  be  advisable  to  increase  the  retention  of 
more  of  the  suspended  matter  than  will  deposit  in  plain  settling  basins. 

When  final  detailed  plans  are  made  the  special  character  of  works  for  the  most 
efficient  sludge  removal,  whether  Imhoff  tanks,  plain  settling  tanks  or  suction  dredges, 
should  be  determined  as  to  the  preference,  the  cost,  etc.,  for  every  outfall,  as  well  as  the 
best  method  of  finally  disposing  of  the  sludge  thus  collected. 

I  do  not  see  why  sewage  sludge,  either  at  the  shores  or  in  the  rivers,  being  objec- 
tionable at  least  as  a  nuisance,  should  not  be  collected,  removed  and  if  necessary  treated 
for  similar  reasons  to  those  which  cause  us  to  collect,  remove  and  sometimes  also  treat 
the  solid  refuse  of  city  streets.  Sewage  sludge  may  become  quite  as  objectionable  as 
does  night  soil  and  old  garbage,  and  to  let  it  putrefy  on  the  bed  of  a  river  is  a  relic  of 
olden  times  when  neither  knowledge  existed  as  to  how  to  deal  with  such  matters  nor 
money  was  available  to  pay  the  cost.  Keeping  the  river  beds  clean  in  front  of  our  cities 
is,  in  my  opinion,  just  as  desirable  as  keeping  our  streets  clean.  On  the  latter  we  see 
the  dirt,  on  the  river  bed  we  do  not  see  but  smell  the  effects  of  the  sludge.  Sludge 
exists  abundantly  in  our  harbors  and  it  affects  the  oxygen  of  the  water  flowing  over  it 
in  a  more  destructive  manner  than  the  street  dirt  affects  the  oxygen  of  the  city  air. 

I  believe  that  in  every  civilized  community  it  will  not  be  long  before  "river  clean- 
ing" will  be  deemed  as  desirable  as  "street  cleaning." 

(I.  Dissolved  Oxygen. 

The  best  practical  measure  of  the  degree  of  pollution  of  any  water,  to  determine  the 
amounts  of  unstable  dead  organic  matter  which  it  can  digest  without  causing  a  nui- 
sance and  the  amounts  which  probably  will  cause  a  nuisance,  is  the  quantity  of  free 
oxygen  dissolved  in  the  water.  Extensive  dissolved  oxygen  determinations  have,  there- 
fore, been  made  by  your  Commission  for  three  years,  covering  the  entire  water  terri- 
tory which  is  concerned  in  the  present  case.  With  this  information  you  have  studied 
the  digestive  capacity  of  the  harbor  and  have  concluded  that:  "It  will  not  be  necessary 
to  keep  all  the  sewage  out  of  the  harbor,  for  these  waters  can  absorb  a  large  amount  of 
sewage  harmlessly  and  inoffensively.  The  Commission  considers  that  this  capacity 
should  be  fully  utilized  and  has  undertaken  to  determine  to  what  extent  and  in  what 
ways  this  can  be  done." 

The  Commission  has  carefully  studied  the  effects  of  sewage  discharge  into  the  har- 


KEPORT  OF  RUDOLPH  BERING 


235 


bor  as  indicated  by  its  dissolved  oxygen.  All  the  observations  have  shown  a  tendency 
for  the  dissolved  oxygen  to  become  more  concentrated  near  the  surface  than  below, 
even  when  a  partial  depletion  exists  below.  Downward  streaming  and  evaporation  in- 
dicate the  manner  in  which  oxygen  is  replenished  in  the  water  below  the  surface  until 
it  reaches  the  sludge  at  the  bottom. 

Downward  streaming  is  caused  by  the  greater  weight  of  the  air-saturated  surface 
water,  which  may  finally  reach  the  bottom,  and  seems  to  be  the  chief  means  of  reoxidi- 
zing  the  layers  below.  Evaporation  in  sea  or  brackish  water,  due  to  the  solution  of 
sodium  chloride  and  other  salts  becoming  more  concentrated,  and  therefore  heavier  near 
the  surface,  also  causes  downward  vertical  currents. 

Water  flowing  in  an  irregular  channel,  with  changing  shores  and  river  bottom  fre- 
quently changes  its  course,  both  vertically  and  horizontally,  and  therefore  becomes 
more  or  less  thoroughly  mixed.  This  condition  exists  to  a  large  extent  in  the  New  York 
harbor,  and  particularly  in  the  East  river,  as  the  Commission  has  shown. 

The  result  of  this  constant  intermixture  is  advantageous  also  in  the  fact  that  it 
facilitates  a  greater  oxygen  absorption  at  the  surface.  As  a  rule  there  is  not  a  great 
difference  between  the  resulting  amount  of  oxygen  in  the  surface  and  in  the  bottom 
layers,  probably  because  of  the  greater  bacterial  activity  near  the  surface. 

The  depletion  of  oxygen  has  taken  place  pretty  generally  throughout  the  entire 
harbor,  but  to  different  degrees  in  different  parts,  as  shown  by  your  plottings.  This 
depletion  has  been  caused  partly  by  the  dissolved  and  light  suspended  organic  matter 
which  enters  the  harbor  chiefly  from  the  sewers  and  partly  by  the  deposits  of  sludge. 
Where  the  sewage  discharge  and  sludge  deposits  are  greatest  the  dissolved  oxygen  is 
lowest. 

The  East  river  is  the  most  depleted  part  of  the  harbor,  it  receives  the  largest 
amount  of  sewage  and  has  the  least  favorable  opportunity  of  having  its  water  thor- 
oughly changed  and  replaced  by  oxygen-saturated  water. 

At  Pier  10  and  at  the  Brooklyn  Bridge  the  degree  of  saturation  in  July  and  Au- 
gust, 1913,  when  it  was  lowest,  fell  to  figures  varying  from  13  to  25  per  cent.  Else- 
where the  figures  are  materially  higher. 

In  general  it  may  again  be  said  that  sewage  cannot  be  as  rapidly  purified  in  water 
as  in  air,  because  of  the  comparatively  small  amount  of  oxygen  that  is  dissolved  in 
water,  and  because  of  the  less  good  opportunity  there  is  for  contact  between  sewage 
matter  and  oxygen,  as  compared  with  filters.  Consequently  oxidation  in  water  requires 
a  longer  time. 

As  regards  the  effect  of  a  depletion  of  oxygen  in  the  water  upon  fish  life,  it  may 
be  said  that  for  major  fish  the  figure  70  per  cent,  has  been  recommended  for  New  York 
harbor.  While  it  is  desirable  to  keep  water  for  major  fish  life  as  highly  aerated  as  pos- 
sible, we  know  that  such  fish  have  not  always  been  destroyed  even  by  a  very  much 
lower  figure.  In  the  Potomac  below  Washington  there  is  good  fishing  with  oxygen  oc- 
casionally at  50  per  cent,  saturation.  The  amount  of  oxygen  to  be  maintained  in  water 
is  mainly  a  question  of  preference  between  the  financial  value  of  the  fish,  which  may 
not  be  able  to  live  in  waters  used  for  sewage  oxidation  and  the  cost  of  preventing  the 
deoxidation. 

If  it  were  desirable  to  permit  fish  to  ascend  a  large  stream  for  spawning,  as,  for 
instance,  the  Hudson,  it  would  not  be  necessary,  in  my  opinion,  to  require  sufficient 
oxygen  in  all  of  the  rest  of  the  harbor  water,  but  only  in  those  waters  directly  connect- 


236 


REPORTS  OF  EXPERTS 


ing  the  Hudson  with  the  ocean.  It  would  not  be  necessary  throughout  the  East  river, 
as  the  fish  in  the  sound  might  go  elsewhere  than  up  the  Hudson  for  spawning. 

Dunbar  says:  "It  is  the  sulphur  forming  foul-smelling  sulphureted  hydrogen 
which  is  strongly  poisonous  to  fish  life."  The  result  of  putrefaction  is  more  injurious 
to  fish  life  than,  within  limits,  a  mere  scarcity  of  oxygen.  Therefore,  by  preventing  the 
putrefaction  of  sludge  deposits  and  the  consequent  escape  into  the  water  of  foul  gases 
resulting  therefrom,  by  the  interception  of  sludge  on  land,  or  by  frequently  removing  it 
with  suction  dredges  from  the  river  bottom,  putrefaction  can  be  minimized  and  the  de- 
gree of  dissolved  oxygen  increased  in  the  harbor  water  for  the  benefit  of  fish  life. 

It  is  my  opinion  that  the  question  of  major  fish  life  in  New  York  harbor  should  not 
take  the  first  place  in  a  consideration  involving  so  large  an  expenditure  as  would  be 
necessary  for  the  final  disposal  of  the  Metropolitan  sewage.  However,  so  far  as  the  de- 
gree of  dissolved  oxygen  affects  the  health  of  the  population  and  affects  the  question 
of  a  possible  nuisance  to  this  population,  it  must  be  seriously  taken  into  account.  I 
shall  refer  to  this  subject  again  later. 

The  source  of  the  dissolved  oxygen  is  river  and  harbor  waters  is  the  atmosphere 
from  which  it  is  absorbed.  The  harbor  waters  receive  oxygen  from  the  Hudson,  the 
Passaic  (in  the  future)  and  the  Hackensack  rivers,  from  the  flood  tides  entering  the 
harbor  at  Throgg's  Neck  and  at  the  Narrows  and  from  absorption  at  the  surface  of  the 
harbor  waters.   We  may  call  the  area  of  the  harbor  waters  about  60  square  miles. 

Practically  all  of  the  Metropolitan  sewage  is  now  discharged  into  the  harbor,  and 
it  also  practically  disappears  within  its  area.  The  disappearance  is  brought  about 
partly  by  subsidence  and  decomposition  of  the  resulting  sludge  and  partly  by  oxida- 
tion of  the  liquid  and  fine  suspended  sewage  within  the  harbor. 

Ebb  tide  takes  some  of  the  unoxidized  sewage  out  to  sea  beyond  Throgg's  Neck  and 
the  Narrows.  Most  of  the  flood  tide,  however,  brings  back  almost  completely  oxygen- 
ated water. 

If  the  surface  of  the  water  is  kept  fairly  well  broken  the  reaeration  readily  pro- 
ceeds. When  the  quantity  of  dissolved  oxygeu  is  insufficient  to  oxidize  the  sewage,  the 
sewage  and  sludge  together  may  in  an  extreme  case  produce  black,  putrid  and  foul- 
smelling  water,  with  bubbles  of  odorous  gases  arising  from  the  sludge. 

Sludge  draws  oxygen  from  the  water  with  greater  avidity  than  sewage  in  solution, 
but  dissolved  matter,  on  the  other  hand,  decomposes  in  the  presence  of  sufficient  oxy- 
gen far  more  rapidly.  The  reaeration  of  sea  water  proceeds  more  rapidly  than  the 
reaeration  of  land  water.  The  favorable  configuration  of  the  harbor,  of  land  and  sea 
water  entrances  aiding  the  intermingling  of  the  waters  by  the  tides  and  currents,  the 
oscillation  due  to  the  tides  and  the  effect  of  the  shipping  and  winds  all  contribute  to 
getting  a  good  mixture  of  sea  and  land  water  and  of  the  top  and  bottom  waters,  the 
result  of  which  is  shown  in  the  fairly  uniform  distribution  of  the  dissolved  oxygen  in 
most  parts  of  the  harbor. 

We  have  various  estimates  as  to  the  amount  of  dissolved  oxygen  necessary  to  oxi- 
dize the  screened  and  settled  sewage  per  second  per  capita,  such  as  0.80  mg.  in  Chicago, 
0.35  mg.  in  Hamburg  and  0.22  mg.  in  Frankfort,  etc. 

If  we  roughly  assume  the  figure  for  New  York  at  0.50  mg.  per  capita  per  second 
we  would  require  for  a  population  of,  say  6,000,000  people,  as  much  as  3,000  grams  of 
oxygen  per  second,  or  260,000,000  grams  per  day. 

Dibdin  concludes  from  some  of  his  observations  that  all  the  organic  matter  in  sew- 
age will  be  completely  oxidized  by  from  one  to  three  times  its  weight  of  oxygen.  The 


REPORT  OF  RUDOLPH  HERING 


237 


total  organic  and  volatile  matter  in  sewage,  averaged  from  several  authors,  is  about  77 
grams  per  capita  per  day.  We  should,  therefore,  require,  according  to  Dibdin,  for 
6,000,000  persons  from  462,000,000  to  1,386,000,000  grams  per  day  to  oxidize  the  sewage. 

If  we  realize  that  Dibdin's  figures  are  for  getting  complete  oxidized  organic  matter 
from  crude  sewage  and  the  others  are  for  getting  non-putrescible  matter  from  settled 
or  screened  sewage,  removing  a  large  part  of  the  solid  matter,  they  will  reasonably  com- 
pare with  those  above  assumed.  More  definite  information  on  this  subject  is  necessary 
and  will  no  doubt  be  forthcoming  in  the  future.  I  understand  that  the  Commission  has 
obtained  some. 

The  oxygen  required  is  partly  absorbed  from  the  air  at  the  surface  of  the  harbor 
and  partly  brought  into  the  harbor  with  the  flow  of  the  Hudson  and  with  the  flood  tides 
from  the  sound  and  the  ocean.    The  other  sources  are  negligible. 

The  ordinary  minimum  flow  of  the  Hudson  river  is  1,500,000,000  gallons  per  day. 
Let  us  assume  that  about  one-third  of  its  dissolved  oxygen  is  available  for  the  oxidation 
of  the  Metropolitan  sewage,  say  3  milligrams  per  liter,  or  12  milligrams  per  gallon. 
Then  the  daily  amount  of  dissolved  oxygen  available  from  the  Hudson  river  is  IS, 000 
kilograms.  The  aerated  tidal  waters  entering  Xew  York  bav  twice  a  dav  from  the 
ocean  and  the  sound,  let  us  assume  to  be  roughly  200,000,000,000  gallons  per  day,  and 
let  us  further  assume  that  the  available  amount  of  oxygen  in  it  for  oxidizing  the  Metro- 
politan sewage  is  only  5  milligrams  per  gallon.  The  daily  amount  of  oxygen  available 
from  the  ocean  waters  may,  therefore,  be  1,000,000  kilograms. 

The  surface  of  the  harbor,  where  practically  all  of  the  sewage  is  discharged, 
namely,  about  60  square  miles,  equals  say  1,672,000,000  square  feet.  If  we  take 
Adeney's  figures  of  oxygen  absorption  of  half  sea  to  half  land  water  at  0.055  c.c.  per 
liter  per  hour,  equaling  0.000078  gram  per  liter  per  hour,  and  assume  that  atmospheric 
oxygen  penetrates  the  fairly  rough  harbor  surface  about  one  inch  in  one  hour — a  safe 
minimum — then  0.000175  gram  would  be  absorbed  per  hour  per  square  foot,  or  292,700 
grams  per  hour  from  the  entire  harbor  surface,  or  about  7,000  kilograms  per  day. 

We  may  then  estimate  the  available  oxygen  for  sewage  oxidation  in  the  New  York 
harbor  water  quite  roughly  as  follows : 

Hudson  river   18,000  kilograms  per  day 

Sea  water   1,200,000         "        "  " 

In  the  Bay  and  East  river   7,000         "        "  " 

1,225,000         "         "  " 

It  appears  that  the  sea  water  brought  into  the  harbor  practically  furnishes  the 
bulk  of  the  oxygen  for  decomposing  the  Metropolitan  sewage. 

We  found  that  6,000,000  people  required  about  260,000  kilograms  of  oxygen  per 
day  to  decompose  their  sewage  after  it  had  been  screened  and  settled.  We  also  found 
that  Dibdin's  estimate  of  the  amount  of  oxygen  required  to  completely  mineralize  the 
entire  organic  matter  of  raw  sewage  ranged  from  462,000  kilograms  to  1,386,000  kilo- 
grams. These  figures  I  think  safely  indicate  that  if  floating  and  visible  suspended  mat- 
ter is  removed,  if  sludge  accumulation  in  the  harbor  is  prevented  and  if  the  sewage  is 
thoroughly  dispersed  in  the  harbor  waters  the  remainder  of  the  sewage  can  be  oxidized 
by  the  sea  waters  to  a  degree  which  would  not  produce  objectionable  conditions  for 
years  to  come. 

Adeney  in  his  report  to  your  Commission  supports  the  same  opinion  when  he  says 
that:  "The  harbor  waters  are  quite  capable  of  satisfactorily  disposing  of  the  liquid 


238 


REPORTS  OF  EXPERTS 


sewage  matter  from  Greater  New  York  for  many  years  to  come,  provided  the  solid 
matter  be  first  removed." 

The  above  figures  are,  of  course,  not  sufficiently  exact  to  show  how  long  this  dilu- 
tion will  suffice  for  the  rapidly  growing  Metropolis.  The  present  time,  however,  is  not 
too  early  to  get  closer  and  more  exact  figures  and  to  ascertain  what  should  be  the  ulti- 
mate remedies  which  must  be  applied,  after  the  floating  matter  and  sludge  removals 
have  been  accomplished  to  the  greatest  practicable  extent,  and  the  Commission,  in  my 
opinion,  has  wisely  considered  a  number  of  such  further  solutions. 

Experiences  Elsewhere 

There  are  several  large  cities  where  sewage  has  been  discharged,  untreated  or 
nearly  so,  into  watercourses  of  brackish  or  fresh  water.  The  experience  there  gained 
is,  in  my  opinion,  a  more  trustworthy  guide  in  forming  an  opinion  regarding  the  con- 
ditions to  be  expected  in  New  York  than  any  laboratory  work,  or  calculations,  as 
above.  I  may  mention  London,  Hamburg,  Washington  and  Philadelphia.  The  Com- 
mission is  acquainted  with  most  of  the  details  of  these  cases,  but  I  shall  repeat  a  few 
general  facts  and  add  a  few  more. 

London.  The  Thames,  with  a  tidal  range  of  18  feet,  receives  the  sewage  from  a 
larger  population  than  New  York,  and  its  condition  indicates  that  brackish  water  of  a 
tidal  stream  can  remain  in  a  satisfactory  state  with  an  oxygen  content  of  only  25  per 
cent,  of  saturation.  I  understand  it  has  fallen  to  5  per  cent,  without  causing  a  nui- 
sance. I  have  been  on  the  Thames  on  several  occasions  of  low  dissolved  oxygen  and 
have  not  noticed  the  slightest  offense.*  The  sewage  is  relieved,  before  discharging,  of 
about  half  of  its  suspended  matter,  and  sludge  is  continually  being  dredged  from  the 
river,  this  material  being  mostly  due  to  the  accumulation  of  rain-water  washings  rather 
than  to  sewage.  Mr.  Fitzmaurice  and  Mr.  Clowes  report  this  disposal  as  being  quite 
satisfactory. 

Besides  keeping  out  the  floating  matter  the  only  treatment  given  since  about  1891 
is  precipitation  at  Barking  and  Crossness.  Of  late  Mr.  Fitzmaurice  has  expressed  the 
opinion  that  plain  subsidence  without  chemicals  might  yet  be  sufficient  to  prevent  nui- 
sance in  the  Thames  for  a  number  of  years.  A  removal  of  the  suspended  matter  to  as 
large  a  degree  as  practicable  and  a  dissolved  oxygen  content  frequently  of  20  per  cent, 
has  been  found  quite  satisfactory. 

Hamburg.  In  Hamburg  the  river  Elbe  lias  a  tidal  range  of  about  6  feet  and  con- 
tains only  land  water  from  which  about  one-half  of  the  city's  water  supply  is  obtained 
at  the  upper  end  of  the  city.  Only  floating  matter,  grit  and  an  almost  insignificant 
amount  of  sludge  is  intercepted  and  removed  to  outside  of  the  city.  The  sewage  from 
about  1,000,000  people  enters  the  Elbe  within  the  harbor  a  few  hundred  feet  from  shore 
and  discharges  at  the  bottom  of  the  river  from  several  outlets.  The  annual  typhoid 
fever  rate  is  only  4  per  100,000.  The  conditions  for  sewage  oxidation  are  less  favorable 
than  in  New  York.  The  water  area  is  much  less  and  the  shipping  per  square  mile 
greater.  There  is  no  floating  sewage  on  the  river  and  no  sludge,  as  the  deposit  is  fre- 
quently dredged. f  In  the  season  of  low  water,  i.  c,  in  the  late  summer,  the  dissolved 
oxygen  has  dropped  to  40  per  cent.,  and  still  lower,  without  causing  the  harbor  waters 
to  be  objectionable.   The  water  supply  of  Altona,  a  city  of  about  180,000  inhabitants,  is 

•This  is  contrary  to  official  statements  which  indicate  that  odors  from  the  sewage  are  noticeable  for  about 
twelve  miles  above  and  below  the  outfalls,  although  not  of  sufficient  strength  to  be  objectionable  beyond  the 
river's  banks.  Ed. 

fMuch  of  the  sewage  rises  to  the  surface  and  the  solid  matters  are  eagerly  sought  by  seagulls.  Ed. 


REPORT  OF  RUDOLPH  HERING 


239 


taken  from  the  Elbe,  about  7  miles  below  Hamburg,  and  with  double  filtration  has  been 
entirely  satisfactory  at  all  times. 

Washington.  The  sewage  of  Washington  in  its  raw  condition  is  continuously  dis- 
charged into  the  channel  of  the  Potomac  river  by  two  outlets  100  feet  apart  and  about 
27  feet  below  low  tide.  The  river  is  a  tidal  stream  with  a  range  of  about  18  inches  and 
no  sea  water  ascends  to  the  city.  The  flow  of  the  river  varies  from  2,000  to  40,000  cubic 
feet  per  second  and  during  the  lowest  flow  the  water  oscillates  during  the  tide  about 
12,000  feet.  The  dilution  has  varied  from  1  part  sewage  and  45  parts  river  water  in 
October,  1912,  to  1  part  sewage  and  234  parts  river  water  in  March,  1913.  For  the 
minimum  flow  of  the  river,  which  is  about  2,000  cubic  feet  per  second,  and  for  the  pres- 
ent population  of  about  350,000  there  is  a  land  water  flow  of  5.7  cubic  feet  per  second 
per  1,000  persons. 

I  have  seen  the  surface  of  the  Potomac  river  both  when  it  was  calm  and  rough, 
and  no  objectionable  conditions  were  apparent  at  either  time.  The  minimum  monthly 
per  cent,  of  saturation  with  oxygen  near  the  outfall  was  50  per  cent,  for  a  flow  of  4,505 
cubic  feet  per  second  during  August,  1912.  The  monthly  dissolved  oxygen  figure 
ranged  from  70  per  cent,  in  September  to  96  per  cent,  in  February. 

All  floating  bulky  and  heavy  matter,  including  substantially  all  grease,  is  automat- 
ically held  back  at  the  shore,  when  passing  through  a  grit  chamber,  screens  and  skim- 
ming tank.  The  outfall  pipes  descend  to  the  river  bottom  and  extend  to  the  outlets 
above  mentioned.  Examination  of  the  river  bottom  and  beaches  show  no  evidence  of 
sludge  or  deposits  and  the  surface  of  the  river  is  substantially  free  from  oil  and  sleek. 
The  fishing  grounds  in  the  vicinity  are  called  excellent.* 

My  purpose  in  calling  attention  to  the  Washington  case  is  to  show  the  benefits 
from  the  removal  of  floating  matter  and  of  discharging  and  dispersing  the  sewage  at 
the  bottom  of  the  channel.  The  dissolved  oxygen  is  amply  sufficient  to  decompose  the 
discharged  sewage. 

Philadelphia.  Studies  have  recently  been  made  of  the  Delaware  and  Schuylkill 
rivers  by  the  Bureau  of  Surveys  under  the  direction  of  Mr.  George  S.  Webster,  Chief 
Engineer  and  Surveyor,  with  reference  to  the  effects  of  discharging  into  them  the  raw 
sewage  of  the  City  of  Philadelphia  from  many  outlets  along  the  shores.  A  report  on  the 
results  will  soon  be  issued  and  the  conclusions  drawn  from  them  will  be  interesting.! 
They  will  also  facilitate  a  better  comprehension  of  some  of  the  New  York  conditions. 

Both  rivers  are  tidal  streams,  the  range  being  about  5  feet.  The  normal  land  water 
flow  of  the  Delaware  river  is  4,050  cubic  feet  per  second;  the  minimum  flow  is  2,030 
cubic  feet  per  second.  The  normal  Schuylkill  river  is  1,270  cubic  feet  per  second,  and 
the  minimum  is  zero  below  the  Fairmount  dam.  The  population  of  Philadelphia  is 
about  1,600,000,  of  which  450,000  dwell  upon  the  watershed  of  the  Schuylkill  river  and 
1,150,000  dwell  upon  the  watershed  of  the  Delaware  river.  Upon  the  watersheds  of  both 
rivers,  within  10  miles  of  the  City  of  Philadelphia,  there  dwell  approximately  2,000,000 
people. 

The  Schuylkill  river,  below  Fairmount  dam,  has  much  of  the  time  either  slack 
water  or  a  very  slight  velocity.  Therefore  its  bed  is  pretty  generally  covered  with 
sludge,  near  its  mouth  to  a  depth  of  several  feet.  Most  of  it  is  in  a  state  of  active  putre- 
faction, even  in  cold  weather.   The  river  water  in  the  lower  reaches  consequently  con- 

*It  should  be  noted  that  the  Washington  sewage  is  extremely  weak,  and  that  the  Potomac  is  a  muddy 
stream  and  subject  to  freshets. 

fExtensive  improvements  in  the  disposal  of  the  City's  sewage  will  be  proposed  in  this  report.  Ed. 


240 


REPORTS  OP  EXPERTS 


tains  very  little,  if  any,  dissolved  oxygen,  and  practically  none  during  all  the  summer 
months.  It  is  exhausted  faster  than  it  can  be  replenished  from  the  surface.  The  condi- 
tion of  the  river  has  been  foul  and  objectionable  for  many  years. 

The  Delaware  river  has  a  good  current  and  forms  the  chief  part  of  the  harbor. 
The  bottom  is  consequently  generally  clean,  except  where,  on  account  of  sewer  outlets 
and  a  reduction  of  the  velocity  in  the  docks,  sludge  has  accumulated  and  is  mostly  in  a 
putrefying  condition. 

The  greater  part  of  the  water  supply  of  Philadelphia  is  taken  from  the  Delaware 
river  at  Torresdale,  about  10  miles  above  the  center  of  the  city's  sewage  discharge. 
The  water  is  filtered  and  the  death  rate  from  water-borne  diseases  is  very  low.  During 
flood  tide  some  of  the  city  sewage  is  taken  upon  the  river  beyond  the  water  intake,  as 
indicated  by  the  depletion  of  dissolved  oxygen  in  the  river  opposite  the  intake,  which 
depletion  has  been  as  low  as  50  per  cent,  under  extreme  conditions  of  high  tide  and 
drought  in  the  late  summer. 

As  the  water  flows  down  the  river  from  this  point  it  receives  the  sewage  of  the 
city  from  one  outlet  after  another.  Both  the  sewage  and  the  deposited  sludge  in  the 
docks  continuously  extract  oxygen  from  the  water.  Although  there  is  constantly  also 
a  fresh  absorption  of  oxygen  at  the  surface,  the  depletion  during  the  summer  of  1912 
was  greater  than  the  absorption,  so  that  opposite  the  center  of  the  city  (Arch  Street), 
about  500  feet  from  shore,  the  dissolved  oxygen  was  reduced  to  an  average  of  less  than 
20  per  cent,  between  July  1  and  September  20,  1912,  and  yet  during  this  time  there  was 
no  odor  whatever  at  such  localities  in  the  Delaware  river. 

Below  the  mouth  of  the  Schuylkill  river  no  more  Philadelphia  sewage  enters  the 
Delaware  river,  and  as  the  water  flows  down  stream  the  dissolved  oxygen  increases 
from  about  30  per  cent,  to  60  per  cent,  in  seven  miles ;  which  indicates  that  the  absorp- 
tion from  the  air  at  the  surface  of  the  river  is  sufficient  to  double  the  average  dissolved 
oxygen  content  of  the  river  water,  in  addition  to  replenishing  that  required  for  oxidizing 
the  entire  flow  of  sewage  from  the  City  of  Philadelphia. 

The  rate  of  increase  of  the  dissolved  oxygen  in  the  Delaware  river  below  Philadel- 
phia from  the  mouth  of  the  Schuylkill  river  to  Chester,  or  7.9  miles,  the  rate  of  flow 
being  about  2  miles  per  hour,  was  computed  by  Mr.  Webster  to  be  8.6  pounds  per 
second  per  square  mile  of  river  surface,  or  743,040  pounds  per  day. 

If  we  assume  that  the  absorption  area  for  the  sewage  in  the  Delaware  and  Schuyl- 
kill rivers  between  the  points  where  sewage  is  first  received  and  the  point  where  the  Del- 
aware has  recovered  its  normal  condition  is  about  28  square  miles  and  the  population 
whose  raw  sewage  enters  the  river  is  about  1,800,000  persons,  then  on  the  average  1 
square  mile  of  river  surface  will  serve  about  64,000  persons.  The  sludge  is  practically 
removed  by  deposition  near  the  sewer  outfalls  and  in  the  Schuylkill  river.  If  the  or- 
ganic and  volatile  matter  contained  in  sewage  is  77  grams  per  capita  per  day,  then  the 
amount  of  such  sewage  matter  which  is  decomposed  by  the  oxygen  absorbed  from  the 
air  on  one  square  mile  of  flowing  land  water  surface  should  be  on  the  average  nearly 
5,000  kilograms  or  11,000  pounds  per  day. 

Recommendations  of  the  Commission 

In  taking  a  very  broad  view  of  the  entire  subject,  the  Commission  has  given 
thought  to  almost  every  conceivable  solution  of  the  problem  before  it.  At  the  outset, 
after  brief  consideration,  it  has  ruled  out  some  of  them  as  impracticable  on  account  of 
the  cost.  Thus  the  Commission  rejected  a  single  distant  sea  outfall  and  the  treatment 


REPORT  OF  RUDOLPH  HERING 


241 


of  the  sewage  at  one  or  at  several  plants  by  oxidation  in  sprinkling  filters  or  on  irri- 
gation fields.  These  rejections  are  proper,  and  any  serious  consideration  of  such  means 
for  disposing  of  the  Metropolitan  sewage  should  be  permanently  abandoned. 

The  Commission  has  not  considered  any  solutions  for  the  disposal  of  the  sewage 
from  New  Jersey,  lacking  authorization  to  do  so.  It  has,  however,  given  that  disposal 
such  general  consideration  that  the  recommendations  for  New  York  would  allow  sim- 
ilar recommendations  to  be  adopted  for  the  sewage  of  New  Jersey,  quite  independently 
of  those  now  suggested  for  New  York. 

The  New  York  portion  of  the  Metropolis  has  been  divided  into  four  subdivisions. 
In  all  of  them  the  sewage  is  collected  so  that  it  can  be  delivered  at  points  as  near  as 
possible  to  some  deep,  tidal  channels. 

This  division  has  the  advantage  of  giving  relief  to  the  most  important  points  at  the 
earliest  possible  day,  and  of  making  it  practicable  to  apply  a  relief  either  to  one  divi- 
sion or  to  another,  without  waiting  for  the  completion  of  the  whole  system. 

I  shall  refer  to  those  divisions  not  in  the  order  given  by  your  Commission,  but  in 
an  order  which  will,  I  think,  better  facilitate  the  giving  of  my  opinion  as  to  "the  neces- 
sity and  sufficiency  of  the  plans  proposed."  I  have  also  separated  your  second  division 
into  two,  calling  one  the  "Hudson  river"  and  the  other  the  "Lower  East  river"  division. 

1.    Hudson  River. 

The  territory  included  in  this  division  is  the  entire  west  side  of  Manhattan  Island, 
which  now  drains  into  the  Hudson  river.  You  say  (Prel.  Rpt.  VI,  page  39)  :  "The 
water  of  the  Hudson  will  be  capable  of  assimilating  the  sewage  produced  on  the  west 
side  of  Manhattan  Island." 

I  am  fully  in  accord  with  this  view.  You  propose  that  the  dry-weather  sewage 
"should  be  passed  through  grit  chambers  and  screened  and  so  discharged  into  the  wa- 
ter as  to  insure  prompt  diffusion."  This  recommendation  likewise  in  general  accords 
with  my  views. 

For  the  final  detailed  plans  every  single  outfall  should  be  specially  studied.  In 
some  cases  it  may  be  more  effective,  if  desirable  and  if  there  is  sufficient  space,  to  have 
the  suspended  matters  retained  by  floatage  rather  than  by  screens.  There  can  be  no  ob- 
jection to  having  gravel  or  sand  enter  the  harbor  hereafter  as  heretofore,  and  it  is 
cheaper  to  remove  it  by  dredging  from  the  harbor  than  by  hand  from  basins  or 
chambers. 

Where,  however,  fine  screen  are  preferable  for  local  reasons  then  grit  chambers  are 
necessary  to  protect  the  screens  and  facilitate  their  operation.  Grit  chambers  are  also 
necessary  where  coarse  heavy  material  is  expected  and  the  sewage,  having  contained 
such  grit,  is  to  be  pumped  or  carried  quite  a  distance  from  the  shore  to  the  point  of 
outfall.  Where  the  gravel  and  sand  can  be  discharged  into  the  river  at  the  shore,  as 
noAv,  to  be  removed  by  dredging,  and  only  the  sewage  discharged  further  out  into  the 
channel  it  would  be  economical  to  do  so. 

I  heartily  agree  also  with  the  proposition  that  the  sewage  be  discharged  as  nearly 
as  possible  into  the  channel  current  by  means  of  submerged  pipes  having  a  number  of 
openings  discharging  as  nearly  horizontal  as  practicable.  It  is  the  best  of  the  simple 
means  of  dispersion  of  the  sewage  in  a  current.  I  am  aware,  however,  of  the  difficulties 
encountered  when  considering  the  interests  of  navigation.  Where  the  channel  has  a 
depth  well  below  the  established  harbor  depth  there  should  be  no  difficulties.  Other- 
wise satisfactory  agreements  must  be  made  with  the  United  States  Government. 


242 


REPORTS  OF  EXPERTS 


2.    Upper  East  River  and  Harlem. 

The  plans  you  have  proposed  for  this  second  division  have  the  ohject  of  removing 
the  present  pollution  of  the  Harlem  river,  to  provide  for  a  proper  sewage  discharge 
into  the  Upper  East  river  and  to  prevent  a  large  part  of  the  present  pollution  of  the 
Lower  East  river  during  ebh  tide.  You  have  divided  the  area  into  five  subdivisions, 
which  seem  to  have  been  carefully  limited,  so  that  the  best  conditions  for  collection  and 
discharge  have  been  reached. 

The  outfalls  are  all  located  at  favorable  points,  where  the  water  is  deep  and  the 
currents  are  rapid.  The  general  locations  are  favorable  also  towards  keeping  the  sew- 
age discharged  well  towards  Throgg's  Neck,  or  rather  as  far  away  from  the  Lower  East 
river  as  practicable. 

The  Harlem  river  for  a  large  part  of  its  length  is  quite  objectionably  polluted 
both  by  sewage  and  by  sludge  deposits.  The  only  solution  of  the  Harlem  river  prob- 
lem is,  first  to  keep  the  river  well  dredged  and  free  from  sludge  deposits  and  to  inter- 
cept the  sewage  now  discharged  into  it. 

You  have  selected  the  northeast  part  of  Wards  Island  as  the  place  where  the  sew- 
age from  the  Harlem  subdivision  is  to  be  delivered  and  treated.  This  location  for  an 
outfall  is  a  good  one  and  there  is  sufficient  room  apparently  available  for  the  intended 
purposes. 

It  would  be  of  little  avail  to  discharge  the  sewage  intercepted  from  the  Harlem 
river  at  a  nearer  point,  because  much  of  the  sewage  would  quickly  return  with  the  tide. 
On  Wards  Island  it  is  discharged  into  the  Hell  Gate  current,  where,  after  intercept- 
ing the  floating  matter,  it  would  be  lost  to  view.  Sufficient  land  should  be  secured  to 
erect  also  settling  basins  for  the  retention  of  the  sludge  as  soon  as  this  will  be  found 
necessary. 

Rikers  Island  is  unsuitable  for  sewage  treatment  for  evident  reasons.  Sunken 
Meadow,  although  beset  with  other  difficulties,  is  the  only  alternate  practicable  location 
in  the  neighborhood,  if  Wards  Island  should  not  be  available. 

If  the  East  river  is  deepened  and  the  channel  widened,  as  proposed,  the  conditions 
for  dispersion  of  the  Harlem  river  sewage  and  for  its  oxidation  will  be  improved. 

The  location  for  outfall  and  treatment  works  at  Clason  Point,  as  proposed  by 
your  Commission,  is  apparently  the  best  one  for  discharging  the  sewage  from  the  area 
that  you  have  drained  to  it,  into  deep  water  as  quickly  as  practicable. 

The  outfalls  for  the  remaining  three  subdivisions,  situated  on  the  southeast  side  of 
the  Upper  East  river,  are  also  well  located  to  get  a  thorough  and  quick  dispersion  of  the 
sewage  at  depths  of  at  least  30  feet  and  from  as  many  outlets  across  the  current  as 
practicable. 

In  all  cases  the  outfalls  appear  to  require  the  least  expenditure  of  money  for  col- 
lection as  well  as  disposal. 

You  have  quite  properly  recommended  screening  and  retention  of  the  floating  mat- 
ter at  all  of  these  outfalls.  The  outfall  sewers  should  be  so  designed  and  pumping  sta- 
tions so  placed  that  it  will  not  be  difficult  to  install  suitable  settling  tanks  hereafter, 
when  they  may  be  required  by  the  condition  of  the  river.  In  my  opinion  sufficient  land 
should  soon  be  secured  in  every  case  where  plants  are  required  for  use  in  the  future. 

Regarding  sewer  systems  for  collection,  you  very  properly  prefer  the  separate  sys- 
tem where  sewage  is  to  be  pumped  and  treated  to  a  high  degree  of  purity.  You  also 
approve  of  the  custom  that  where  sewers  are  already  built  on  the  combined  system  this 
system  should  be  continued. 


REPORT  OF  RUDOLPH  HERING 


243 


For  the  last  35  years  it  has  been  recognized  in  Europe  and  America  that  the  sepa- 
rate system  is  the  better  one,  because  more  economical  when  the  sewage  must  be  given  a 
high  grade  of  purity,  when  it  must  be  pumped  and  when  subsurface  storm  water  removal 
can  be  postponed,  but  sewage  removal  is  an  immediate  necessity. 

Where  the  combined  system  has  been  built  you  naturally  do  not  consider  it  wise  to 
change  it,  because  the  advantages  in  the  cost  of  any  treatment  would  not  be  balanced 
by  the  cost  of  a  new  installation  of  sewers. 
3.    Jamaica  Bay. 

The  Commission  has  reported  two  projects  for  the  division  which  naturally  drains 
into  Jamaica  bay.  One  confines  the  sewage  disposal  to  its  own  area,  the  other  consid- 
ers a  combination  with  the  sewage  from  the  subdivision,  which  is  to  be  mentioned  under 
caption  V.  Here  only  the  first  one  will  be  considered.  Whatever  may  be  the  specific 
plan  of  development  of  the  Jamaica  bay  division,  it  is  clear  that  no  raw  sewage  should 
be  permanently  discharged  into  it,  that  whatever  sewage  flows  into  it  naturally  should 
receive  a  treatment  to  prevent  all  nuisance,  and  that  the  treatment  in  the  future  should 
be  of  a  higher  order  than  in  any  of  the  other  sewerage  divisions  because  the  effluent  en- 
ters a  small  and  shallow  inland  bay. 

The  plan  of  the  Commission  is  to  intercept  the  sewage  of  the  whole  territory  and 
deliver  it  at  two  points.  One  point  is  Jo  Co.'s  Marsh,  an  island  in  the  bay,  to  which  is 
delivered  the  sewage  from  the  area  of  the  eastern  subdivision  between  Rockaway  in  the 
south  and  Creedmore  in  the  northeast.  The  other  point  is  Barren  Island,  to  which  is 
delivered  the  sewage  from  the  area  of  the  western  subdivision  between  Coney  Island 
and  Jamaica. 

The  sewage  is  to  be  collected  by  the  separate  system  so  far  as  possible,  otherwise  it 
is  to  be  intercepted  from  combined  sewers,  to  allow  as  little  as  possible  of  the  first 
street  surface  washing  and  sewage  to  get  into  the  bay.  The  first  wash  from  the  streets, 
whether  in  the  combined  system  or  in  the  storm  drains  of  a  separate  system,  being  often 
quite  polluted  and  sometimes  more  so  than  American  dilute  sewage,  it  should  be  in- 
tercepted in  both  systems  and  turned  into  the  sewers  for  purification  and  thus  pre- 
vented from  reaching  the  bay. 

I  entirely  agree  with  your  Commission  in  opposing  long  canals  in  this  territory 
for  the  reception  and  discharge  of  sewage.  They  would  certainly  become  a  nuisance 
and  injure,  if  not  stop,  the  development  of  the  nearby  territory.  Such  canals,  if  built, 
should  be  for  the  removal  of  surface  water  alone,  and  the  house  sewage  should  be  car- 
ried to  its  final  discharge  in  separate  pipes.  The  additional  cost  of  the  separate  pipes 
would  be  more  than  repaid  by  the  improved  value  of  the  land  near  the  canals. 

The  treatment  works  on  Barren  Island  are  estimated  to  require  about  100  acres, 
which  can  be  furnished  with  settling  tanks  and  further  means  of  treatment  by  sprinkling 
filters,  if  required.  The  location  seems  well  adapted  for  a  final  disposal  of  the  sewage 
and  for  giving  it  whatever  treatment  may  be  necessary.  This  point  of  discharge,  after 
the  sewage  has  had  its  floating  and  suspended  matter  removed  by  sedimentation  tanks, 
is,  in  my  opinion,  the  best  one  now  available.  It  insures  a  sufficient  dispersion  and  high 
dilution  of  the  tank  effluents,  so  that  in  my  opinion  at  no  time  in  the  future  any  objec- 
tionable results  would  appear,  either  in  Jamaica  bay  or  along  the  beaches  of  Coney 
Island  or  Rockaway. 

The  treatment  works  on  Jo  Co.'s  Marsh  would  be  for  the  purpose  of  discharging 
the  effluent  into  Jamaica  bay  at  all  times.  This  location  also  appears  to  be  the  best  one 
for  treatment  works  and  you  have  estimated  that  30  acres  of  land  be  reserved  for  them. 


244 


REPORTS  OP  EXPERTS 


Owing  to  the  confinement  in  the  bay  the  treatment  should  be  more  thorough  than  at 
Barren  Island.  Besides  sedimentation  there  should  at  once  be  an  oxidation  of  the  efflu- 
ent by  sprinkling  filters  and  then  a  discharge  near  the  bottom  of  the  bay. 

I  do  not  believe  that  the  effect  of  final  settling  basins  would  eventually  be  worth 
their  cost  under  the  conditions  of  this  outfall.  Only  if  the  oyster  and  clam  industry  in 
the  bay  is  not  abandoned,  as  in  my  opinion  it  should  be,  and  eventually  certainly  will  be, 
will  it  be  necessary  to  add  final  settling  basins  in  order  to  have  the  effluent  dosed  with 
disinfectants  so  as  to  reduce  the  danger  of  infecting  the  shell-fish. 

You  have  also  studied  the  case  where  a  pumping  station  and  settling  basins,  erected 
near  the  bay  side  at  Arverne,  would  allow  the  effluent  to  be  more  economically  and  effi- 
ciently discharged  about  4,000  feet  from  shore  into  deep  water  and  ocean  currents.  No 
floating  matter  would  drift  towards  the  shore  and  no  depositing  matter  would  interfere 
with  navigation  or  drift  landwards.  The  liquid  sewage  would  be  readily  oxidized  in 
the  large  current  of  sea  water  into  which  it  discharges. 

This  project  appears  to  me  to  have  much  merit.  If  a  discharge  into  the  ocean  is 
found  to  be  more  economical  it  would  be  also  more  effective  and  offer  a  greater  protec- 
tion to  the  inhabitants  than  a  disposal  in  the  bay,  because  the  effluent  water  flowing  out 
is  liable  to  have  contact  with  a  long  shore  line,  instead  of  being  carried  away  in  a  cur- 
rent parallel  with  and  several  thousand  feet  away  from  the  shore.  In  neither  case 
would  there  be  floating  matter  to  strand  nor  sludge  to  drift  ashore. 
4.  Richmond. 

The  disposal  of  the  sewage  from  Richmond  affords  few  difficulties.  The  sewers 
now  existing  are  built  on  the  combined  system,  except  in  a  few  instances.  It  is  the  in- 
tention to  carry  the  sewers  to  the  pier  heads  for  discharge.  At  a  number  of  points  this 
plan  may  not  be  satisfactory,  even  if  the  sewage  is  discharged  into  deep  water,  this  is, 
as  far  as  practicable  from  shore,  as  you  have  intended  in  the  other  divisions. 

You  state  that  the  most  favorable  place  to  ultimately  discharge  the  sewage  is  at 
one  point  in  the  tidal  waters  near  the  Narrows,  but  that  this  would  not  be  economical. 
I  fully  agree  with  you  regarding  this  conclusion. 

You  have,  therefore,  subdivided  the  borough  into  areas  and  have  collected  the  sew- 
age in  each  one,  so  as  to  separately  dispose  of  it  at  economical  points.  It  is,  of  course, 
very  much  better  to  discharge  the  sewage  at  the  bottom  of  a  good  channel  than  at  the 
shore.  But  it  may  in  some  cases  be  more  economical  to  do  the  latter  than  to  gather  the 
sewage  by  interception  to  a  few  points,  at  which  submerged  pipes  are  carried  out  into 
the  channel.  In  my  opinion  it  will  be  a  question  for  local  study  and  estimate  to  decide 
between  the  two  plans.  As  a  general  proposition  numerous  outlets  give  a  better  disper- 
sion than  a  single  one  into  the  same  current,  but  there  should  be  a  current  between  the 
outlet  and  the  shore. 

While  I  consider  it  a  wise  policy  to  secure  and  retain  in  this  division  sufficient 
land  at  the  proposed  outfall  stations  for  treatment  works,  such  as  the  Commission  has 
proposed,  I  am  convinced,  with  the  Commission,  that  such  treatment  need  not  be  more 
at  the  present  time  than  to  keep  out  of  the  bay  all  floating  matter  and  in  the  Arthur  Kill 
and  opposite  Newark  bay  also  the  sludge.  Experience  will  indicate  how  soon  in  each 
case  a  more  thorough  purification  is  required.  The  works  should  therefore  be  so  de- 
signed that  they  permit  additions  to  be  made  for  more  complete  treatment  when  neces- 
sary in  the  future. 

Regarding  grit  chambers,  the  remarks  made  above  would  apply  also  here.  When 
settling  basins  are  required,  it  seems  to  me  cheapest  to  take  the  sludge  out  to  sea  than 
to  dispose  of  it  nearby,  unless  the  sludge  is  of  the  inoffensive  kind. 


REPORT  OF  RUDOLPH  HERING 


245 


5.    Lower  East  River. 

When  discussing  above  the  subject  of  dissolved  oxygen  in  the  harbor  waters,  I  ex- 
pressed the  opinion  that,  if  the  floating  matter  of  the  sewage  were  removed  and  the 
sludge  prevented  from  accumulating  on  the  harbor  bottom,  the  remainder  of  the  sew- 
age could  be  oxidized  in  the  harbor  waters  for  some  time  without  objectionable  effects. 

This  opinion  related  to  the  average  of  the  entire  harbor.  Unless  there  is  a  uniform 
distribution  of  the  sewage  within  it,  the  conclusion  would  not  apply  under  present  con- 
ditions to  every  part  of  it.  The  Lower  East  river  is  without  question,  at  present,  the 
most  polluted  part  of  the  harbor,  not  mentioning  the  Harlem  river,  and  any  perma- 
nently satisfactory  solution  for  the  entire  harbor  should  embody  means  for  removing 
especially  the  aggravated  evils  of  this  portion. 

You  have  recommended  such  a  solution  by  collecting  the  sewage  now  entering  the 
East  river  and  taking  it  to  an  artificial  island  to  be  built  in  the  Lower  bay,  between 
Coney  Island  and  Sandy  Hook,  there  to  be  discharged,  after  whatever  treatment  might 
be  necessary.  The  expense  of  construction  and  operation  of  this  project  is  large.  In 
justification  thereof  you  have  given  a  number  of  reasons.  I  shall  now  comment  upon 
them  and  feel  obliged  to  maintain  the  view  that  the  adoption  of  this  project  is  not 
warranted  at  the  present  time. 

You  first  mention  the  large  areas  of  low  and  made  land  in  lower  Manhattan  and 
Brooklyn  which  causes  the  main  outfall  sewers  to  be  of  very  flat  grade  and  for  large 
areas  below  high  water.  These  conditions  are  not  satisfactory.  They  cause  the  sewage 
to  deposit  much  of  its  suspended  matter,  which  putrefies  and  develops  offensive  odors 
from  gases  and  air  escaping  at  the  manholes,  and  the  putrefying  sludge  is  flushed  into 
the  harbor  by  rainstorms.  The  sewage  is  generally  somewhat  septic  when  discharged, 
but  if  it  is  discharged  at  the  bottom  of  the  harbor  and  beyond  the  pier  heads  the  septic 
condition  would  soon  be  removed  by  the  dispersion  of  the  sewage  in  oxygenated  water. 
Some  of  the  sludge,  having  entered  into  decomposition  in  the  sewers,  will  have  corre- 
spondingly less  decomposition  to  undergo  when  deposited  on  the  harbor  bottom. 

To  overcome  the  objectionable  condition  on  shore,  within  the  areas  where  the  pres- 
ent sewers  are  below  high  tide,  it  has  long  ago  been  suggested  to  build  separate  sewers 
for  sewage  removal,  with  better  grades  than  at  present  and  to  lift  the  sewage  by  pump- 
ing.  This  suggestion  still  has  merit. 

You  further  mention  some  of  the  present  physical  conditions  of  the  sewers,  which 
are  undoubtedly  objectionable,  such  as  the  lack  of  cleanliness,  accumulation  of  sludge 
and  grease  and  comparative  uselessness  of  many  of  the  catchbasins.  The  objection- 
able condition  of  the  present  sewers,  if  they  are  not  rebuilt,  can  be  removed  by  more 
care  in  the  maintenance  and  operation,  whatever  is  eventually  done  with  the  sewage 
itself.  Wherever  sufficient  slope  is  practicable,  it  is  generally  cheaper  to  omit  catch- 
basins  and  let  the  silt  and  gravel  enter  the  sewers  and  be  flushed  to  the  rivers,  there 
to  be  taken  out  by  dredges. 

You  refer  to  the  most  conspicuous  nuisances  of  the  Lower  East  river,  which  are 
Newtown  creek,  Wallabout  bay  and  Gowanus  canal.  I  am  satisfied,  from  what  has  been 
said  above,  that  the  very  objectionable  conditions  existing  in  all  three  localities  will  dis- 
appear if  the  floating  matter  and  the  sludge  deposits  are  removed.  Since  the  flushing 
channel  for  the  Gowanus  canal  has  been  built  the  canal  is  still  offensive,  notwith- 
standing the  clear  water  which  now  enters  it.  This  fact  is  due  to  the  fact  that  much 
sludge  still  covers  the  bottom  of  the  canal,  putrefying  and  sending  up  foul  gases  and 
comminuted  sludge  particles,  which  persist  long  enough  to  reach  even  the  East  river, 


246 


REPORTS  OF  EXPERTS 


to  deposit  among  the  docks  near  the  new  outfall.  Keeping  the  bottom  of  the  Gowanus 
canal  clean  by  suction  dredging  will,  in  my  opinion,  prevent  the  continuation  of  the 
nuisance  arising  therefrom. 

Wallabout  bay  and  Newtown  creek  can,  in  my  opinion,  be  treated  in  a  similar  way 
by  the  removal  and  proper  disposal  of  the  floating  matter  and  the  sludge  deposited 
therein. 

In  these  cases,  as  well  as  in  many  others,  where  the  sewers  discharge  below  high 
water  it  would  be  advisable  to  lift  the  ordinary  dry-weather  flow  with  electric  pumps 
into  settling  basins,  where  the  sludge  may  either  be  digested  or  frequently  removed  be- 
fore digestion,  in  special  barges,  as  mentioned  above. 

I  quite  agree  with  the  Commission  that  in  the  collecting  system  the  sewers  should 
have  the  first  right  of  way  beneath  the  city  streets.  A  gravity  flow  of  water,  as  in  a 
sewer,  carrying  suspended  matters  demands  a  regular  grade.  All  other  structures,  such 
as  pipes  conveying  potable  water,  gas  or  steam  under  pressure,  as  well  as  a  number  of 
other  conduits  and  subways,  can  more  readily  change  their  grades. 

The  facts  that  the  flow  of  sewage  into  the  harbor  is  irregular  as  to  time  and  that 
the  flow  of  tidal  water,  in  addition  to  not  being  uniform  during  one  tide  even,  reverses 
its  flow,  contribute  to  getting  a  better  mixture  than  if  there  were  a  more  regular  and 
constant  flow,  as  a  uniform  discharge  into  a  fresh-water  river. 

Sludge  settles  more  rapidly,  and  by  the  occurrence  of  some  coagulation  more  thor- 
oughly, therefore  it  can  be  more  expeditiously  gathered  in  salt  than  in  fresh  water. 

The  tables  which  your  Commission  has  prepared  indicate  the  relative  value  of  the 
different  bodies  of  harbor  water  for  oxidizing  sewage.  They  show  that  the  Lower  East 
river  receives  more  organic  sewage  matter  than  any  other  part  of  the  harbor,  and  that 
the  water  available  for  its  dilution  and  oxidation  is  less  per  capita  than  in  any  other 
water  of  the  harbor,  excepting  the  Harlem  river. 

There  can  be  no  question  but  that  the  sewage  flowing  into  the  Harlem  river  can  be 
intercepted  and  removed  into  the  Upper  East  river,  because  it  is  the  only  solution  pos- 
sible for  relief  from  its  nuisance,  as  mentioned  above.  I  cannot,  however,  see  equally 
good  reasons  for  intercepting  and  removing  to  the  Lower  bay  the  sewage  from  the  Lower 
East  river,  as  the  Commission  has  suggested. 

The  chief  reasons  for  this  opinion  are,  first,  that  screening  and  sedimentation  and 
a  sludge  removal  by  suction  dredges  from  the  docks  and  river  bottom  in  the  Upper  and 
Lower  East  rivers,  perhaps  also  oxidation  of  a  part  of  the  sewage  on  Blackwell's  Island, 
will,  from  what  has  been  said  above,  in  my  opinion,  remove  all  causes  of  offensiveness 
to  sight  and  smell,  not  only  now  but  for  some  time  to  come. 

Secondly,  that  the  remaining  liquid  and  fine  suspended  matter,  as  well  as  some 
sludge  deposits  that  escape  deposition,  can,  in  my  opinion,  be  sufficiently  oxidized  by  the 
waters  of  the  Lower  East  river  and  Upper  harbor  to  prevent  any  nuisance. 

Thirdly,  that  the  cost  of  removing  all  sewage  and  some  rain-water  to  the  "Outlet 
island"  is  so  large  that,  in  my  opinion,  the  relative  benefits  to  be  gained  in  excess  of 
those  gotten  by  local  and  partial  treatment,  as  above  suggested,  are  at  the  present  time 
not  justified. 

The  New  York  harbor  waters  have  a  high  financial  value  to  the  city  as  a  sewage 
oxidizer,  and  this  asset  should  be  as  completely  utilized  as  practicable  before  a  limita- 
tion is  fixed  involving  such  large  expenditures. 

A  number  of  engineers,  sanitarians  and  biologists  in  their  endeavor  to  select  a 
figure  which  would  represent  the  lower  permissible  limit  of  dissolved  oxygen  in  waters 


REPORT  OF  RUDOLPH  HERING 


247 


receiving  sewage,  have  suggested  the  figure  50  per  cent,  or  thereabouts,  below  which 
the  wrater  might  be  objectionable.  No  strong  reasons  have  been  given  to  use  this  figure 
as  a  limit,  even  as  an  average  limit. 

The  experience  above  quoted  from  London  with  its  tidal  brackish  water,  and  Phil- 
adelphia with  its  tidal  fresh  water,  indicate  that  a  much  lower  average  figure  does  not 
cause  a  nuisance.  Theoretically,  only  a  reduction  to  zero  at  any  point  might  mark  its 
beginning. 

It  has  seemed  to  me  that  much  of  the  evidence  which  has  led  to  the  round  figure  of 
50,  or  half  saturation,  was  gained  from  practical  observation  of  cases  where  sludge  was 
putrefying  on  the  bed  and  where  floating  matter,  scum  and  sleek  were  adding  to  the  ex- 
traction of  oxygen  near  the  surface. 

If  both  sludge  and  floating  matter  are  removed  the  oxygen  content  of  the  water  is 
improved.  A  condition  is  thereby  created  which  allows  without  objection  a  lower  degree 
of  saturation  with  oxygen  to  be  maintained  than  otherwise,  because  of  the  absence  of 
most  of  the  non-resistant  suspended  matter,  floating  or  attached  to  gas  bubbles  and 
liable  to  rapidty  exhaust  the  oxygen,  become  putrescent  and  cause  odors. 

Regarding  major  fish  life,  which  I  have  already  mentioned,  I  do  not  consider  this 
industry,  so  far  as  the  Lower  East  river  is  concerned,  of  sufficient  value  to  justify  the 
heavy  expense  of  maintaining  for  it  a  higher  degree  of  oxygen  in  the  water  than  might 
otherwise  be  entirely  satisfactory. 

Irrespective  of  the  large  expense  of  the  tunnel  outfall  sewer  and  of  the  large 
pumping  stations,  and  owing  to  the  uncertainties  and  difficulties  to  be  encountered  be- 
low tide  level  when  crossing  Long  Island,  to  the  proposed  Outlet  island,  possibly  incur- 
ring a  larger  expense  than  is  now  estimated,  it  is  questionable  whether,  after  the  sewage 
arrives  at  the  island  the  subsequent  condition  of  the  sewage  and  cost  of  its  treatment 
will  be  justified. 

The  tunnel  is  suggested  to  be  built  large  enough  for  a  reasonable  future.  It  will, 
therefore,  at  the  outset  cause  a  correspondingly  slower  velocity  than  in  later  years. 
The  natural  condition  of  the  sewage,  therefore,  when  arriving  at  the  island  after  about 
12  miles  flow  would  at  least  at  first  be  septic,  that  is,  offensive. 

You  propose  to  prevent  this  result  "by  aeration  to  be  provided  at  two  or  possibly 
three  points  along  the  lines."  I  am  not  convinced  that  such  a  means  would  accomplish 
the  desired  result.  I  have  recommended  aeration  at  a  pumping  station  by  injecting  air 
into  the  force  main  under  a  fairly  good  pressure  which  causes  the  air  to  be  dissolved 
and  dispersed  throughout  the  water  section.  I  am  not  sure  after  the  pressure  is  reduced 
what  the  practical  results  as  regards  odors  will  be,  in  part  due  to  the  release  of  air 
and  remaining  foul  gases  escaping  with  it.  But  I  believe  it  will  be  difficult,  if  at  all 
possible,  as  a  permanent  measure  to  aerate  the  large  sewage  flow  in  a  gravity  sewer 
across  Long  Island,  as  shown  in  the  profile,  so  as  to  penetrate  the  sewage  sufficiently 
to  accomplish  the  desired  oxidation. 

The  following  treatments  at  the  island  are  possible : 

First,  the  sewage  on  arrival  at  the  island  could  be  discharged  in  a  raw  condition. 
The  large  quantity  of  raw  sewage  with  much  comminuted  matter  might  sometimes  be 
unfavorably  noticeable  in  its  effects.  The  Commission,  therefore,  properly  proposes 
to  treat  the  sewage  before  discharge. 

Secondly,  the  sewage  can  be  passed  through  large  settling  basins — the  Dortmund 
type  is  suggested  by  your  Commission — in  which  the  sludge  is  allowed  to  deposit  and 
to  be  later  taken  out  to  sea.   The  effluent  is  discharged  into  the  bay. 


248 


REPORTS  OF  EXPERTS 


As  the  suspended  matter  after  flowing  12  miles  is  highly  comminuted,  the  time 
required  for  settling  on  the  island,  the  greater  portion  of  the  solids  will  be  increased. 
To  get  the  same  result  as  with  shorter  outfall  sewers  the  basins  would  have  to  be  larger 
and  more  expensive  than  if  nearer  the  point  of  sewage  origin.  The  sewage,  if  dis- 
charged without  bacterial  or  chemical  treatment,  would  have  more  dissolved  matter 
to  be  oxidized  in  the  Lower  bay  than  if  discharged  in  the  Upper  bay,  which  might  be  an 
advantage. 

The  sewage  rises  from  the  end  of  the  long  tunnel  into  the  open  basins.  Unless 
aerated  at  the  pumping  station,  the  odor  would  be  stronger  at  these  basins  on  account 
of  the  age  of  the  sewage  than  at  any  point  where  it  might  be  exposed  along  the  East 
river.  This  septic  sewage  odor  has  occasionally  been  perceptible  a  mile  distant.  Just 
how  much  this  odor  could  be  reduced  by  a  single  aeration  at  the  pumping  station  I  am 
not  prepared  to  say. 

The  application  of  a  disinfecting,  coagulating  and  precipitating,  oxidizing  or  aera- 
ting plant  as  suggested  would  add  correspondingly  to  the  cost.  If  any  of  such  plants 
were  resorted  to  at  the  Outlet  island  the  results  could  be  no  better  than  if  used  near 
the  East  river ;  for  instance,  on  the  shoals  below  Governors  Island,  except  that  in  the 
Lower  bay  any  nuisance  could  not  be  so  readily  perceived.  An  oxidizing  plant  in 
the  Upper  bay  in  the  form  of  coarse-grained  filters  or  other  means,  is  not  liable,  other 
things  equal,  to  be  as  septic  and  odorous  as  at  the  more  distant  island.  A  disinfecting 
plant  would  probably  not  be  necessary  at  any  point  in  the  harbor  and  an  aerating,  pre- 
cipitating and  sludge  plant  could  as  well  be  placed  in  the  Upper  as  in  the  Lower  bay, 
and  from  experience  elsewhere  need  not  be  offensive.  The  advantages  as  regards  treat- 
ment works  on  the  Outlet  island  in  the  Outlet  island  in  the  Lower  bay  over  a  treatment 
nearer  by  do  not  appear  to  me  to  be  very  material.  At  any  rate,  I  believe  the  decision 
can  be  postponed  without  any  danger  to  health  or  from  a  continuation  of  the  present 
nuisance,  if  suspended  matters  and  sludge  deposits  are  removed. 

The  new  island  in  the  Lower  bay  could  be  made  strong  enough  to  resist  the  effects 
of  wind  waves  in  high  storms,  but  it  will  be  expensive  to  do  this,  and  it  will  require  the 
continuous  presence  on  the  island  of  a  suitable  force  of  men. 

I  am  informed  that  your  Commission  is  considering  treatment  of  the  Lower  East 
river  sewage  on  Governor  Island  or  on  the  shallow  area  south  of  the  same.  If  physical 
and  legal  conditions  permit,  I  consider  such  a  project  preferable  to  the  Lower  bay 
project,  not  only  on  account  of  less  cost,  but  of  better  control.  The  effluent  could  be 
discharged  into  the  waters  of  the  Upper  bay  and  Hudson,  which  your  Commission  have 
found  at  present  to  be  those  which  are  least  charged  with  sewage. 

The  treatment  works  have  been  considered  by  you  as  consisting  of  sedimentation 
tanks,  such  as  those  of  the  Imhoff  type,  giving  inoffensive  sludge.  If  the  collecting 
sewers  are  kept  well  cleaned  there  is  no  reason  why  the  sewage  when  delivered  should 
not  be  inoffensive,  and  therefore,  why  oxidation  by  means  of  sprinkling  filters  or  other 
means  would  not  also  be  an  inoffensive  process.  Owing  to  the  scarcity  of  land  avail- 
able, the  works  would  have  to  be  designed  to  give  the  greatest  intensity  of  treatment. 
The  degree  to  which  such  treatment  is  carried,  however,  need  not  be  higher  than  the 
character  of  the  Upper  bay  water  justifies. 

I  am  not  of  the  opinion  that  a  sewage  treatment  plant  on  Governors  Island  or  on 
any  other  area  below  would  be  necessary  at  once.  I  believe,  however,  that  studies 
should  now  be  made  far  enough  ahead  to  determine  the  approximate  time  when  an  oxi- 
dation of  the  sewage  should  follow  the  present  necessity  for  removing  the  solid  matter, 


REPORT  OF  RUDOLPH  HERING 


249 


that  land  should  be  secured  while  it  is  available,  and  a  project  soon  adopted  which  will 
best  serve  the  city  in  the  more  distant  future. 

The  Commission  gives  the  ratio  of  crude  or  raw  sewage  to  the  harbor  water  in  the 
Lower  East  river  division  at  1  : 244,  while  that  for  the  Upper  bay  is  1  : 2920.  There- 
fore, when  the  sewage  going  into  the  Lower  East  river  must  be  oxidized  it  appears  that 
the  Upper  bay  can  receive  for  some  time  without  detriment  a  very  large  part,  if  not  all 
of  it,  as  well  as  the  New  Jersey  partially  treated  sewage. 

I  do  not  hold  the  opinion  that,  considering  the  oxidizing  power  of  the  New  York 
harbor  water  we  should  depend  only  upon  the  tidal  prism,  with  the  ratio  of  sewage  to 
water  as  1  : 32.3,  nor  upon  the  net  ebb  flow,  with  the  ratio  of  sewage  to  water  as 
1  : 5.9  as  taken  from  your  tables.  The  waters  of  the  entire  river  section  are  well 
intermingled,  as  pointed  out  by  the  Commission  through  its  dissolved  oxygen  figures; 
therefore,  it  seems  to  me  that  we  should  not  apply  the  latter  two  ratios  to  the  pollu- 
tion of  the  whole  water  capacity  with  which  we  are  dealing. 

The  first  ratio  given  above,  namely,  1  part  sewage  to  244  parts  water,  would 
correspond  more  nearly  with  the  actual  dilution  than  the  ratio  of  1  part  to  32.3.  But 
it  can  be  considered  only  as  an  average  at  present  with  wide  local  variations. 

The  Commission  further  says :  "It  is  wrong  to  speak  of  sewage  matters  as  sew- 
age 2  or  3  hours  after  they  have  been  discharged  into  a  tidal  estuary.  Some  of  the 
ordinary  ingredients  may  still  exist,  but  the  chances  are  all  against  the  continuance 
of  any  of  them  in  an  unaltered  condition,  except  the  grosser  solids  and  such  others  as 
may  be  able  to  persist  in  greatly  diluted  form." 

This  statement  confirms  the  fact  that  soon  there  is  a  separation  of  floating  and  de- 
positing matter  from  the  dissolved  and  fine  suspended  or  colloidal  matter,  that  more 
and  more  matter  is  continually  dissolving  and  that  the  arguments  relating  to  crude  sew- 
age then  no  longer  hold.  There  is  a  substantial  separation  of  the  sewage  into  three 
parts,  each  one  of  which  must  later  be  given  separate  consideration,  because  each  be- 
comes more  and  more  unlike  the  others  in  character  and  quantity  and  ultimately 
requires  separate  treatment.  The  conclusions  reached  from  data  relating  to  raw  sew- 
age, therefore,  cannot  be  applied  to  any  one  of  its  three  parts  after  it  has  passed  its 
first  stage  of  disintegration. 

As  the  only  one  of  the  three  parts  of  the  sewage  which  can  be  left  in  the  harbor 
water  is  that  representing  the  liquid  and  fine  suspended  matter,  and  also  the  part  most 
quickly  oxidized  by  the  water,  it  is  my  opinion  that  the  amount  of  sewage  represented 
by  the  liquid  portion  which  can  be  digested  by  the  harbor  water  will  be  materially 
larger  than  that  which  has  been  deduced  from  the  usual  laboratory  experiments. 

The  Lower  East  river  should  therefore  be  able  to  receive  the  liquid  and  fine  sus- 
pended matter  reaching  it  for  many  years  longer  than  it  can  receive  the  crude  sewage. 
When  the  limit  has  been  reached  beyond  which  offense  would  occur  some  of  this  liquid 
sewage  may  be  intercepted  and  carried  elsewhere  to  be  discharged,  at  first  perhaps  di- 
rectly into  the  less  oxygen-depleted  waters  of  the  Upper  bay  and  later  receive  some  oxi- 
dation or  other  treatment  before  its  final  discharge. 

All  the  floating  matter  in  this  division  should  be  intercepted  at  once  and  the  solid 
matter  collected  in  settling  basins  where  practicable,  or  otherwise  frequently  removed 
from  near  the  sewer  outfalls  by  suction  dredges. 

If  the  outfall  sewer  to  Outlet  island  should  be  built,  the  western  branch  of  the 
Jamaica  bay  intercepting  sewer,  as  you  have  proposed,  would  also  be  connected  with  it, 
instead  of  discharging  at  Barren  Island.    If  Outlet  island  is  not  built,  the  Barren 


250 


REPORTS  OF  EXPERTS 


Island  project  as  outlined  by  you  would  give  a  good  disposal  for  the  sewage  from  the 
respective  territory. 

Resume  and  Conclusions 

The  sewage  problem  in  New  York  is  more  complex  than  in  any  other  large  city,  as 
the  work  of  your  Commission  has  demonstrated.  Its  solution  depends  upon  scientific 
knowledge  and  practical  experience. 

It  can  be  aided  by  results  satisfactorily  obtained  elsewhere  under  similar  condi- 
tions. 

It  depends  also  largely  upon  the  opinions  and  desires  of  the  inhabitants.  Some 
conditions  and  some  people  will  demand  higher  standards,  and  therefore  generally 
greater  expenditures  for  some  cities  than  for  others.  This  circumstance  has  occasion- 
ally made  the  solution  difficult  and  slow  of  adoption. 

Municipal  expenditures  should  be  divided  in  such  proportions  among  the  different 
demands  of  a  community  that  the  results  obtained  are  fairly  well  balanced  in  all  direc- 
tions. No  excessive  benefits  should  be  secured  for  one  public  work  at  the  sacrifice  of 
having  an  insufficient  benefit  from  another.  For  instance,  in  my  opinion  we  should 
distribute  the  expenditures  for  the  collection  and  the  disposal  of  the  Metropolitan  sew- 
age in  such  proportion  that  the  works  for  collection,  because  nearer  to  our  inhabitants 
and  the  locations  where  we  spend  most  of  our  time,  receive  an  expenditure  which  will 
give  equal  benefit  to  that  which  should  be  desired  from  the  final  disposal  of  the  sewage. 
In  Europe  this  proportionate  expenditure  generally  receives  more  attention  than  here. 
Sir  Robert  Rawlinson,  who  may  perhaps  be  designated  as  the  father  of  modern  sewer- 
age, asked :  "Is  it  better  to  pollute  rivers  or  pollute  towns  and  houses — to  kill  fish  or 
to  kill  men?" 

In  seeking  a  solution  the  Commission  has  taken  a  broad  view  and  collected  a  very 
large  amount  of  information,  which  is  and  will  be  valuable  in  solving  the  sewage  prob- 
lem of  the  Metropolis.  It  has  made  surveys,  analyses,  inspections,  compilations  and 
studies  to  a  greater  extent  than  has  ever  been  done  before. 

The  problem  may  be  divided,  in  my  opinion,  into  three  groups:  one  relating  to 
health,  another  to  nuisance  and  the  third  to  cost. 

The  health  factor  is  judged  by  the  liability  of  the  works,  devised  for  collecting  and 
disposing  of  the  sewage,  to  transmit  disease  germs  from  sewers,  bathing,  consuming 
shell-fish  and  having  contact  with  stranded  objects.  The  nuisance  factor  is  judged  by 
the  offensiveness  to  sight  and  smell.  The  cost  factor  is  judged  by  the  ability  and  will- 
ingness of  a  community  to  pay  the  price  of  the  improved  conditions. 

The  physician  usually  deals  with  the  first,  the  engineer  with  the  second  and  the  pub- 
lic must  deal  with  the  third  group. 

Experience  has  shown  that  works  intended  to  prevent  a  nuisance  usually  prevent 
also  the  transmission  of  disease  germs.  The  problem  in  its  most  abbreviated  form  is, 
therefore,  reduced  substantially  to  cleanness  of  sewers  and  harbor  and  to  the  most  eco- 
nomical means  of  securing  this  result.  The  cost  should  be  considered  in  terms  of  the 
desired  degree  of  relief  from  unhealthfulness  and  nuisance,  which  in  the  case  of  our 
Metropolis  will,  I  feel  sure,  not  be  unreasonably  limited. 

The  work  of  the  Commission  has  been  extended  chiefly  to  the  problem  of  sewage 
disposal.  It  has  made  a  very  thorough  study  of  the  application  of  all  of  the  known 
means  of  sewage  treatment  for  the  entire  Metropolitan  area.  It  has  also  examined  into 
the  treatments  found  elsewhere.    Although  sewage  varies  in  quantity  and  quality  ac- 


REPORT  OF  RUDOLPH  HERING  251 

cording  to  the  character  and  occupation  of  the  population,  it  is  remarkably  similar  in 
its  behavior  under  the  different  conditions,  both  when  discharged  into  water  or  upon 
land.  Experiences  in  even  somewhat  dissimilar  cities  can,  therefore,  be  utilized  and 
furnish  help  to  form  opinions  in  new  cases. 

The  Commission  has  accepted  the  latest  theories  of  sewage  purification  and  of  the 
means  of  judging  and  measuring  the  most  efficient  conditions  and  results. 

It  has  made  extensive  analyses  of  the  harbor  water  at  different  locations  and 
depths,  both  chemically  and  with  reference  to  bacterial  contents,  and  especially  to 
those  indicating  the  presence  of  sewage.  It  has  made  these  analyses  at  different  stages 
of  the  tide  and  at  different  seasons.  It  has  studied  the  currents  and  the  circulation  of 
the  harbor  waters  more  in  detail  than  was  done  before. 

The  Commission  has  accepted  the  recent  conclusion  that  sewage  and  its  suspended 
matter,  which  once  on  theoretical  grounds  was  considered  valuable  on  land  and  here 
and  there  was  temporarily  sold  at  good  prices,  is  now  on  practical  grounds  considered 
much  less  valuable  than  originally  supposed,  and  is  moreover  liable  to  become  a  nui- 
sance. The  conclusion  at  the  present  day  in  most  cases,  therefore,  is  that  sewage  should 
be  purified  by  nature's  method  of  converting  dead  organic  matter  into  mineral  matter 
by  biological  processes.  The  natural  methods  are :  in  water  an  oxidation  by  the  oxy- 
gen contained  in  solution,  and  on  land  by  the  oxygen  contained  in  the  air. 

I  agree  with  the  Commission  that  the  floating  sewage  matter,  recognizable  as  such, 
should  be  removed  and  that  no  thick  films  of  grease,  oil  or  tar  should  be  seen  upon  the 
waters,  although  small  quantities  of  oily  sleek  should  be  permissible  as  unavoidable  in 
a  harbor. 

I  also  agree  with  the  conclusion  that  no  sludge  accumulations  should  be  allowed  in 
the  harbor,  and  particularly  in  the  docks  and  slips  where  it  is  most  likely  to  be.  A 
higher  standard  might  well  exist  for  the  water  in  the  docks  and  slips  than  for  that  out 
in  the  channel. 

I  do  not  consider  it  practicable  to  make  bathing  safe  within  the  harbor,  nor  to 
consume  shell-fish  that  are  taken  within  the  same. 

Nor  do  I  consider  it  practicable  or  advisable  to  fix  upon  any  uniform  standard  of 
cleanliness  or  of  oxygen  contained  for  the  waters  of  the  entire  harbor.  In  those  of  its 
parts  where  economy  demands  a  greater  digestive  power  for  the  sewage  without  pro- 
ducing any  nuisance,  the  standard  may  well  be  lower.  Where  it  is  not  economical  to 
draw  down  the  oxygen  content  very  low  it  will,  of  course,  be  advisable  to  maintain  a 
higher  standard.  If  any  standards  may  be  fixed  in  the  different  parts  of  the  harbor 
they  should,  in  my  opinion,  be  based  on  the  most  economical  means  for  preventing  a 
nuisance  from  arising  at  any  time. 

I  accept  the  Commission's  conclusion  that  wherever  possible  the  sewage  should  be 
discharged  through  submerged  outlets  into  a  current  the  nearest  available,  and  not  at 
the  shore.  Whatever  means  are  practicable  they  should  secure  as  great  a  dispersion  of 
the  sewage  in  the  current  as  possible. 

In  order  to  prevent  floating  matter  from  entering  the  rivers,  screens,  settling 
basins  or  floatage  chambers  should  be  built  at  the  sewer  outlets. 

Grit  chambers  are  suggested  by  the  Commission  to  collect  the  grit  from  the  sew- 
age. It  is  cheaper  to  dredge  the  grit  from  the  river  than  to  take  it  out  of  a  grit  chamber 
or  catchbasins.  It  is  necessary,  therefore,  to  determine  in  each  local  case  which  dispo- 
sition should  be  made.   Where  Imhoff  tanks  for  sludge  digestion  are  built  or  where  the 


252 


REPORTS  OF  EXPERTS 


sewage  must  pass  through  pumps  it  is  usually  found  better  to  previously  intercept  the 
grit  for  separate  removal. 

I  do  not  consider  the  existence  of  turbidity  due  to  rainfalls  in  the  drainage  area  of 
the  Hudson  valley  objectionable  even  if  it  were  preventable,  which  it  is  not.  Nor  do  I 
consider  a  very  slight  discoloration  of  the  water  objectionable,  such  as  we  practically 
find  in  all  harbors. 

Where,  particularly  in  the  lower  part  of  Manhattan,  the  sewers  are  below  high-tide 
level  and  have  a  very  flat  grade,  it  may  be  found  quite  advantageous  and  economical  to 
rebuild  such  sewers  and  to  erect  electric  pumps  so  as  to  increase  the  velocity  of  the  sew- 
age, to  keep  the  sewers  cleaner  than  they  are  now  and  to  give  the  sewage  quicker  dis- 
charge, obviating  to  a  great  extent  oxygen  exhaustion  before  entering  the  river. 

I  cannot  accept  the  Commission's  conclusion  that  the  average  oxygen  contained  in 
the  harbor  should  not  fall  below  about  58  per  cent,  of  saturation.  If  the  object  were  to 
maintain  the  life  of  major  fish  I  am  of  the  opinion  that  the  value  of  having  the  fish  in 
the  harbor  is  insignificant  when  compared  with  the  cost  of  maintaining  such  a  high 
standard  of  oxygen  saturation.  If  the  object  were  to  prevent  a  nuisance,  then  we  must 
realize  that  no  nuisance  is  caused  so  long  as  any  oxygen  remains  in  the  water.  If  this 
latter  is  the  object  of  fixing  so  high  and  therefore  so  expensive  a  standard,  I  am  of  the 
opinion  that  the  sludge  removal  in  the  harbor,  and  chiefly  from  the  localities  near  the 
sewer  outfalls,  will  tend  to  raise  the  percentage  of  dissolved  oxygen,  and  it  will  also 
tend  to  cause  the  oxygen  depletion  to  be  more  uniform  in  the  harbor  waters  than  it  is 
now,  although  the  uniformity  is  even  at  present  higher  than  might  be  expected.  The 
safety,  therefore,  of  lowering  the  permissible  percentage  of  saturation  is  correspond- 
ingly increased  before  the  probability  arises  that  at  any  locality  the  dissolved  oxygen 
might  entirely  disappear. 

There  are  a  number  of  cases  at  large  cities  where  the  percentage  is  much  lower 
than  that  proposed  for  New  York  without  causing  the  slightest  nuisance.  If  the  Lon- 
don standard  of  25  per  cent,  were  used  in  the  New  York  harbor  it  would  give  the  New 
York  waters  double  the  amount  of  oxygen  for  sewage  decomposition  than  the  standard 
proposed  by  the  Commission.  This  fact  would  postpone  for  years  the  necessity  of  build- 
ing works  for  taking  any  sewage  to  the  Lower  bay  for  oxidation  in  its  waters. 

I  consider  a  standard  of  25  per  cent,  with  frequent  sludge  removal  from  the  harbor 
bottom  a  safe  protection  against  any  nuisance  arising  from  the  water. 

I  agree  with  the  Commission  that  the  Metropolitan  area  should  be  divided  into  a 
number  of  drainage  districts,  each  of  which  requires  somewhat  different  solutions. 

I  also  agree  to  the  suggestion  that  to  carry  out  the  most  efficient  works  for  the  en- 
tire harbor  general  plans  should  be  made  by  a  central  authority  and  that  this  authority 
should  control  the  execution  of  such  plans  for  the  entire  Metropolitan  area  of  both  the 
State  of  New  York  and  the  State  of  New  Jersey. 

We  find  central  authorities  controlling  the  disposition  of  the  sewage  for  a  group 
of  communities  in  Europe,  and  also  in  our  country.  The  chief  advantage  of  such  central 
control  is  to  have  harmony  in  the  works,  to  economize  in  the  total  expenditure  and  to 
effect  a  satisfactory  disposal  for  a  distant  future  as  well  as  for  the  present  time. 

To  recapitulate : 

The  first  remedy  required,  and  one  which  you  have  proposed,  and  in  my  opinion  the 
first  one  in  importance,  is  to  intercept  all  visible  floating  sewage  matter  which  now  dis- 
gracefully covers  large  areas  of  New  York  harbor. 

The  second  remedy,  and  in  my  opinion  second  in  importance,  is  to  stop  the  further 


REPORT  OF  RUDOLPH   HERING  253 

deposition  and  putrefaction  of  sewage  sludge  on  the  bed  of  the  harbor,  chiefly  near 
sewer  outfalls,  and  in  the  meantime  to  frequently  remove  the  present  sludge  accumu- 
lations by  suction  dredging  until  sufficient  land  works  are  built  to  intercept  the  sludge 
and  prevent  excessive  amounts  from  depositing  in  the  harbor. 

The  third  important  remedy,  after  having  substantially  freed  the  harbor  from  its 
floating  matter  and  sludge,  is  to  distribute  the  sewage  thus  partially  treated  by  such  ad- 
ditional sewers  to  points  in  the  harbor  where  the  dissolved  oxygen  will  naturally  oxi- 
dize it  to  a  satisfactory  degree,  which  degree  must  be  determined  largely  and  finally  by 
actual  experience. 

The  fourth  remedy  is  to  convey  any  excessive  amounts  of  sewage  which  cannot  be 
satisfactorily  oxidized  by  the  harbor  waters  alone  to  the  nearest  and  most  suitable  areas 
on  land  for  artificial  oxidation,  as  proposed  by  the  Commission,  and  if  sufficient  land 
areas  are  no  longer  available  for  treating  all  of  the  excess,  it  would  then  be  necessary 
to  convey  this  excess  to  the  nearest  bodies  of  available  water  and  distribute  it  in  them 
so  that  it  will  get  the  required  oxidation. 

I  do  not  consider  it  necessary  to  take  the  last-mentioned  steps  at  the  present  time. 
A  better  time  than  now  to  decide  this  part  of  the  problem,  in  my  opinion,  is  after  the 
first,  second  and  third  remedies  have  been  applied,  when  it  will  be  more  practicable 
than  now  to  determine  whether  or  not  the  percentage  of  dissolved  oxygen  remaining  in 
the  harbor  waters  justified  the  expenditures  of  taking  the  excessive  amount  of  sewage 
to  the  Lower  bay. 

Rudolph  Heeing. 

December,  1913. 


CORRESPONDENCE  CONTAINING  MR.  HERING'S  ENDORSEMENT  OP  THE  COMMISSION'S  RECOM- 
MENDATION FOR  THE  GRADUAL  CONSTRUCTION  OF  THE  LOWER  EAST  RIVER  PROJECT. 

March  13,  1914. 

Rudolph  Hering,  Esq., 

170  Broadway,  New  York  City. 
Dear  Sir:  Since  your  report  of  November,  1913,  was  submitted,  some  of  the 
opinions  and  projects  relating  to  sewage  disposal  upon  which  that  report  was  based 
have  been  so  altered  in  preparation  for  this  Commission's  final  report  that  it  seems 
desirable  to  bring  the  changes  to  your  attention  and  to  ask  your  opinion  in  regard 
to  them. 

The  changes  made  affect  the  minimum  percentage  of  dissolved  oxygen  permissible 
for  the  water  and  the  Commission's  plan  for  the  protection  of  the  Lower  East  river. 
These  are  the  only  two  subjects  upon  which  you  were  not  in  substantial  accord  with 
the  Commission's  views  when  your  report  was  made. 

With  respect  to  the  oxygen  question,  this  Commission  considers  that  it  will  not 
be  necessary  to  include  a  restriction  as  to  oxygen  in  the  standard  of  cleanness  which 
should  be  established  as  a  guide  in  protecting  the  harbor  against  sewage,  for  if  the 
other  provisions  of  the  standard  are  complied  with,  there  will,  in  the  opinion  of  the 
Commission,  be  sufficient  oxygen  in  the  water  to  answer  the  requirements. 

With  respect  to  the  plan  for  the  Lower  East  river,  the  Commission  expects  to 
recommend  that  the  same  principle  of  gradual  construction  be  adopted  in  building 
the  main  drainage  and  disposal  works  which  will  be  necessary  for  the  Lower  East  river 
as  the  Commission  has  advised  in  the  projects  which  it  has  proposed  for  other  parts 
of  the  city.    Instead  of  carrying  out  the  ocean  island  project  with  its  interceptors, 


254 


REPORTS  OF  EXPERTS 


siphon,  pumping  station,  main,  island  and  settling  basin  disposal  plant  as  one  under- 
taking, only  the  first  stages  in  the  execution  of  this  comprehensive  plan  would  be 
undertaken  in  the  near  future. 

The  works  to  be  taken  in  hand  at  first  would  be,  for  Manhattan,  an  intercepting 
sewer  running  along  the  Manhattan  water  front  from  the  Battery  at  the  south  and 
26th  St.  at  the  north  to  a  point  near  Broome  St.,  where  a  screening  and  pumping 
station  would  be  located.  The  screens  would  operate  upon  the  most  efficient  principle 
for  fine  screens.  The  sewage,  after  screening,  would  be  discharged  well  out  from 
shore  at  the  bottom  of  the  river  through  multiple  outlets. 

On  the  Brooklyn  side,  the  sewage  would  be  collected  by  an  interceptor  from  Clas- 
son  Ave.  at  the  south  to  Newtown  Creek  at  the  north  to  a  point  near  South  8th  St., 
where  it  would  be  passed  through  screens  like  those  on  the  Manhattan  side  of  the  river 
and  pumped  through  submerged  outfalls  lying  on  the  river  bottom  to  a  distance  suffi- 
ciently far  from  shore  to  insure  immediate  and  thorough  diffusion. 

The  sewage  from  the  rest  of  the  Lower  East  river  territory  in  Manhattan  and 
Brooklyn  would  be  collected  for  screening  and  discharge  probably  to  as  many  points 
as  there  were  sub-divisions  or  principal  drainage  areas.  When,  after  these  works  are 
carried  out,  it  is  found  necessary  or  desirable  to  afford  further  protection  to  the 
Lower  East  river,  the  city  can  proceed  to  construct  the  siphon  to  carry  the  sewage  of 
Lower  Manhattan  beneath  the  East  river  to  the  Brooklyn  shore,  where,  after  joining 
the  sewage  from  the  screening  plant  at  South  8th  St.,  it  would  be  pumped  to  sea. 

In  the  final  development  of  this  plan,  it  will  be  necessary  to  construct  the  pump- 
ing station  on  the  Brooklyn  side,  the  main  to  the  ocean  outlet  and  the  island,  where 
the  sewage  will  be  treated  before  final  disposition.  No  part  of  the  original  construc- 
tion will  have  to  be  discarded  except  the  submerged  outfalls. 

The  Commission  believes  that  the  idea  of  proceeding  in  the  manner  indicated 
toward  the  gradual  and  ultimate  construction  of  the  ocean  island  project  may  meet 
with  your  approval,  inasmuch  as  you  consider  that  it  will  not  be  necessary  to  divert 
a  large  amount  of  sewage  from  the  Lower  East  river  and  that  screening  and  dis- 
charging the  sewage  beneath  the  deep,  strong  currents  of  the  East  river  will  per- 
manently meet  the  requirements  of  the  situation.  The  Commission  is  of  opinion  that 
the  ocean  island  project  will  be  recognized  as  a  necessity  before  many  years  and  is 
willing  to  leave  the  correctness  of  its  opinion  or  of  your  judgment  to  be  determined 
by  experience. 

If  it  never  becomes  necessary  to  build  the  siphon  between  Manhattan  and  Brook- 
lyn and  carry  the  sewage  to  a  distant  point  for  disposal,  the  stage  of  construction 
which  the  Commission  is  now  preparing  to  recommend  and  which  it  is  hoped  you  will 
approve  of  can  be  left  as  the  completed  work. 

Very  sincerely, 
(Signed)        George  A.  Soper, 

President. 

March  20,  1914. 

Metropolitan  Sewerage  Commission  op  New  York, 

Dr.  George  A.  Soper,  President, 

17  Battery  Place,  New  York  City. 

Dear  Sir  :  Your  letter  of  March  13  is  received.  Referring  in  the  same  to  my 
report  to  your  Commission  of  last  November  and  stating  that  since  then  some  opinions 
and  projects  relating  to  the  sewage  disposal  have  been  altered  by  the  Commission  in  the 


REPORT  OF  GEORGE  E.  DATESMAN 


255 


preparation  of  its  final  report,  you  desire  to  bring  these  changes  to  my  attention  and 
ask  my  opinion  in  regard  to  them. 

First:  Your  Commission  considers  that  a  restriction  as  to  the  dissolved  oxygen 
in  the  standard  of  cleanness  is  not  necessary,  because,  if  other  standard  provisions 
are  complied  with,  there  will  be  sufficient  oxygen  in  the  water  to  answer  the  require- 
ments.   You,  therefore,  omit  the  specific  restriction. 

I  am  fully  in  accord  with  this  opinion,  for  I  believe  it  would  not  only  be  imprac- 
ticable to  maintain  a  uniform  minimum  standard  for  all  parts  of  the  harbor  water 
at  all  times,  but  the  securing  of  other  conditions,  which  are  more  readily  appreciated 
by  the  population,  such  as  the  elimination  of  floating  matter  and  sludge  deposits, 
will  of  themselves  leave  sufficient  oxygen  in  solution  for  all  reasonable  requirements. 

Secondly:  With  reference  to  the  relief  of  the  Lower  East  river,  your  Commission 
applies  the  principle  of  gradual  construction  and  recommends  the  taking  in  hand  at 
first  the  building  of  certain  intercepting  sewers  along  the  Lower  East  river  both  in 
Manhattan  and  in  Brooklyn,  and  the  location  of  certain  pumping  stations  with  screens 
at  the  most  available  points,  discharging  the  sewage  well  out  from  shore  at  the  bottom 
of  the  river  through  multiple  outlets  to  insure  immediate  and  thorough  diffusion.  Your 
Commission  further  states  that  when  the  Ocean  Island  and  outlet  will  be  required  no 
part  of  the  above  construction  will  have  to  be  discarded  except  the  submerged  outfalls. 

Also  with  this  modification  of  your  views  of  last  autumn  I  am  substantially  in 
accord. 

In  order  to  increase  the  dissolved  oxygen  in  the  harbor  waters,  it  is  my  opinion 
that  not  only  the  floating  matter,  but  also  the  sludge,  should  be  retained  on  land  as 
far  as  practicable,  or  it  should  be  prevented  by  suction  dredging  from  accumulating 
anywhere  in  the  harbor. 

Regarding  the  exact  detailed  location  of  the  marginal  sewers  and  of  the  sub- 
merged outlets,  they  will  naturally  depend  entirely  upon  local  surveys,  studies  and 
estimates  of  cost.  In  general,  it  is  my  impression  that  the  outfalls  and  their  pro- 
visional positions  have  been  carefully  selected.  Although  these  detailed  investigations 
may  indicate  some  changes  or  additions,  the  principle  of  your  proposed  treatment  to 
greatly  reduce  the  present  number  of  outfalls  and  extend  the  discharge  points  well 
out  into  the  current  is,  in  my  opinion,  the  best  solution  of  the  problem. 

Very  truly  yours, 
(Signed)  Rudolph  Hering. 

SECTION  V 
REPORT  OF  GEORGE  E.  DATESMAN,  C.  E. 

To  the  President  and  Members  of 

The  Metropolitan  Sewerage  Commission  op  New  York. 

Gentlemen  :  In  accordance  with  a  request  of  your  President  that  an  examina- 
tion be  made  of  the  conditions  existing  in  the  Lower  Hudson,  Lower  East  river  and 
Bay  division  of  New  York  City  and  comparisons  be  made  of  the  projects  for  the  treat- 
ment of  this  section,  together  with  suggestions  or  recommendations  relative  thereto,  I 
have  the  honor  herewith  to  submit  a  report. 

The  inspections  made,  both  on  the  occasion  of  a  recent  visit,  covering  several  days, 
and  upon  previous  occasions,  were  confined  to  the  banks  of  the  Lower  East  river. 


256 


REPORTS  OF  EXPERTS 


They  were  made  with  a  view  of  reporting  upon  the  most  suitable  means  of  collecting 
the  sewage  along  the  river  front  and  the  merits  of  locally  placed  settling  tanks  as  com- 
pared with  screening  stations.  Various  alternative  projects  originating  with  the  Com- 
mission or  with  others  for  the  treatment  and  disposal  of  the  sewage  tributary  to  the 
Lower  East  river  were  considered. 

Present  Conditions 

The  Lower  Hudson,  Lower  East  river  and  Bay  division  comprises  the  most  pop- 
ulous portion  of  the  Boroughs  of  Manhattan  and  Brooklyn.  An  inspection  shows  that 
the  conditions  along  the  Lower  East  river  south  of  BlackwelPs  Island  make  it  difficult 
to  deal  with  this  portion  successfully.  The  area  contributing  the  sewage  includes  a 
great  number  of  high  buildings,  with  density  of  population.  Within  its  boundaries  are 
some  extensive  docks,  upon  which  are  handled  much  of  the  commerce  of  the  port.  Much 
land,  originally  marsh,  along  the  banks  has  been  reclaimed  by  the  building  of  bulk- 
heads and  filling.  Land  values,  exclusive  of  the  lofts  and  office  buildings  which  crowd 
thickly  in  this  area,  are  higer  than  in  any  other  part  of  the  city,  except  toward  the  cen- 
tral ridge  of  the  Borough  of  Manhattan.  Existing  and  proposed  subways  have  an  im- 
portant bearing  upon  the  drainage  problems. 

The  Lower  East  river  is  subject  to  tidal  flow  both  from  the  Upper  bay  and  from 
Long  Island  sound,  which,  while  giving  rise  to  currents  of  scouring  velocity,  do  not 
supply  sufficient  flow  either  from  the  bay  or  sound  to  replace  daily  the  water  that  com- 
poses the  tidal  prism,  much  less  the  volume  beneath  the  level  of  mean  low  water. 

Sewers  which  discharge  at  the  bulkhead  line  into  the  docks  and  at  the  ends  of 
piers  into  this  portion  of  the  river  contribute  an  amount  of  putrescible  matter  which, 
flowing  backward  and  forward  with  the  tide,  is  not  sufficiently  diffused  to  hide  the 
sewage  and  grease  which  deposit  in  the  slips  between  the  docks  and  elsewhere,  creating 
nuisance.  The  discharge  of  large  volumes  of  sewage  with  its  suspended  solids  tends 
to  silt  up  the  harbor  and  in  places  requires  expensive  dredging. 

From  the  progress  reports  of  your  Commision  it  appears  that  the  amount  of 
water  displaced  at  each  ebb  tide  is  but  one-eighth  of  the  volume  of  the  Lower  East  river 
below  low  water;  that  the  ratio  of  the  sewage  (contributed  from  a  population  of  up- 
wards of  2,000,000  at  present)  to  the  volume  of  water  beneath  the  level  of  mean  low 
tide  is  but  1  to  244 ;  that  the  ratio  of  this  sewage  to  the  tidal  prism  is  but  1  to  32.3 ; 
that  the  ratio  of  this  sewage  to  the  ebb  flow  is  but  1  to  5.9,  and  that  the  average  dis- 
solved oxygen  content  available  for  oxidation  of  the  organic  matter  in  the  sewage  is 
less  than  50  per  cent. 

Future  Conditions 

The  conditions  at  present,  being  such  as  to  cause  nuisance  to  sight  and  smell  and 
a  possible  menace  to  the  public  health,  will  unquestionably  become  accentuated  in  the 
future. 

The  works  projected  by  the  Commission  for  the  improvement  of  the  Harlem  sec- 
tion provide  for  the  ultimate  collection  of  about  400  million  gallons  per  day  of  sewage 
to  the  upper  end  of  Ward's  Island,  where  it  will  be  treated  in  grit  chambers  and  set- 
tling tanks  and  discharged  through  submerged  outlets  into  Hell  Gate. 

A  collecting  system  for  the  disposal  of  the  sewage  of  Newark,  Passaic  and  other 


REPORT  OF  GEORGE  E.  DATESMAN 


257 


cities  in  the  Passaic  Valley  and  its  discharge  in  the  Upper  bay  at  Robbins  Reef  is 
under  construction  by  the  Passaic  Valley  Sewerage  CommissioDers. 

From  float  experiments  made  by  your  Commission  in  the  Upper  bay  and  in  the 
East  river,  it  is  apparent  that  with  the  ebb  and  flow  of  the  tide  the  effluent  which  will 
have  to  be  disposed  of  by  dilution  at  Robbins  Reef  and  also  that  from  the  Ward's 
Island  disposal  plant  will  add  to  the  pollution  of  the  Lower  East  river.  Account 
should  also  be  taken  of  the  increasing  quantity  of  sewage  from  the  Manhattan  and 
Brooklyn  shores. 

It  is  reasonable  to  suppose  that  by  1940  there  will  be  an  increase  in  commerce,  in 
the  number  of  high  buildings  and  density  of  population,  resulting  in  an  increase  in 
sewage  pollution,  without  any  change  in  currents  or  volume  of  flow  in  the  river  which 
will  increase  its  diluting  power. 

From  calculations  published  in  your  progress  reports  it  appears  that  the  ratio  of 
sewage  to  diluting  water  in  the  East  river  in  1940,  provided  this  sewage  is  discharged 
therein,  will  be  as  follows : 


The  City  of  New  York  is  fortunate  in  that  it  is  situated  upon  one  of  the  finest 
natural  harbors  of  the  world,  and  this,  undoubtedly,  is  its  greatest  resource.  The  city 
cannot  with  impunity  neglect  the  conservation  of  this  resource  or  fail  to  provide  its 
population  with  surroundings  as  healthful  as  modern  science  will  admit. 

The  discharge  of  the  wastes  of  the  city  into  the  harbor  is  a  prodigal  waste,  for 
this  practice  discourages  commerce  and  is  in  sharp  contrast  to  the  care  with  which 
other  large  cities  guard  their  harbors. 

Boston  has  taken  the  initiative  in  the  matter  of  sewage  disposal,  having  cleaned 
up  its  waterfront  and  carried  its  sewage  a  considerable  distance  to  sea.  Whether  or 
not  this  method  of  disposal  will  always  be  regarded  as  efficient,  it  clears  the  way  for 
the  expenditure  of  large  sums  upon  its  dock  system  which  will  no  doubt  bring  results. 

Baltimore  is  about  completing  an  extensive  system  of  sewage  collection  and  dis- 
posal and  is  largely  increasing  its  dock  facilities. 

Philadelphia  is  awake  to  the  necessity  of  providing  more  adequate  means  of  sew- 
age disposal  than  exist  at  present.  It  is  adding  largely  to  its  dock  system  and  is  a  com- 
petitor for  the  commerce  which  comes  to  this  side  of  the  Atlantic. 

European  harbor  cities,  without  exception,  have  considered  the  construction  of  ade- 
quate sewage  collection  and  disposal  systems  essential  in  connection  with  their  dock 
improvements,  and  have  therefore  constructed  them. 


In  a  consideration  of  the  question  of  the  final  disposal  of  the  sewage  of  the  Lower 
East  river,  the  essential  features  are,  in  my  opinion,  as  follows: 

1.  The  removal  of  sufficient  of  the  solids  and  putrescible  matter  to  admit  of  the 
river  maintaining  itself  free  from  nuisance  to  sight,  to  smell  and  to  the  public  health. 

2.  Commercial  requirements  include  the  removal  of  floating  matter  from  the  sight 
of  those  using  the  harbor  and  the  prevention  of  undue  deposits  of  sewage  origin  or  of 
grit  which  would  silt  up  the  harbor. 


Sewage  to  volume  below  low  water 

Sewage  to  tidal  prism  

Sewage  to  ebb  flow  


1  to  132 
1  to  17.5 
1  to  3.2 


Comparison  With  Other  Cities 


Governing  Factors  for  Final  Disposal 


258 


REPORTS  OF  EXPERTS 


3.  The  system  determined  upon  must  impose  the  least  damage  to  any  locality 
with  consequent  depreciation  of  the  surrounding  territory.  There  should  he  the  least 
amount  of  nuisance  or  objectionable  conditions  created  in  special  localities. 

4.  The  waters  which  flow  out  of  the  East  river  should  not  be  so  polluted  as  to 
cause  unsatisfactory  conditions  along  the  banks  of  the  Upper  bay,  thereby  retarding 
development  in  such  sections  or  causing  depreciation  in  property  to  the  detriment  of 
the  municipality  and  individuals. 

5.  There  should  be  the  lowest  construction  cost  consistent  with  the  improvement 
needed. 

6.  There  should  be  the  lowest  maintenance  cost. 

7.  The  system  should  be  so  arranged  as  to  furnish  convenient  means  of  organizing 
the  operating  force. 

8.  There  should  be  adopted  a  system  of  collection  from  the  mouths  of  the  present 
combined  sewers  which  will  not  create  unsatisfactory  conditions  in  the  contributing 
sewers. 

9.  This  system  should  minimize  the  necessity  for  accessories  which  are  difficult 
to  operate  and  maintain. 

10.  The  works  should  provide  for  collectors  which  will  promptly  carry  the  sew- 
age to  the  points  of  treatment. 

Methods  op  Treatment  Studied  by  the  Commission 

Various  methods  of  treating  the  sewage  of  this  section  of  the  city  have  been 
studied  by  the  Commission,  among  which  may  be  mentioned  the  following : 

1.  Submerged  outlets  at  various  points  along  the  river. 

2.  "Floatation  chambers." 

3.  Grit  chambers  and  screening  stations. 

4.  Land  treatment. 

5.  Percolating  filters  and  tanks. 

6.  Locally  placed  tanks. 

7.  Removal  of  the  sewage  from  the  Lower  East  river  section  and  discharge  into 
the  Upper  bay. 

8.  Removal  of  the  sewage  to  an  island  at  sea. 

1.     SUBMERGED  OUTLETS 

By  this  plan  the  sewage  would  be  collected  by  means  of  marginal  sewers  from  the 
mouths  of  the  existing  sewer  outlets  to  convenient  points  along  both  banks  of  the 
river  and  discharged  by  submerged  outlets  into  the  channel. 

A  comprehensive  examination  of  the  river  channels,  including  that  of  the  Lower 
East  river,  made  by  your  Commission,  has  revealed  the  fact  that  the  amount  of  pol- 
lution due  to  sludge  deposits  on  the  bottom  is  considerable,  this  condition  being  most 
pronounced  in  the  docks  and  along  shores. 

The  disposal  of  raw  sewage  under  water  is  favorable  to  dispersion,  but  it  also 
favors  the  deposit  of  sludge  into  eddies  and  docks  and  along  mud  flats. 

Examinations  along  the  Manhattan  shore  of  the  Lower  East  river  at  the  mouths 
of  the  existing  sewers  have  shown  that  the  sewage,  not  being  as  saline  as  the  harbor 
water,  was  not  readily  mixed  with  the  salt  water  of  the  river,  in  consequence  of  which 
it  remained  turbid  and  undiffused  for  long  distances.   This,  however,  did  not  prevent 


REPORT  OF  GEORGE  E.  DATESMAN 


259 


the  deposit  of  solid,  gritty  and  putrescible  matter.  Therefore,  if  the  sewage  received 
no  other  treatment  than  discharge  through  submerged  outfalls,  there  would  be  no 
lessening  of  the  amount  of  material  that  would  be  deposited  and  the  amount  would  in- 
crease with  the  passage  of  years. 

It  has  been  suggested  that  when  these  sludge  deposits  form,  even  though  they  may 
not  become  a  nuisance  by  reason  of  the  depth  of  water  over  them,  they  may  be  re- 
moved by  dredging  when  concentrated  in  the  bottom  of  the  river.  Sludge  is  the  most 
difficult  material  to  dispose  of  in  connection  with  a  sewage  disposal  plant,  and  it  is 
much  more  difficult  and  expensive  to  remove  when  scattered  over  many  square  miles 
of  river  bottom. 

Such  deposits  would  injure  the  navigable  channels  of  the  harbor.  The  constant 
disturbance  of  these  deposits  by  vessels  and  the  removal  of  the  accumulations  by 
dredging  would  be  detrimental  to  commerce  and  would  probably  cause  more  nuisance 
than  the  present  method  of  disposal. 

2.     FLOATATION  CHAMBERS 

Floatation  chambers,  so-called,  would  consist  of  enlargements  of  the  mouths  of 
existing  sewers  with  properly  arranged  baffles  and  sumps  to  admit  of  the  deposit  of 
the  grit  and  the  skimming  off,  by  suitable  devices,  of  the  floating  solids. 

When  it  is  considered  that  with  this  scheme  the  sewers  would  be  subjected  to 
fluctuation  in  velocity  due  to  changes  in  the  tidal  level,  it  is  difficult  to  see  how  there 
would  be  a  sufficiently  uniform  removal  of  either  grit  or  floating  solids  to  constitute  a 
satisfactory  treatment.  Furthermore,  the  putrescible  matter  which  would  be  added 
to  the  river  would  be  but  slightly  lessened  in  amount.  Therefore,  floatation  chambers 
should  not  be  considered  as  an  adequate  system  of  final  disposal. 

3.     GRIT  CHAMBERS  WITH  SCREENS 

It  has  been  considered  that  a  sufficient  treatment  of  the  sewage  might  be  accom- 
plished by  establishing  screening  stations  at  intervals  along  the  shores,  each  station  to 
contain  grit  chambers  to  which  the  sewage  would  be  led  by  interceptors  and  pumps 
to  discharge  the  effluent  through  submerged  outlets  into  the  East  river. 

Some  examples  of  European  cities  may  be  cited  as  precedents  for  this  plan. 
Among  the  German  cities  which  have  maintained  for  some  time  and  are  successfully 
treating  their  sewage  by  means  of  grit  chambers  and  screens,  may  be  mentioned  Ham- 
burg, Frankfort  a/Main,  Diisseldorf  and  Dresden. 

At  Hamburg  the  collecting  system  is  so  arranged  that  none  of  the  sewage  escapes 
by  overflows  directly  into  the  harbor  except  when  diluted  with  at  least  four  times  its 
volume  of  storm  water.  The  Elbe  differs  from  the  harbor  conditions  at  New  York  in 
that  the  tidal  range  is  about  19  feet  and  in  the  fact  that  it  is  fresh  water.  Therefore, 
there  is  a  greater  diluting  volume  and  a  more  intimate  admixture  of  the  sewage  effluent 
with  the  harbor  water  than  would  be  the  case  in  New  York.  In  the  other  cities,  one 
upon  the  Elbe,  another  upon  the  Main  and  another  upon  the  Rhein,  the  conditions 
are  similar  to  those  at  Hamburg  as  to  the  character  of  the  water,  though  there  is  no 
tide. 

The  dilution  at  Dresden  is  much  greater  than  the  dilution  possible  in  the  Lower 
East  river  calculated  on  the  basis  of  the  tidal  prism.  The  dilution  at  Frankfort  on 
the  Main  at  times  of  low  stages  due  to  lack  of  rain  is  1  in  30 ;  at  mid-stage  1  in  1,000 ; 
high-stage,  1  in  3,000.    At  Diisseldorf  it  is  1  in  1,000  at  low  stages  of  the  river. 


260 


REPORTS  OP  EXPERTS 


One  of  the  advantages  which  is  claimed  for  screening  stations  is  that  they  require 
hut  little  land  and  therefore  would  result  in  great  saving  over  larger  though  more  effi- 
cient works. 

In  considering  the  advantage  to  be  gained  by  the  installation  of  screening  stations 
over  the  conditions  which  now  exist,  it  may  be  stated  that  the  efficiency  of  screens 
varies  from  10  to  60  per  cent,  in  the  removal  of  suspended  matter.  In  the  investigation 
made  by  your  Commission,  it  was  found  that  the  effectiveness  of  screens  was  about  20 
to  25  per  cent. 

It  has  been  shown  that  the  solids  removed  by  screens  are  largely  non-putrescible, 
and  it  is  doubtful  whether  the  resulting  benefit  to  the  river  into  which  disposal  is  made 
will  be  more  than  one-half  the  above-mentioned  percentages.  Although  probably  of 
considerable  use  in  other  parts  of  the  city,  I  do  not  think  the  benefit  to  be  gained  by 
screening  will  admit  of  this  process  being  accepted  as  a  final  and  effective  method  of 
disposal  for  the  Lower  East  river  section. 

4.     LAND  TREATMENT 

The  possibilities  of  land  treatment  for  the  sewage  of  New  York  are  admirably  dealt 
with  in  the  progress  reports  of  your  Commission.  There  is  unquestionably  not  suffi- 
cient land  available  within  reasonable  distance  to  admit  of  such  a  system  as  is  in  use 
in  Berlin  and  Paris.  Land  treatment  for  large  cities  in  England  has  in  nearly  every 
case  been  abandoned,  not  only  because  of  the  large  areas  required  and  the  expense,  but 
because  of  the  objectionable  conditions,  approaching  nuisance,  which  have  arisen  in 
connection  with  them. 

5.     PERCOLATING  FILTERS 

Percolating  filters  as  a  means  of  oxidizing  sewage  and  obtaining  an  effluent  that 
is  non-putrescible  and  therefore  fit  to  be  discharged  into  a  stream  without  nuisance 
afford  one  of  the  most  rapid  and  effective  methods  of  sewage  treatment  known. 

In  the  matter  of  precedent,  we  have  the  treatment  of  30  million  gallons  per  day 
in  Birmingham,  England;  6V2  million  gallons  in  Wilmersdorf  near  Berlin,  Germany; 
I2V2  million  gallons  in  Columbus,  Ohio;  22  million  gallons  provided  for  in  Balti- 
more, Md.,  and  various  smaller  plants  throughout  this  country  and  especially  in 
England. 

While  this  treatment  would  doubtless  afford  adequate  protection  to  the  Lower 
East  river,  there  is  no  precedent  for  a  single  plant  or  group  of  plants  that  would  take 
care  of  200  million  gallons  a  day  and  upward.  They  certainly  should  not  be  located 
in  the  occupied  portion  of  the  city. 

The  City  of  Philadelphia  is  making  careful  studies  of  the  advisability  of  install- 
ing percolating  filters  to  take  care  of  the  sewage  of  the  entire  city,  exceeding  three- 
quarters  of  a  billion  gallons,  but  in  the  absence  of  information  to  indicate  how  much 
nuisance  from  odors  and  flies  would  be  created  by  this  vast  area  of  percolating  filters, 
it  is  questionable  whether  the  scheme  will  actually  be  carried  out.  If,  as  is  done  in  some 
American  plants,  two  million  gallons  daily  can  be  treated  upon  one  acre,  it  would 
require  no  less  than  100  acres  of  filter  beds  to  treat  the  sewage  from  the  Lower  East 
river  section. 

One  of  the  progress  reports  of  your  Commision  indicates  that  there  is  no  suitable 
land  within  a  reasonable  distance  of  New  York  City  which  can  be  obtained  at  a  cheap 
enough  figure  to  make  treatment  by  filters  economical.    Unquestionably  they  would 


REPORT  OF  GEOROE  E.  DATESMAN 


261 


produce  an  inadmissible  nuisance  if  constructed  within  the  built-up  sections  of 
the  city. 

6.     LOCALLY  PLACED  TANKS 

The  plan  of  treating  the  sewage  of  the  Lower  East  river  in  settling  tanks  con- 
centrated at  one  point  would  be  open  to  the  same  objection,  lack  of  available  land,  as 
that  mentioned  for  percolating  filters. 

The  idea  of  locating  settling  tanks  along  the  shores  of  the  river  at  suitable  places, 
either  under  the  surface  of  the  streets  or  on  purchased  property  near  the  marginal 
avenues,  has  received  careful  consideration  from  your  Commission.  The  sewage, 
brought  to  the  works  by  a  system  of  interceptors,  would  be  passed  through  the  tanks 
for  a  suitable  period  of  time,  say  two  hours,  so  as  to  admit  of  the  deposition  of  the 
heavier  suspended  solids  and  a  part  of  the  putrescible  matter. 

The  results  of  my  studies  and  observations  in  Europe  and  America  compare 
favorably  with  the  deductions  as  to  the  comparative  efficiency  of  screens  and  settling 
basins  published  by  your  Commission. 

If  a  tank  of  proper  design  would  remove  in  two  hours  60  per  cent,  of  the  solids 
capable  of  settlement,  or  50  per  cent,  of  the  total  solids,  it  does  not  follow  that  the 
putrescible  matter  which  produces  nuisances  would  be  reduced  in  the  same  proportion. 
Rather  less  than  one-half  this  reduction,  or  20  to  25  per  cent.,  is  the  most  that  can  be 
expected  in  the  reduction  of  the  organic  matter,  which  is  the  material  which  has  an 
avidity  for  oxygen  and  tends  to  its  depletion. 

Tank  treatment  does  not  result  in  a  removal  of  much  of  the  discoloring  property 
of  sewage.  Consequently,  even  with  the  best  practicable  admixture  with  harbor  water, 
by  means  of  submerged  outlets,  the  presence  of  the  sewage  in  the  water  might  be  de- 
tectable by  sight. 

During  storms  the  increased  quantity  of  sewage  would  necessarily  decrease  the 
settling  period  and  consequently  increase  the  amount  of  solids  discharged  into  the 
river  with  a  consequent  effect  upon  its  color  and  turbidity.  Tank  treatment,  there- 
fore, where  applicable,  would  be  more  effective  than  screens. 

Following  is  a  concise  statement  of  the  main  argument  for  and  against  locally 
placed  settling  basins  of  various  types  as  applied  to  the  Lower  East  river  conditions. 

a.  Tanks  Placed  Under  Streets  Along  the  Lower  East  River. 

Tanks  placed  under  the  streets  would  possess  the  following  advantages  and  dis- 
advantages : 

Advantages.  The  number  of  tanks  needed  could  be  adjusted  to  the  requirements 
of  the  existing  sewer  outlets.  They  would  effect  a  saving  in  the  cost  of  interceptors. 
They  would  afford  a  convenient  means  of  disposing  of  sludge,  since  this  could  be  done 
by  pumping  to  a  barge  which  would  carry  it  to  sea. 

Disadvantages.  There  would  be  many  difficulties  of  construction.  There  would 
be  danger  from  confining  the  gases  of  putrefaction,  giving  rise  to  the  possibility  of  ex- 
plosions and  injury  to  adjacent  buildings.  The  operation  would  be  difficult,  owing  to 
the  organization  being  divided  into  many  units.  Proper  inspection  of  the  workings  of 
the  plants  would  be  difficult — a  matter  of  much  importance — since  settling  basins  must 
be  operated  properly  in  order  to  avoid  nuisance.  There  might  be  danger  to  the  health 
of  the  employees  working  under  these  unfavorable  operating  conditions.  There  would 
be  real  or  supposed  damage  to  property  and  probably  legal  injunctions  against  the 
plant  in  case  of  nuisance.    There  would  be  difficulty  in  sinking  the  caissons  for  the 


262 


REPORTS  OF  EXPERTS 


proper  construction  of  the  tanks  in  land  adjacent  to  the  river,  with  the  possibility  of 
upward  pressure  distorting  them.  There  would  be  much  interference  with  traffic 
during  construction  and  some  risk  of  interference  with  same  when  in  operation. 

b.  Tanks  Located  on  Property  Adjacent  to  Streets  for  Treatment  of  the  Combined 
Flow  of  Several  Sewers. 

Advantages.  As  compared  with  a  plan  to  take  the  sewage  to  a  distant  plant  for 
disposal,  ability  to  treat  the  sewage  near  the  point  of  production.  Saving  in  the  cost 
of  siphons,  along  outfall,  conduits  built  as  tunnels  and  expensive  terminal  works. 
Saving  in  the  amount  and  cost  of  pumping  by  taking  advantage  of  daily  low  tide  for 
discharge  of  effluent  in  part  without  pumping. 

Disadvantages.  Owing  to  the  occupation  of  all  the  land  by  buildings  on  both  the 
Manhattan  and  Brooklyn  shores,  the  cost  of  obtaining  land  at  points  near  the  river 
would  be  great.  The  land  upon  the  Manhattan  side  is  valued  at  from  $200  to  $500  per 
front  foot  of  100  feet  depth.  On  the  Brooklyn  side  it  is  valued  at  from  $100  to  $200.  The 
area  required  for  tankage  to  treat  20  to  25  million  gallons  of  sewage  per  day  is  100 
by  300  feet,  and  to  dispose  of  the  dry-weather  flow  alone,  amounting  to  upwards  of 
200  million  gallons  per  day,  would  require  no  less  than  from  8  to  10  such  units.  There 
would  have  to  be  added  to  this  the  cost  of  the  buildings  which  might  happen  to  be  on 
the  various  sites;  these  buildings  would  have  to  be  purchased  and  removed.  It  would 
be  impossible  to  utilize  the  land  over  the  tanks  for  the  construction  of  buildings  be- 
cause of  popular  prejudice,  if  not  for  reasons  of  health.  There  would  be  a  deteriora- 
tion of  the  surrounding  property  resulting  from  real  or  supposed  nuisance  created  by 
occasional  uncontrollable  conditions  of  operation. 

c.  Tanks  Removed  Several  Blocks  from  the  River. 

The  same  advantages  and  disadvantages  would  apply  to  tanks  located  some  dis- 
tance inland  as  to  tanks  placed  near  the  river  front,  and  there  would  be  the  added  dis- 
advantage of  greater  difficulty  in  disposing  of  the  sludge.  Sludge  storage  tanks 
would  have  to  be  provided ;  sludge  mains  would  have  to  be  laid ;  there  would  be  need 
of  additional  conduits  to  carry  the  effluent  from  the  tanks  to  the  point  of  final  dis- 
posal and  there  would  be  much  interference  with  traffic  during  the  construction  of 
the  works  and  the  rearrangement  of  the  underground  structures. 

TYPES  OF  TANKS 

A.   Emscher  Tanks 

Advantages.  Ability,  when  properly  operated,  to  avoid  nuisance  due  to  odors. 
Facility  with  which  the  sludge  can  be  cleaned  out.  Reduction  in  the  quantity  of 
sludge  produced. 

Disadvantages.  Difficulty  of  building  the  tanks  under  New  York  conditions.  The 
space  required :  If  placed  in  line  they  would  take  up  an  area  of  40  feet  by  340  feet  for 
the  treatment  of  12  million  gallons  per  day.  At  this  rate  Emscher  tanks  would  re- 
quire, for  the  total  output  of  203  million  gallons  per  day,  no  less  than  20  plants,  ag- 
gregating more  than  a  mile  in  length.  There  is  no  precedent  for  the  construction  of 
such  tanks  under  these  conditions.  There  would  be  great  difficulty  in  removing  the 
sludge  from  the  tanks  in  the  closely  built-up  sections  of  the  city.  Danger  of  confining 
the  gases  generated  under  street  surface,  resulting  in  possible  fire  risk  and  explosion 
and  injurious  effect  upon  employees. 


REPORT  OF  GEORGE  E.  DATESMAN 


263 


B.    Dortmund  Tanks 

Advantages.  Practically  the  same  as  with  Emscher  tanks,  except  that  there  would 
be  more  odors  produced. 

Disadvantages.  The  same  as  with  Emscher  tanks,  except  that  the  depth,  difficulty 
and  cost  of  construction  would  not  be  so  great  and  the  resulting  volume  of  sludge 
much  greater. 

C.    Plain  Sedimentation  Tanks 
Advantages.    As  compared  with  the  preceding,  they  are  nil. 

Disadvantages.  Impossibility  of  cleaning  out  the  sludge  without  removing  the 
supernatant  liquor.  Nuisance  created  while  sludging.  If  operated  with  chemicals, 
the  difficulty  in  storing,  handling  and  applying  the  chemicals.  Increase  in  amount  of 
sludge  and  putrid  condition  of  the  chemical  sludge. 

D.    Tanks  Subject  to  Tidal  Influence 
Advantages.    Saving  due  to  lack  of  necessity  for  pumping. 

Disadvantages.  Inability  to  secure  uniform  flow  and  consequently  uncertain  per- 
centage of  solids  removed  and  fluctuation  in  quality  of  effluent.  Inefficient  operation 
during  periods  of  very  high  tide.  Probability  of  silt  deposits  forming  in  the  collectors 
at  high  tide.  Inability  in  case  of  injunction  to  change  or  utilize  any  part  of  the  tank 
system  should  the  sewage  be  ultimately  carried  to  distant  points  for  disposal. 

The  use  of  submerged  outlets,  which  in  German  cities  is  considered  essential  for 
proper  dilution,  is  an  accessory  that  should  be  considered  in  connection  with  all  these 
methods  of  disposal. 

Opinion  Upon  Tank  Treatment.  The  cost  of  effecting  a  disposal  of  the  sewage  of 
the  Lower  East  river  section  by  means  of  tanks  locally  placed,  at  the  point  of  receipt 
of  the  sewage,  would  undoubtedly  be  less  expensive,  notwithstanding  heavy  land  pur- 
chases, than  the  cost  of  any  plan  to  carry  the  sewage  a  considerable  distance  away. 

Studies  made  in  Philadelphia  for  tanks  placed  under  the  surface  of  the  streets 
established  the  fact  that  while  this  principle  may  be  applied  in  isolated  cases,  it  is  not 
generally  applicable  because  of  the  large  space  required.  In  some  cases  nests  of  25 
tanks  would  take  up  the  space  under  the  streets  for  two  blocks  and  extend  over  into 
the  cross  streets,  introducing  into  the  construction  and  operation  so  many  untried  and 
uncertain  factors  that,  upon  this  ground,  and  that  of  expense  as  compared  with  the 
benefit  to  be  gained,  the  project  will  not  be  recommended. 

It  is  inadvisable  to  place  settling  basins  beneath  the  streets  of  New  York  because 
of  the  weight  of  the  disadvantages  over  the  advantages  named  and  for  the  reason  that 
the  small  benefit  that  would  accrue  to  the  river  over  present  conditions  is  negligible. 
It  is  worth  noting,  also,  that  there  would  be  a  lessening  of  the  benefit  to  be  derived 
with  the  passage  of  time. 

There  is  no  precedent  for  an  installation  of  settling  basins  of  the  size  required. 
The  experience  with  tanks,  though  satisfactory  as  at  Frankfort-on-tke-Main,  Birming- 
ham, Manchester,  London  and  elsewhere  in  England,  does  not,  in  my  opinion,  justify 
the  discharge  of  the  sewage  from  such  a  plant  into  this  section  of  the  harbor.  The 
amount  of  dilution  is  comparable  with  Birmingham  and  Manchester  only,  due  allow- 
ance being  made  for  the  different  action  of  sewage  whether  discharged  into  fresh  or 
salt  water. 


264 


REPORTS  OP  EXPERTS 


It  is  therefore  concluded  by  me  that  while  the  benefit  to  be  obtained  from  locally 
placed  settling  basins  would  be  considerable,  it  would  not  be  sufficient.  Furthermore, 
this  plan  would  not  lend  itself  to  the  development  of  any  scheme  for  carrying  the  sew- 
age to  a  distant  point  for  disposal,  so  that,  should  such  a  development  be  later  found 
advisable,  the  sums  expended  for  the  settling  basins  would  be  wasted. 

Treatment  by  passing  through  tanks  on  the  lower  end  of  Blackwells  Island  in  the 
East  river  is  open  to  the  same  objections  in  regard  to  the  pollution  of  the  Lower  East 
river  as  exist  in  regard  to  tanks  locally  placed,  although  it  would  have  the  advantage 
of  less  cost  for  the  necessary  land  upon  which  to  erect  the  plant.  This  advantage 
would  be  largely  offset  by  the  cost  of  the  siphons  to  the  island. 

7.     REMOVAL  OF  THE  SEWAGE  TO  THE  UPPER  BAY 

From  progress  reports  issued  by  your  Commission,  it  appears  that  a  study  has 
been  made  to  carry  the  sewage  to  some  point  in  the  Upper  New  York  bay  where  the  di- 
luting water  is  of  such  volume  as  to  give  a  smaller  ratio  of  sewage  to  diluting  water 
than  would  occur  in  any  other  part  of  the  inner  harbor.  The  proposition  would  be  to 
construct  an  artificial  island  immediately  south  of  Governors  Island  and,  after  treat- 
ing the  sewage  in  tanks,  discharge  the  effluent  by  submerged  outlets  into  the  main 
channel  of  the  bay. 

This  plan  would  have  the  advantage  over  locally  placed  tanks  of  eliminating  the 
high  cost  of  the  land  required  for  the  tanks  and  it  would  avoid  the  necessity  of  de- 
stroying the  existing  buildings  and  of  depreciating  surrounding  property  in  valuable 
sections  of  Manhattan  and  Brooklyn.  In  addition,  it  would  accomplish  the  entire  re- 
moval from  the  Lower  East  river  of  the  polluting  sewage  which  now  empties  therein. 
It  would  prevent  sewage  material  and  deposits  of  sludge  from  collecting  and  lying 
stagnant  in  the  docks  with  the  consequent  nuisance  to  the  public  and  to  the  com- 
mercial interests.  It  would  also  have  the  advantage  of  a  concentrated  operating  organ- 
ization. 

An  outlet  island  in  the  Upper  bay  would  have  the  disadvantage  of  being  difficult 
and  costly  to  construct  and  would  present  a  menace  to  the  cleanliness  of  the  water  in 
the  Lower  East  river,  due  to  a  tidal  flow  which  would  carry  the  effluent  from  the 
island  in  that  direction.  This  condition  would  cause  pollution  and  turbidity  of  the 
Lower  East  river  water  in  addition  to  that  which  would  be  introduced  therein  by  rea- 
son of  the  discharge  from  the  works  at  Wards  Island  to  the  north  and  from  the  Passaic 
Valley  sewer  at  Bobbins  Reef  to  the  south. 

Another  disadvantage,  and  one  of  no  mean  proportions,  would  be  in  the  creation 
of  a  popular  prejudice  against  the  development  upon  a  high  plane  of  that  portion  of 
the  Boroughs  of  Brooklyn  and  Richmond  which  lies  to  the  east  and  south  of  the  site 
of  the  works.  This  might  result  in  a  great  depreciation  of  land  values  and,  by  reason 
of  an  occasional  concentration  of  the  effluent  from  the  sewage  works,  become  a  source  of 
nuisance  to  future  inhabitants  of  this  territory,  resulting  in  stagnating  the  growth  of 
these  portions  of  the  city.  It  might  become  a  matter  of  policy,  due  to  increase  in  pop- 
ulation and  of  the  amount  of  sewage  furnished  to  the  Wards  Island  works,  to  carry 
a  certain  proportion  of  the  sewage  which  would  ultimately  be  collected  at  Wards 
Island  to  the  island  below  Governors  Island  for  disposal.  If  this  were  done  there 
would  be  a  cumulative  objection  against  this  point  of  disposal. 

In  addition,  such  unsettled  materials  as  might  be  discharged  with  the  effluent 
might  aid  in  silting  up  the  channel,  requiring  costly  dredging. 


REPORT  OP  GEORGE  E.  DATESMAN 


265 


Furthermore,  the  turbidity  of  the  water  in  the  Upper  bay  would  be  such  as  to  af- 
ford ground  for  unfavorable  comment,  on  the  part  of  persons  on  incoming  and  out- 
going vessels  and  among  those  who  cross  the  harbor  daily,  as  to  the  sanitary  facilities 
provided  by  New  York.  The  works  themselves  might  not  be  free  from  objectionable 
characteristics.  It  therefore  appears  that  by  this  scheme  the  city  would  be  unable  to 
rid  itself  of  the  visible  presence  of  sewage  and  the  odors  arising  therefrom. 

The  cost  of  works  of  this  kind  would  be  materially  less  than  some  of  those  pro- 
posed, comparing  favorably  on  this  score  with  the  scheme  for  locally  placed  tanks,  but  it 
would  be  much  greater  than  the  latter  in  the  betterment  which  would  be  afforded  to 
the  Lower  East  river. 

8.     REMOVAL  OF  THE  SEWAGE  TO  AN  ISLAND  AT  SEA 

In  comparing  the  studies  for  the  various  methods,  there  appears  to  be  an  advan- 
tage in  removing  the  sewage  a  long  distance  from  the  point  of  production. 

I  am  strongly  impressed  that  it  is  desirable  to  carry  the  sewage  to  a  point  where 
the  disadvantages  which  apply  to  the  Governor's  Island  site  can  be  eliminated,  because 
this  would  protect  the  interests  of  all  localities  of  the  city  in  the  matter  of  real  estate 
development  and,  for  all  time,  remove,  without  possibility  of  pollution,  all  the  sew- 
age from  the  concentrated  area  adjacent  to  the  LoAver  East  river,  thereby  relieving 
this  river  and  contiguous  parts  of  the  harbor  of  the  burden  of  oxidizing  the  sewage. 

The  amounts  of  sewage  effluent  which  would  be  discharged  at  Ward's  Island  and 
at  Robbins  Reef  are  reasonably  well  known,  therefore  it  should  not  be  difficult  to  in- 
sure for  this  portion  of  the  harbor  a  dilution  which  would  be  sufficient  to  avoid  nui- 
sance, turbidity,  greasy  slime  or  the  deposit  of  such  silt  as  may  come  from  the  streets. 

The  advantage  of  carrying  the  Lower  East  river  sewage  to  a  distant  point  for  dis- 
posal is  that  all  the  objectionable  features,  except  that  of  expense,  which  are  apparent 
against  the  various  other  schemes  mentioned  separately  or  collectively,  would  be  elim- 
inated. The  cost  should  not  prevent  the  accomplishment  of  the  desired  object. 

The  relation  which  the  City  of  New  York  bears  to  the  other  cities  of  the  world  is 
unique.  Its  growth  has  been  so  rapid  that  it  is  not  unreasonable  to  predict  that  even 
at  the  time  provided  for  by  your  Commission,  namely,  1940  to  1950,  it  will  be  the  lead- 
ing city  in  the  world  in  wealth  and  population. 

As  other  cities  with  great  harbors  have  recognized  the  importance  of  a  sanitary 
treatment  of  their  sewage  as  the  one  essential  accompanying  the  construction  of  a 
great  dock  system,  it  is  apparent  that  the  City  of  New  York,  to  maintain  its  commercial 
and  metropolitan  leadership,  must  not  be  satisfied  with  any  scheme  of  sewage  disposal, 
the  success  of  which  is  doubtful. 

The  difference  in  expense  between  a  plan  of  sewage  disposal  which  is  experimental 
or  temporary  and  one  which  can  confidently  be  expected  to  be  satisfactory  should  not 
be  controlling  when  works  are  contemplated  which  are  to  last  through  the  present 
century. 

The  Commission's  Project 

Your  Commission,  after  a  careful  study  of  details  and  a  comparison  of  existing 
conditions  elsewhere,  has  arranged  a  comprehensive  scheme  which  is  well  adapted  to 
the  situation.  Although  collectively  monumental,  there  is  ample  precedent  for  each 
part. 


266 


REPORTS  OF  EXPERTS 


Briefly,  this  scheme  consists  of  carrying  the  sewage,  which  now  collects  and  de- 
posits in  the  docks,  to  convenient  points  along  the  marginal  avenues  and  then  convey- 
ing it  by  deep  collectors  and  an  inverted  siphon  under  the  Lower  East  river  to  some 
point  upon  the  Brooklyn  side,  where  it  would  be  pumped  through  a  conduit  built  in 
tunnel  through  the  high  land  of  southwestern  Brooklyn  under  Coney  Island  and  the  sea 
to  an  island  about  3y2  miles  off  the  shore.  The  total  length  of  the  conduit  beyond  the 
pumping  station  would  be  about  13  miles. 

The  construction  of  interceptors  to  collect  the  sewage  from  the  sewerage  systems 
which  now  pollute  the  river  fronts  is  a  standard  practice  both  in  American  and  Euro- 
pean cities. 

The  building  of  the  deep  conduits  and  the  siphon  under  the  river  have  their 
precedents  in  the  remarkable  success  which  has  heretofore  been  achieved  in  the  City 
of  New  York  in  the  matter  of  tunnel  construction  over  that  of  any  other  city  in  the 
world.  The  improvement  in  tunneling  machinery,  by  reason  of  the  impetus  given  it, 
will  facilitate  such  construction  and  enable  engineers  to  estimate  very  closely  upon 
the  length  of  time  required  and  cost  of  construction. 

The  design  of  recent  pumping  machinery  is  undergoing  some  revolutionary 
changes.  The  use  of  oil  for  fuel  has  cheapened  this  work  and  recently  there  has  been 
installed  pumps  upon  the  explosion  principle  which  show  great  economies. 

It  is  reasonable  to  suppose  that  even  greater  improvements  will  be  made  within 
the  next  few  years,  so  that  the  matter  of  pumping  200  million  gallons  of  sewage  daily 
will  be  accomplished  at  a  comparatively  low  cost  and  with  no  great  difficulty. 

The  site  for  the  proposed  island  has  been  chosen  upon  a  natural  reef  flanked  on  all 
sides  by  deep  channels  and  ocean  currents.  As  the  reef  has  withstood  the  storms  of 
many  years  and,  from  information  obtained,  has  remained  unchanged  for  the  greater 
part  of  a  century,  conclusive  proof  is  afforded  that  the  foundation  for  the  proposed 
island  will  be  durable. 

Disposal  at  this  location  has  all  the  advantages  which  have  been  mentioned  for 
the  other  schemes,  individually  and  collectively,  except  as  to  expense.  In  addition,  it 
entirely  avoids  danger  of  nuisance  and  depreciation  of  any  of  the  property  within 
Greater  New  York,  as  far  as  the  sewage  from  the  Lower  East  river  is  concerned. 

Float  experiments,  carried  on  over  a  whole  season,  indicate  unquestionably  that 
the  effluent  which  would  be  discharged  at  this  island  would  never  reach  the  entrance 
to  the  Narrows  nor  menace  the  pleasure  beaches  at  Coney  Island  and  Rockaway. 

For  the  construction  of  this  sea  island  there  is  no  precedent  in  sewage  disposal 
works.  Similar  constructions,  however,  have  been  made  in  New  York,  and  many  per- 
manent structures  have  been  erected  in  connection  with  harbors  and  fortifications  in 
other  cities  of  the  world  having  open  harbors.  The  methods  to  be  applied  are  well 
known  and  do  not  present  any  insdrmountable  difficulties.  The  island  would  be  as 
capable  of  resisting  the  onslaughts  of  storms  from  the  open  ocean  as  would  a  break- 
water at  the  mouth  of  a  harbor. 

The  system  of  treatment,  after  the  sewage  reaches  the  island,  would  be  by  means 
of  settling  tanks,  the  grit  and  large  solids  having  been  extracted  in  grit  chambers 
and  screens  at  the  pumping  stations  or,  if  desired,  elsewhere  along  the  line  of  the  main 
collecting  sewers. 

The  discharge  of  the  effluent  from  settling  tanks  through  submerged  outlets  into 
the  waters  about  the  island  would  be  favorable  for  diffusion  at  all  stages  of  the  tide. 
The  currents  would  serve  to  distribute  it  and  to  increase  the  diluting  volume. 


REPORT  OF  GEORGE  E.  DATESMAN 


267 


The  disposition  of  the  sludge  would  be  simple.  The  proximity  of  the  open  ocean 
would  enable  sludge  steamers  to  carry  it  to  sea,  finding  there  such  a  dumping  ground 
as  would  prevent  the  return  of  any  material  to  the  shores. 

The  Principle  of  Gradual  Construction 

The  island  scheme  is  flexible  and  extensible  and  I  agree  that  it  should  be  carried 
out  in  progressive  stages.  Should  the  amount  of  sewage  which  ultimately  reaches 
Wards  Island  be  such  as  to  cause  undue  turbidity  in  the  waters  of  the  Lower  East 
river  or  along  Long  Island  Sound,  it  would  be  practicable  to  carry  the  sewage  by  tun- 
nel from  Wards  Island  to  the  junction  with  the  proposed  outlet  tunnel  or  to  con- 
struct a  duplicate  tunnel  to  the  island  for  the  disposition  of  this  seAvage. 

Progressive  Steps.  The  island  plan  of  disposal  lends  itself  readily  to  progressive 
construction  and  the  steps  which  you  have  indicated  appear  to  me  to  be  the  proper 
ones  to  take.  The  first  step  should  consist  of  the  construction  of  the  interceptors, 
which  are  essential  in  any  case.  The  sewage,  until  such  time  as  the  East  river  becomes 
overtaxed,  should  be  collected  at  one  or  more  suitable  stations  upon  both  shores  of 
the  East  river,  passed  through  screening  stations  and  pumped  through  multiple  sub- 
merged outlets.   This  would  relieve  the  worst  of  the  present  insanitary  conditions. 

Precedent  for  the  operation  of  screening  stations  for  a  population  equal  to  that 
to  be  served  in  this  portion  of  New  York  City  without  nuisance  exists  in  the  city  of 
Hamburg,  Germany,  where  there  is  placed  upon  a  marginal  avenue  corresponding 
with  West  street,  adjacent  to  docks  corresponding  to  those  of  the  East  river  and  im- 
mediately across  the  avenue  from  the  State  Nautical  School,  a  screening  station  for  a 
population  of  about  800,000  and  another  station  for  200,000  in  the  midst  of  the 
warehouse  district. 

Inasmuch  as  the  water  of  the  East  river,  as  regards  dissolved  oxygen,  would  not 
be  appreciably  improved,  I  am  of  opinion  that  this  treatment  would  be  warranted  for 
a  time  only,  or  during  the  construction  of  the  deep,  connecting  interceptors  and  the 
siphon  under  the  river,  together  with  the  deep  tunnel  to  the  site  of  the  island,  or  until 
such  time  as  the  extent  of  the  relief  required  in  the  Lower  East  river  was  recognized 
as  greater  than  could  possibly  be  afforded  by  the  use  of  screen  stations. 

The  submerged  outlets  could  be  abandoned,  or  even  the  screen  stations  could  be 
eliminated  with  comparatively  little  loss,  in  view  of  the  small  area  required  for  the 
latter  and  the  ability  to  utilize  the  pumps  in  the  pumping  station  to  be  located  else- 
where. It  is  readily  seen  that  the  project  of  establishing  screening  stations  lends  itself 
as  a  step  in  the  accomplishment  of  the  greater  scheme. 

The  next  step  would  be  to  combine  the  Manhattan  and  Brooklyn  sewage  by 
siphon  and  pump  it  to  sea,  discharging  it  through  a  crib*  freely  into  the  waters  of  the 
ocean.  The  crib  construction  could  be  used  as  the  nucleus  about  which  the  island 
would  be  built  later. 

The  third  step  would  be  the  construction  of  the  island  and  the  building  of  the 
settling  tanks  with  submerged  outlets  for  the  effluent. 

Should  it  be  practicable  to  accomplish  the  results  aimed  at  both  in  the  removal 
of  the  sewage  from  the  Lower  East  river  and  the  prevention  of  the  return  of  sewage 
matter  to  the  shores  adjacent  to  New  York  City  by  the  crib  project  without  the  use  of  the 
island,  the  construction  of  the  island  might  be  indefinitely  delayed. 

*This  step  is  not  recommended  by  the  Commission.   For  details  of  proposed  plan,  see  Part  II,  Chap.  VI,  p.  99. 


268  REPORTS  OF  EXPERTS 


With  the  foregoing  principles  and  plans  of  your  Commission  I  am  in  full  agree- 
ment. All  the  essential  features  are  in  accordance  with  well-established  engineering 
practice. 

Precedent  fob  Removal  of  Sewage  to  a  Distance  for  Treatment 

There  is  ample  precedent  for  the  removal  of  sewage  to  a  considerable  distance  for 
disposal,  as  the  following  examples  show : 

Berlin.  In  the  city  of  Berlin  there  have  been  established  twelve  pumping  dis- 
tricts, to  each  of  which  a  certain  proportion  of  the  sewage  of  the  city  is  conducted,  and 
from  which  the  sewage  is  pumped  to  works  consisting  of  irrigation  farms,  through 
force  mains,  in  a  number  of  cases  10  miles  long  and  in  two  cases  15  miles  long.  One  of 
the  twelve  pumping  stations  has  a  daily  capacity  of  about  75%  million  gallons.  Sev- 
eral of  the  larger  pumping  stations  collectively  have  a  capacity  greater  than  that  re- 
quired for  the  Lower  East  river  sewage. 

Paris.  The  whole  of  the  drainage  of  Paris  is  prevented  from  reaching  the  Seine 
within  the  city  limits  by  means  of  interceptors  and  is  carried  through  an  outfall  con- 
duit to  a  distance  of  17  miles  from  the  westerly  boundery  of  the  city.  The  sewage  is 
applied  to  sewage  farms.  It  is  anticipated  that  within  the  near  future  a  more  modern 
method  of  sewage  disposal  will  be  projected  and  later  installed. 

London.  The  sewage  of  London  is  intercepted  by  high-level  interceptors,  where 
practicable,  and  carried  by  gravity  to  works  at  Barking,  situated  on  the  north  side  of 
the  Thames,  a  distance  of  I2V2  miles  from  the  center  of  the  city.  On  the  south  side  it 
is  collected  at  Crossness,  14  miles  from  the  center  of  the  city. 

Other  interceptors  along  the  Thames  collect  the  low-level  sewage  and  this  is 
pumped  to  the  high-level  interceptors.  This  system  has  been  successful  in  removing  the 
pollution  formerly  existing  along  the  banks  and  in  the  docks  of  the  harbor,  making 
conditions  about  the  parliament  and  other  public  buildings  objectionable. 

The  treatment  of  the  sewage  is  by  tankage,  chemical  precipitation  and  discharge 
during  ebb  tide. 

Philadelphia.  The  project  for  the  collection  of  the  sewage  from  the  extensive  area 
within  the  City  of  Philadelphia  includes,  as  far  as  decided  upon,  the  carrying  of  the 
sewage  to  two  points  for  disposal.  The  more  remote  of  these  will  require  the  construc- 
tion of  collectors,  which,  with  the  contributing  sewers,  will  cause  the  sewage  to  travel 
12  miles. 

Features  of  Design 

The  methods  available  for  collecting  the  sewage  from  the  Lower  East  river  section 
of  the  division  under  discussion  are  various.  The  use  of  collecting  sewers  is  essential 
and  their  locations  and  types  are  matters  to  which  you  have  given  much  study.  You 
have  prepared  many  alternative  projects,  including  interceptors  at  high  and  low 
levels,  near  and  remote  from  the  waterfront,  deep-lying  and  near  the  surface  of  the 
ground  and  with  and  without  regulators  and  tide-gates.  It  is  unnecessary  to  describe 
these  plans  here,  but  I  will  discuss  the  topic  of  collectors  from  my  own  point  of  view. 

The  highest  efficiency  in  any  collecting  system  is  accomplished  when  the  mini- 
mum of  pumping  is  required,  both  as  to  quantity  and  lift. 

The  choice  between  a  high-level  system,  which  would  avoid  pumping,  and  a  low- 
level  system,  requiring  pumping,  or  a  combination  of  both,  is  made  upon  the  well- 


REPORT  OF  GEORGE  E.  DATESMAN 


269 


known  rule  that  pumping  should  be  avoided  wherever  possible,  even  at  the  sacrifice  of 
some  of  the  results  which  are  desirable. 

Where,  by  reason  of  the  advisability  of  rebuilding  sewers  on  the  separate  plan 
within  the  area  served  by  a  low-level  intercepting  system,  the  use  of  the  high-level  sys- 
tem is  thought  inadvisable,  there  is  usually  some  practicable  mean  where  the  low  level 
may  be  in  part  converted  to  a  high  level,  thereby  lessening  the  amount  of  pumping  re- 
quired and  the  area  over  which  it  is  necessary  to  rebuild  the  system. 

In  my  examination  of  the  collecting  systems  I  was  impressed  by  the  fact  that, 
especially  in  the  German  cities,  the  interceptors  had  been  planned  and  were  operating 
more  economically  than  is  the  case  in  the  usual  American  city.  In  fact,  I  know  of  no 
case  in  this  country  where  the  same  principles  have  been  followed. 

High-  and  Low-Level  Interceptors 

It  might  be  proposed  to  carry  a  high-level  interceptor  by  deep  tunnel  close  to  the 
ridge  of  Manhattan  Borough  and  a  similar  sewer  a  considerable  distance  away  from 
the  river  upon  the  Brooklyn  side.  The  advantage  would  be  that  these  interceptors 
could  be  built  without  interfering  with  traffic,  subways  or  underground  structures. 
Owing  to  the  fact  that  a  majority  of  the  sewers  in  the  areas  of  lower  Manhattan  and 
Brooklyn  are  subject  to  tidal  influence  for  a  considerable  distance  from  their  outlets, 
the  construction  of  such  high-level  interceptors  would  leave  extensive  areas  in  which 
there  probably  would  be  required  the  reconstruction  of  existing  storm  sewers  and  the 
addition  of  the  sewers  which  would  collect  the  house  drainage  to  low  points,  where  it 
could  be  pumped  into  the  high-level  interceptors. 

The  difficulty  of  the  latter  construction,  due  to  interference  with  traffic,  the  net- 
work of  underground  structures,  the  cutting  up  of  the  district  by  proposed  subways 
and  the  cost  of  requiring  alterations  in  the  plumbing  of  many  houses,  added  to  the 
large  cost  of  repaving  the  streets,  would  appear  to  make  the  approval  of  this  proposi- 
tion inadvisable. 

The  placing  of  interceptors  along  the  marginal  avenues  crossing  under  the  in- 
verts of  the  existing  outlet  sewers  would  avoid  reconstruction  and  the  introduction  of 
the  double  system  of  sewers  in  a  large  territory,  but  would  be  attended  with  the  diffi- 
culty found  in  deep  foundation  work  and  would  probably  require  the  use  of  compressed 
air  at  considerable  cost.  It  would  add  to  the  pumping  cost  and  maintenance,  would 
require  the  use  of  regulators  and  tide-gates,  all  of  which  are  more  or  less  unreliable  in 
their  action,  and  would  require  constant  maintenance. 

Connections  With  Interceptors 

A  method  of  designing  interceptors,  which  may  be  discussed  in  relation  to  the  New 
York  project,  is  the  system  which  has  been  practiced  in  most  of  the  European  cities, 
notably  those  in  Germany,  consisting  of  a  conduit  across  the  mouths  of  the  existing 
outlets  entirely  excluding  the  sewage  collected  therein  from  the  harbors  or  streams. 

This  system  has  the  disadvantage  of  requiring  larger  cross-sections  for  the  sewers, 
but,  on  the  other  hand,  the  increased  size,  allowing  flatter  grades,  would  save  in  the 
depth  to  which  the  construction  would  otherwise  be  carried. 

The  system  involves  placing,  at  intervals,  overflow  dams  with  storm-water  con- 
duits to  the  river  so  that  when  the  flow  is  collected  from  a  number  of  sewers,  to  which 
has  been  added  storm  water  from  3  to  6  times  the  dry-weather  flow,  the  diluted  sew- 
age overflows  the  dams  and  reaches  the  harbor. 


270 


REPORTS  OF  EXPERTS 


The  only  regulators  which  would  be  required  under  this  system  are  the  dams  them- 
selves, automatic  tide-gates  being  unnecessary,  except  as  in  the  case  of  Hamburg, 
where,  by  reason  of  large  tidal  range,  the  sewers  are  called  upon  to  act  as  a  reservoir 
for  a  part  of  the  time. 

The  elimination  of  moving  part  regulators  and  tide-gates  are  matters  to  be  care- 
fully weighed,  as  their  use  is  unreliable  and  would  tend  to  increase  the  operating  cost 
and  possibly  at  times  overtax  the  pumping  stations. 

A  system  which  is  a  modification  of  the  principles  in  use  abroad,  which  would 
admit  of  considerable  saving  over  the  usually  applied  American  system,  has  been  de- 
veloped in  the  case  of  the  collectors  at  Philadelphia. 

It  has  been  found  economical  to  build  both  high-  and  low-level  sewers,  carrying 
every  cubic  foot  of  sewage  practicable  by  gravity  to  the  treatment  works.  In  the  low- 
level  system,  by  substituting  a  dam  to  exclude  tide  water  in  the  combined  sewer  at 
such  a  point  removed  from  the  outet  that  the  crest  will  not  rise  beyond  two-thirds  of  its 
vertical  diameter,  large  tide-gates  at  the  outlets  may  be  eliminated.  Thus  to  the  ad- 
vantage due  to  grade  in  the  sewer,  saved  in  the  depth  of  the  main  collector,  is  added 
the  advantage  of  carrying  the  interceptor  through  the  dam,  resulting,  in  some  cases, 
in  raising  the  whole  length  of  the  interceptor  from  6  to  10  feet  over  its  position  in 
the  usual  American  plan.  This,  of  course,  involves  the  construction  of  a  system  of  do- 
mestic-sewage sewers  in  streets  tributary  to  the  main  combined  sewer  below  the  dam 
and  the  making  of  new  house  connections. 

The  effect  is  to  leave  open  to  tidal  fluctuation  that  portion  of  the  combined  sewer 
between  the  dam  and  oulet.  If  the  sewage  is  carried  away  from  a  river,  even  the  tide- 
locking  of  this  portion  of  the  sewer  should  not  be  a  detriment  to  the  intercepting 
sewers,  which  are  not  affected  thereby  in  a  pumping  system. 

The  benefit  in  the  item  of  cost  of  a  long  interceptor,  by  being  able  to  raise  it  from 
6  to  10  feet,  is  apparent ;  also  the  saving  due  to  decreased  lift  at  pumping  stations. 

Where  grades  of  combined  sewers  admit,  additional  savings  may  be  made  in 
depth  of  interceptors  by  placing  them  at  some  distance  from  the  marginal  avenue. 
This  should,  however,  always  permit  of  a  house-sewage  sewer,  when  running  against 
grade,  reaching  the  interceptor. 

Another  accessory  of  this  plan  is  the  introduction  of  overflow  chambers  of  en- 
larged section  to  admit  of  carrying  off  the  storm  flow  into  the  conduit  below,  wherever 
the  dams  are  introduced. 

In  Philadelphia  it  has  been  planned  to  introduce  such  dams,  even  in  low-lying 
areas  where  tidal  influence  extends  between  4,000  and  8,000  feet  from  the  outlets.  The 
dams  will  be  placed  at  about  2,500  feet  inland  from  the  river,  involving  the  building 
of  a  separate  system  of  sewers  in  the  territory  below  the  dams  and  carrying  of  the 
drainage  back  to  the  main  collector.  Light  grades  may  be  used  on  the  small  sewers, 
which  may  be  flushed  at  high  tide  from  the  river,  either  automatically  or  by  hand- 
operated  gates. 

Suggestions  Applicable  to  New  York 

The  placing  of  such  interceptors  as  have  been  described  along  the  Lower  East 
river  in  both  Manhattan  and  Brooklyn  Boroughs  would,  in  my  judgment,  result  in 
economies  in  first  cost;  would  reduce  to  a  minimum  the  area  that  would  be  required  to 
be  sewered  upon  the  double  system  and,  if  placed  generally  about  two  blocks  back  from 
the  river,  would  interfere  less  with  the  traffic;  would  admit  of  the  house  drainage 


REPORT  OF  GEORGE  E.  DATESMAN 


271 


from  the  river  front  being  carried  backward  for  these  two  blocks  into  the  main  inter- 
ceptors; would  gain  considerable  from  the  depth,  due  to  the  grade  of  the  existing 
sewers;  would  proportionately  lessen  the  lift  required  of  the  pumps,  and  would  raise 
the  head  upon  any  siphon  which  would  be  put  in  the  final  scheme  for  disposal  at  a  dis- 
tance, thereby  lessening  the  lift  for  pumping  and  consequent  cost  for  all  time. 

As  to  precedent,  it  may  be  mentioned  that  Hamburg  has  a  tidal  range  of  5.8 
meters.  This  city,  especially  along  the  routes  of  the  main  interceptors,  is  intersected 
by  canals  and  is,  therefore,  very  flat.  Notwithstanding  this  fact,  the  interceptors  carry 
across  the  mouths  of  the  combined  sewers,  overflows  for  storm  water  being  secured  at 
convenient  intervals  by  the  water  rising  above  the  dams  fixed  to  carry  to  the  works 
several  times  the  dry-weather  flow.  By  means  of  tide-gates  upon  storm  overflows,  the 
harbor  water  is  excluded,  the  conduits  discharge  when  the  tides  are  favorable,  the  sys- 
tem acting  as  a  reservoir  when  they  are  unfavorable.  Cleansing  velocities  are  obtained 
at  low  stages  of  the  tide.  As  this  is  a  screening  system,  the  fluctuation  of  flow  is  not 
material. 

If,  therefore,  a  low-lying  city  like  Hamburg  can  discharge  from  combined  sewers 
through  collectors  whose  inverts  are  below  sea  level  without  resorting  to  pumping, 
as  is  the  case  in  the  north  side  station,  it  may  be  practicable  by  study  of  the  New  York 
marginal  collectors  with  a  certain  amount  of  reconstruction  of  the  local  sewers  to  ac- 
complish equally  good  results. 

In  some  cases,  at  least,  pumping  may  be  lessened,  especially  if  the  proposed  tem- 
porary screen  stations  are  installed  on  the  banks  of  the  Lower  East  river. 

While  Hamburg  is  most  analogous  to  New  York,  with  the  advantages  of  topog- 
raphy in  favor  of  the  latter,  the  same  general  scheme  is  carried  out  in  other  Euro- 
pean cities  where  tidal  conditions  do  not  prevail,  but  where  flood  water  heights  in  the 
rivers  must  be  contended  with,  notably  at  Leipzig,  Dresden,  Frankfurt  a/Main, 
Munich,  Vienna  and  Paris. 

The  types  of  interceptors  are  such  as  to  provide  proper  sectional  area  in  the  in- 
verts for  dry-weather  flow,  with  additional  provision  for  collecting  the  storm  water  from 
the  combined  sewers  and  carrying  it  to  suitable  places  for  discharge.  The  dams  used 
are  placed  at  about  or  above  the  springing  line  of  the  interceptors,  the  flat-section  storm 
conduits  discharging  without  tide-gates  in  most  cases,  the  invert  of  the  interceptor 
being  under  the  low-water  stages,  or,  as  in  the  case  of  Hamburg,  under  the  sea  level. 

In  an  examination  of  the  profiles  of  collectors  along  the  Manhattan  and  Brooklyn 
banks  of  the  Lower  East  river  section,  as  published  in  Preliminary  Report  VI  of  your 
Commission,  it  appears  to  the  writer  that,  notwithstanding  the  statement  that  the 
sewers  are  in  many  cases  tide-locked  at  high  tide,  the  elevations  of  the  existing  sewer 
outlets  lend  themselves  to  a  collecting  system  similar  to  that  just  described.  The 
feasibility  of  this,  however,  is  dependent  upon  there  being  a  considerable  fall  in  the 
tributary  outfall  sewers  toward  the  river.  Should  examination  prove  the  practicability 
of  this  plan,  the  interceptors  should  be  built  with  falls  generally  as  shown  upon  your 
diagrams,  but  at  an  elevation  which  would  place  them  directly  across  or  slightly  below 
the  mouths  of  the  existing  sewers  and  bring  the  sewage  to  the  proposed  screen  stations 
at  such  elevations  as  to  permit  of  discharge  through  screens  with  a  minimum  pumping 
lift.  This  of  necessity  would  require  storm  overflows  without  tide-gates,  in  some  cases 
the  present  outfalls  being  utilized;  in  others  conduits  one  or  two  blocks  long  being 
specially  constructed. 

This  system  would  require  a  considerably  larger  cross-section  than  has  been 


272 


REPORTS  OF  EXPERTS 


planned,  but  would  avoid  tide-gates  and  would  gain  possibly  one-half  of  the  total  depth 
as  planned,  thereby  admitting  of  open-cut  construction  without  the  use  of  compressed 
air  tunneling  methods.  It  would  be  somewhat  objectionable  on  account  of  inter- 
ference with  traffic. 

The  tidal  circulation  through  the  system  would  continue  the  present  condition  of 
fluctuating  velocities,  but  this  would  be  compensated  for  by  the  saving  in  cost  of  smaller 
pumping  stations,  especially  if  they  were  temporary,  and  could  later  be  abandoned. 

If  tidal  flow  through  the  collectors  is  considered  inadvisable,  sewers  of  the  same 
sizes  as  those  projected  could  be  placed  at  elevations  possibly  one-half  the  depth  of 
those  shown  upon  your  plans,  especially  if  they  are  placed  along  avenues,  say  two 
blocks  from  the  marginal  streets,  or  about  midway  between  the  river  and  the  limit  of 
tidal  influence.  These  sewers  could  deliver  the  sewage  at  an  elevation  requiring  pump- 
ing for  a  portion  of  each  tide  only. 

But  a  comparatively  small  area  would  require  to  be  supplied  with  house  sewage 
sewers,  say  two  blocks,  the  drainage  being  carried  by  gravity  into  the  main  collectors. 

It  would  also  lend  itself  admirably  to  the  final  disposition  at  the  ocean  outlet 
island  and  would  save  the  capitalized  cost  of  lifting,  by  pumps,  200  m.g.d.  through 
the  number  of  feet  saved  in  the  depth  of  the  interceptor. 

The  former  scheme  would  require  no  regulators  except  overflows,  but  would  not 
divide  the  sewage  from  storm  water  as  well  as  the  latter,  until  the  installation  of  the 
pumping  station  to  the  island. 

Should  the  latter  installation  be  found  feasible  it  would  involve  the  construction 
of  dams  in  the  storm  sewers,  with  overflow  chambers,  and  regulators  to  intercept  a  cer- 
tain amount  of  sewage  during  storms,  especially  after  the  introduction  of  the  pumping 
station  to  the  sea  island. 

I  am,  therefore,  reasonably  sure  that  a  higher  low-level  collecting  sewer  than  the 
one  you  have  planned  would  be  feasible,  not  only  for  this  section,  but  in  other  marginal 
sections,  at  a  great  aggregate  saving  in  construction  cost.  This  would,  in  my  opinion, 
result  in  a  considerable  reduction  in  the  capitalized  cost  of  operation,  thereby  strength- 
ening the  argument  in  favor  of  your  comprehensive  scheme  of  disposal  for  this  division. 

Conclusion 

After  a  careful  consideration  of  the  various  projects  discussed  in  this  report  for 
the  collection  and  disposal  of  the  sewage  from  the  Lower  East  river  section,  I  am  of 
the  opinion  that  the  use  of  collectors  is  essential  for  any  satisfactory  system  of  disposal. 

Locally  placed  settling  tanks  as  a  final  means  of  disposal,  while  they  may  be  con- 
structed at  less  cost  than  the  other  suggested  schemes,  would  not  afford  sufficient  re- 
lief to  the  Lower  East  river  to  make  their  installation  a  lasting  benefit.  This  is  not 
intended  to  discourage  their  use  where  the  volume  of  dilution  is  sufficiently  great  and 
the  immediate  land  surroundings  are  suitable. 

If  used,  the  settling  tanks  should  be  of  a  form  from  which  the  deposits  can  be  re- 
moved without  throwing  the  tank  out  of  service.  A  Dortmund  tank  or  an  Emscher 
tank  would  fulfil  this  requirement. 

The  use  of  grit  chambers  and  screening  stations,  while  not  as  effective  as  tank 

treatment,  Avould  afford  a  temporary  measure  of  relief  pending  the  extension  of  the 

system,  without  appreciable  loss  when  the  entire  project  was  completed. 

Respectfully  submitted, 

_  T  OA  (Sgd.)    Geo.  E.  Datesman. 

Philadelphia,  January  30,  1914.  v  &  ' 


CHAPTER  II 


REPORTS  ON  SPECIAL  TOPICS 

SECTION  I 

RELATION  BETWEEN  THE  DISPOSAL  OF  THE  SEWAGE  AND  THE  DEATH 
RATE  AND  A  REPORT  BY  WALTER  F.  WILLCOX  ON  THE  CRUDE 
AND  CORRECTED  DEATH  RATES  OF  NEW  YORK,  LONDON, 
BERLIN  AND  PARIS  FOR  THE  10  YEARS  1900-1909 

Since  the  system  of  main  drainage  proposed  by  the  Commission  will  eventually 
cost  many  millions  of  dollars,  it  is  desirable  that  the  taxpayers  should  understand  the 
benefits  to  accrue  from  it. 

The  most  important  benefit  would  be  to  health.  The  argument  upon  this  head, 
although  circumstantial  and  incapable  of  mathematical  demonstration,  is  neverthe- 
less conclusive.  It  rests  upon  the  known  relations  which  now  exist  between  the  pol- 
luted condition  of  the  harbor  and  the  public  health,  as,  for  example,  bathing,  shell- 
fish, driftwood,  flies  and  odors  and  the  possibility  of  materially  reducing  the  death 
rate  through  a  systematic  treatment  of  the  sewage.  The  relation  between  the  public 
health  and  pollution  was  discussed  in  the  Commission's  reports  of  April,  1910,  Part 
III,  Chap.  X,  and  August,  1912,  Part  II,  Chap.  I,  II  and  III.  The  opinion  was  reached 
that  whereas  no  definite  effect  upon  the  death  rate  could  be  ascribed  to  the  polluted 
state  of  the  harbor,  it  was  impossible  to  avoid  the  conclusion  that  a  considerable 
amount  of  harm  was  produced.  The  present  unsatisfactory  conditions  of  sewage  dis- 
posal and  the  possibility  of  reducing  the  death  rate  are  briefly  discussed  in  this  place. 

On  comparing  the  death  rates  of  New  York  with  those  of  London,  Paris  and  Ber- 
lin for  the  last  year  for  which  the  statistics  of  all  four  of  these  cities  are  available,  it 
appears  that  New  York's  rate  was  exceeded  only  by  that  of  Paris.  For  the  10  years 
ending  in  1909,  New  York  stood  at  the  bottom  of  the  list.  London  and  Berlin  were 
well  in  the  lead.  These  facts  referred  both  to  the  crude  and  corrected  death  rates,  as 
shown  in  the  following  table : 


TABLE  XXV 
Death  Rates,  1900-1909 


Crude 

Corrected  by  U.  S.  Registration  Data 

Average 
1900-1909 

1900 

1909 

Decrease 

Average 
1900-1909 

1900 

1909 

Decrease 

15.7 

18.6 

14.0 

4.6 

15.4 

18.2 

13.7 

4.5 

16.6 

19.0 

15.1 

3.9 

18.0 

20.6 

16.4 

4.2 

New  York  

18.5 

20.6 

16.0 

4.6 

20.1 

22.5 

17.5 

5.0 

18.0 

19.6 

17.2 

2.4 

18.8 

20.5 

18.0 

2.5 

274 


REPORTS  OF  EXPERTS 


For  the  purpose  of  studying  the  relative  healthfulness  of  cities,  corrected  death 
rates  are  indispensable,  since  they  have  for  their  object  the  elimination  of  differences 
in  the  population  which  considerably  affect  the  results.  When  the  corrected  death 
rates  of  the  four  cities  here  mentioned  are  compared,  it  is  seen  that  the  death  rate  of 
New  York  is  higher  than  the  crude  rate  indicates,  whereas  the  corrected  rate  for  Lon- 
don is  lower  than  the  crude  rate  for  that  city.  Consequently,  the  difference  in  health- 
fulness  between  London  and  New  York  is  seen  to  be  greater  than  the  crude  death  rates 
indicate.  London's  crude  rate  of  14  is  12y2  per  cent,  less  than  New  York's  crude  rate 
of  16,  and  London's  corrected  rate  of  13.7  is  over  21  per  cent,  less  than  New  York's 
corrected  rate  of  17.5. 

Comparing  New  York  with  the  other  cities  in  the  group,  it  will  be  seen  that 
Berlin's  corrected  rate  of  16.4  is  6.3  per  cent,  lower  than  the  corrected  rate  for  New 
York.    New  York's  corrected  rate  is  exceeded  by  that  of  Paris  by  2.8  per  cent. 

There  appears  to  be  no  reason  why  New  York  should  not  have  as  low  a  death 
rate  as  London  or  Berlin.  On  the  contrary,  it  can  apparently  have  the  lowest  rate  of 
any  city  of  its  class,  and  the  attainment  of  this  result  should  be  the  aim. 

New  York  is  a  good  example  of  a  city  of  the  largest  class  wherein  the  highest 
requirements  of  sanitation  are  demanded  and  are,  at  the  same  time,  capable  of  being 
satisfied.  Occupying  an  unrivaled  situation,  a  favorable  climate,  good  and  abundant 
water  supply  and  an  efficient  health  administration,  it  should  be  the  aim  of  every 
citizen  to  make  New  York's  death  rate  the  lowest  to  be  found  among  the  municipal- 
ities of  the  class  to  which  this  city  belongs.  New  York  should  be  the  cleanest  city  in 
the  world  if  for  no  other  reason  than  to  afford  a  barrier  against  the  danger  which 
results  from  the  immense  influx  of  immigrants  from  all  parts  of  the  world  who,  not 
infrequently,  bring  epidemic  diseases  to  this  port,  a  danger  which  is  intensified  by 
the  highly  congested  conditions  under  which  most  of  the  population  lives  and  works. 

Owing  to  the  congestion  of  population,  practically  all  the  conditions  necessary  to 
maintain  life  in  a  wholesome  way  must  be  secured  through  a  careful  and  skillful 
observance  of  sanitary  rules  and  principles.  This  relates  not  only  to  the  food,  cloth- 
ing and  habitations  of  the  people,  but,  in  a  peculiar  degree,  to  the  care  of  their  wastes. 
Upon  the  prompt  and  complete  disposal  of  these  wastes  largely  depends  the  comfort, 
convenience  and  healthfulness  of  the  city. 

The  Unsatisfactory  Conditions  of  Sewage  Disposal 

The  history  of  sanitation  shows  that  the  greatest  strides  of  progress  have  often 
resulted  from  great  object  lessons,  such  as  epidemics,  plagues  and  pestilences  which 
have  pointed  strikingly  to  the  fact  that  the  problem  of  disposing  of  the  human  wastes 
was  not  being  properly  dealt  with.    Such  sanitary  emergencies  now  rarely  occur  in 


REPORT  OF  WALTER  F.  WILLCOX  275 

the  largest  centers  of  population  and  are  no  longer  to  be  expected  in  the  city  of  New 
York,  which  possesses  an  efficient  health  administration.  Sanitation  in  cities  of  this 
class  now,  and  in  future,  may  be  expected  to  progress  upon  modern  scientific  and 
conservative  lines.  The  conditions  to  be  controlled  must  be  discovered  and  provided 
for  before  they  result  in  nuisance  and  disease.  Large  schemes  for  sanitary  improve- 
ment must  be  made  and  made  after  careful  investigation  while  yet  there  is  time.  This 
is  the  way  in  which  the  new  water  supply  of  New  York  was  provided  for.  No  great 
epidemic  or  conflagration  or  drought  pointed  to  its  necessity.  Competent  and  far- 
sighted  investigations  pointed  to  its  necessity,  it  was  recognized  that  some  years 
would  be  required  for  its  construction  and  the  city  proceeded  to  spend  $160,000,000 
to  carry  it  out. 

The  most  important  sanitary  provisions  which  a  modern  city  can  possess  are  the 
public  water  supply  and  sewerage  system.  The  relation  between  these  two  public 
services  is  very  close.  Aside  from  a  small  proportion  of  the  water  which  is  used  for 
drinking  purposes  and  for  the  extinguishment  of  fires,  nearly  the  whole  of  the  public 
water  supply  is  used  for  cleansing,  that  is,  for  the  removal  of  bodily,  household  and 
street  wastes. 

The  sanitary  function  of  water  is  to  act  as  a  vehicle  in  removing  the  waste  mate- 
rials from  their  source.  To  be  satisfactory,  this  removal  should  be  prompt,  complete 
and  unattended  by  injury  to  health  or  offense  to  the  senses.  Removal  to  a  certain 
distance  from  its  points  of  origin  usually  can  be  accomplished  satisfactorily  up  to  a 
certain  point  by  modern  sewerage  systems,  but  the  disposal  of  the  sewage  at  the  out- 
lets of  these  systems  often  presents  a  problem  of  great  difficulty. 

Until  recently  there  has  been  no  question  as  to  the  efficiency  of  the  custom  of 
sewage  disposal  pursued  by  New  York  and  its  neighboring  municipalities.  House 
sewage  and  street  washings  have  been  discharged  without  regulation  or  purification 
of  any  kind  into  the  nearest  tide  waters.  Investigation  has  shown  that  it  is  unwise 
longer  to  count  blindly  upon  the  purifying  action  of  dangerous  and  offensive  wastes 
which  are  discharged  every  day  into  the  arms  of  the  harbor  which  intersect  the  cit> 
in  every  direction.  Only  a  part  of  the  sewage  is  flushed  out  to  sea;  some  is  turned 
into  gas ;  some  is  liquefied  by  the  bacteria  in  the  water,  and  some  is  stored  in  pockets 
and  sludge  banks.  All  of  these  processes  are  attended  with  more  or  less  nuisance. 
Gradually  the  harbor  as  a  whole  is  becoming  over-polluted. 

Possibility  of  Reducing  the  Death  Rate 

That  a  material  reduction  can  be  made  in  the  death  rate  seems  assured  by  the 
reduction  which  has  been  made  in  it  during  recent  years,  from  the  fact  that  this  city 


276  REPORTS  OP  EXPERTS 

does  not  now  possess  a  large  death  rate  as  compared  with  London  or  Berlin,  and 
from  the  fact  that  such  a  reduction  always  follows  the  introduction  of  a  great  sani- 
tary improvement. 

New  York  stands  third  among  the  four  great  cities  in  regard  to  its  death  rate,  the 
crude  or  uncorrected  rates  for  which  are  commonly  but  erroneously  assumed  to  give 
a  correct  basis  for  comparing  the  relative  health  of  the  populations.  The  crude  death 
rate,  which  is  obtained  by  multiplying  the  number  of  deaths  per  year  by  one  thousand 
and  dividing  by  the  population  gives  an  imperfect  knowledge  of  the  healthfulness  of 
a  city,  since  it  fails  to  take  account  of  well-recognized  differences  in  susceptibility  to 
disease  which  exist  among  different  elements  in  the  population.  Females  have  lower 
death  rates  than  males,  in  consequence  of  which  a  city  which  has  an  unusually  large 
proportion  of  males  is  healthier  than  it  appears  to  be.  Young  children  and  old  per- 
sons have  a  higher  death  rate  than  the  average,  from  which  it  follows  that  a  city  in 
which  there  is  an  unusually  large  proportion  of  persons  in  middle  age  is  less  healthy 
than  it  seems. 

Among  the  most  important  causes  of  these  differences  in  susceptibility  in  the 
greatest  cities  are  those  which  are  due  to  sex  and  age.  A  proper  comparison  of  the 
healthfulness  of  cities  cannot  be  made  until  their  crude  death  rates  have  been 
corrected. 

In  1913  the  Commission  requested  Prof.  Walter  F.  Willcox,  the  eminent  statis- 
tical expert  of  Cornell  University,  to  report  on  the  corrected  death  rate  of  New  York 
City,  comparing  the  age  and  sex  distribution  of  New  York,  London,  Paris  and  Berlin 
with  each  other  through  some  standard  population.  Professor  Willcox  found  that  in 
London,  Paris,  Berlin  and  New  York  the  females  outnumber  the  males.  The  differ- 
ence is  least  in  New  York,  4  in  10,000  and  greatest  in  Paris  G38  in  10,000.  The  effect 
of  the  correction  to  be  made  on  this  account  is  to  raise  the  rate  for  New  York. 

New  York  has  a  larger  proportion  of  persons  in  the  healthy  ages  than  any  of  the 
other  cities  with  which  it  can  be  compared.  Among  every  10,000  persons  in  New  York, 
there  are  249  more  than  there  are  in  London  who  belong  to  the  healthy  ages.  The 
effect  of  the  correction  to  be  made  on  this  account  is  to  lower  the  rate  for  New 
York. 

The  corrections  for  sex  and  age  to  some  extent  counterbalance  each  other.  If  cor- 
rected for  sex,  New  York  would  have  a  lower  death  rate  than  any  of  the  other  three 
cities;  if  for  age,  the  rate  would  be  higher.  The  combined  effect  is  to  make  the  crude 
death  rate  lower  than  it  should  be.  This  influence  is  stronger  in  New  York  than  in 
any  of  the  other  cities. 


REPORT  OF  WALTER  F.  WILLCOX 


277 


REPORT  OF  WALTER  F.  WILLCOX 

President  George  A.  Soper, 

Metropolitan  Sewerage  Commission  of  New  York. 

Sir  :  You  have  asked  me  to  report  on  the  corrected  death  rate  of  New  York  City, 
comparing  the  sex  and  age  distribution  of  the  population  in  New  York,  London,  Paris 
and  Berlin  through  some  standard  population  and  showing  what  influence  the  differ- 
ences between  the  standard  population  and  the  population  of  these  cities  would  have 
on  the  death  rate  of  New  York  City  for  the  decade,  1900-1910. 

The  first  difference  to  be  examined  is  that  in  the  proportion  of  the  sexes.  It  is  well 
known  that  the  female  sex  has  a  lower  average  death  rate  than  the  male.  If  the  pop- 
ulations of  these  cities  differ  much  from  the  standard  and  from  each  other  in  the  pro- 
portion of  the  sexes,  that  fact  would  exert  some  influence  upon  their  death  rates.  To 
show  whether  the  populations  of  these  cities  do  thus  differ,  Table  XXX  (see  Appendix) 
has  been  prepared,  showing  the  per  cent,  of  each  sex  in  the  total  population  at  the  last 
available  census. 

From  the  last  column  of  Table  XXX  it  appears  that  in  each  of  the  four  cities  the 
females  outnumber  the  males.  In  New  York  City  the  difference  is  insignificant — only 
four  in  ten  thousand ;  in  the  other  three  cities  the  difference  is  much  greater — in  Berlin 
346,  in  London  596  and  in  Paris  638  in  ten  thousand.  The  effect  of  this  difference 
between  New  York  and  the  three  great  European  capitals  would  be  to  raise  the  crude 
or  uncorrected  death  rate  of  New  York  City.  To  test  the  fact  and  measure  the 
amount  of  this  influence,  I  have  taken  the  average  death  rates  by  sex  in  England  and 
Wales  during  the  decade  1891-1900  and  those  in  the  registration  area  of  the  United 
States  in  1900  as  standards  and  applied  them  to  the  male  and  female  population  of 
each  of  the  four  cities.   The  results  appear  in  Table  XXXI. 

In  such  a  computation,  which  shows  merely  the  effect  of  diversities  in  sex  propor- 
tions, the  city  with  the  largest  proportion  of  females,  Paris,  naturally  has  the  lowest 
death  rate  and  the  city  with  the  smallest  proportion  of  females,  New  York,  the  high- 
est death  rate.  But  the  difference  between  these  extremes,  a  difference  which  meas- 
ures the  effect  of  divergencies  in  sex  proportion  upon  the  death  rate,  is  only  two-fifths 
of  one  per  cent,  of  the  death  rate  in  Paris. 

The  death  rate  is  modified  by  divergencies  in  age  distribution  far  more  than  it  is 
by  divergencies  in  sex  distribution.  This  is  due  to  two  cooperating  causes:  (1)  cities 
differ  from  one  another  in  the  proportions  of  their  population  at  various  ages  far 
more  than  they  differ  in  the  proportions  of  the  two  sexes;  (2)  age  periods  differ  from 
one  another  in  death  rates  far  more  than  the  sexes  differ. 

To  ascertain  the  differences  in  the  age  proportions  of  the  population  of  the  four 
cities,  Table  XXXII  has  been  prepared.  The  italicized  and  bracketed  figures  for  Paris 
are  those  in  which  only  the  total  for  the  period  is  known.  This  total  has  been  distributed 
to  its  divisions  by  assuming  that  the  proportion  in  Paris  agreed  with  the  average  pro- 
portions in  the  other  three  cities.  The  same  method  of  estimating  has  been  used  in 
a  few  other  cases  in  later  tables. 

Both  table  and  diagram  show  very  wide  differences  between  the  cities.  In  New 
York  children  under  five  years  of  age  make  more  than  one  tenth  of  the  population ;  in 
Paris  they  make  only  one  sixteenth.    On  the  other  hand,  in  New  York  people  45  to 


278 


REPORTS  OF  EXPERTS 


49  years  of  age  make  one  nineteenth  of  the  population,  while  in  Paris  they  make 
one  fourteenth.  Similar  differences  appear  up  and  down  the  scale  of  age  periods. 
These  periods  may  be  grouped  into  two  main  classes,  the  healthy  ages  and  the 
unhealthy  ages,  the  former  including  the  periods  during  which  the  death  rate  is 
below  the  average  rate  at  all  ages,  the  latter  including  the  periods  during  which  the 
death  rate  is  above  that  average  rate.  The  healthy  ages  are  approximately  those  from 
5  to  54  years ;  the  unhealthy  ages  are  those  below  the  age  of  5  or  above  the  age  of  54. 
The  proportion  of  persons  at  healthy  ages,  as  thus  denned,  varied  from  81.96  per  cent, 
for  New  York,  down  to  78.47  per  cent,  for  London.  Among  every  ten  thousand 
residents  of  New  York  there  are  249  more  than  there  are  in  London  who  belong  to 
the  healthy  ages.  These  two  differences  between  New  York  and  the  other  three  cities 
influence  the  death  rate  in  opposite  ways,  the  large  proportion  of  males  tending  to 
raise  the  rate  and  the  large  proportion  of  persons  at  healthy  ages  tending  to  lower  it. 

The  next  step  is  to  measure  the  net  effect  of  these  differences  in  age  distribution, 
as  the  net  effect  of  differences  in  sex  distribution  has  already  been  measured.  In 
doing  so  I  have  used,  as  before,  two  sets  of  standard  death  rates ;  the  first  those  shown 
by  the  population  of  England  and  Wales  during  the  last  decade  available,  1891-1900, 
and  the  second  those  shown  by  the  population  of  the  registration  area  of  the  United 
States  in  1900.  These  two  sets  of  death  rates  are  shown  in  Table  XXXIII ;  those  for 
the  registration  area  of  the  United  States  in  1900  computed  from  MSS.  furnished  by  the 
Census  Bureau;  those  for  England  and  Wales  taken  from  the  Decennial  Supplement 
for  1891-1900. 

The  number  of  deaths  computed  by  comparison  with  each  standard  and  the 
resulting  computed  death  rates  corrected  for  age  distribution  are  shown  in  Tables 
XXXIV  and  XXXV.  They  show  that,  if  correction  is  made  for  age  distribution  alone, 
New  York  City  would  have  a  lower  death  rate  than  any  of  the  other  three  cities; 
Table  XXXI  has  shown  that,  if  correction  is  made  for  sex  distribution  alone,  New 
York  City  would  have  a  higher  death  rate  than  any  of  the  other  three  cities.  The  gen- 
eral result  of  these  two  comparisons  is  clearly  apparent  from  the  following  summary,  in 
which  the  death  rate  of  New  York  City  has  been  taken  as  the  base,  or  1,000,  and  the 
rates  in  other  cities  compared  with  it. 

TABLE  XXVI 

Death  Rates  op  London,  Paris  and  Berlin  Corrected  Separately  for  Sex  and  for 
Age  and  Compared  with  the  Corresponding  Death  Rates  for  New  York  as  a 
Base=1,000 


City 

Corrected  for  Sex  Only  by 
Comparison  with 

Corrected  for  Age  Only  by 
Comparison  with 

U.  S.  Regis- 
tration Area 

England  and 
Wales 

U.  S.  Regis- 
tration Area 

England  and 
Wales 

New  York  

1,000 
998 
997 
997 

1,000 
998 
996 
997 

1,000 
1,017 
1,047 
1,116 

1,000 
1,020 
1,049 
1,134 

Berlin  

London  

The  foregoing  summary  shows  that,  whichever  standard  is  used,  the  cities  stand 
in  the  same  order  and  with  somewhat  similar  differences  between  them.  It  shows 
also  that  the  sex  distribution  of  population  in  New  York  would  tend  to  produce  a 


REPORT  OF  WALTER  F.  WILLCOX 


279 


high  death  rate  and  the  age  distribution  would  tend  to  produce  a  low  death  rate  in 
comparison  with  the  other  cities.  It  suggests  that  in  the  case  of  New  York  the  in- 
fluence of  the  favorable  age  distribution  upon  the  death  rate  is  probably  greater  than 
the  influence  of  the  unfavorable  sex  distribution.  But  it  does  not  afford  any  way  of 
measuring  the  net  or  resultant  effect  of  those  two  opposing  influences.  Which  is  the 
stronger  and  how  much  stronger  is  it? 

To  answer  this  question  the  population  of  each  of  the  four  cities  has  been  distrib- 
uted both  by  sex  and  by  age.  The  results  of  this  distribution  are  expressed  in  Table 
XXXVI.  Then  the  number  in  each  sex  and  age  class  in  each  city,  e.  g.,  the  number  of 
female  children  under  5  years  of  age  in  Paris,  has  been  multiplied  by  the  death  rate 
of  that  lass  in  each  of  the  two  areas  given  in  Table  XXXVII,  the  products  appearing 
in  Tables  XXXVIII  and  XXXIX.  In  those  tables  the  products  showing  the  computed 
deaths  have  been  summed  and  the  total  divided  by  the  total  population.  The  quo- 
tients show  the  death  rates  which  would  have  been  found  in  each  city  if  its  death  rate 
at  each  sex  and  age  period  had  agreed  exactly  with  that  of  the  corresponding  sex  and 
age  period  in  the  standard  population.   This  quotient  is  called  the  standard  death  rate. 

The  differences  between  the  standard  death  rates  do  not  correspond  at  all  to  the 
actual  differences  in  the  healthfulness  of  these  four  cities,  for  by  hypothesis  all  such 
actual  differences  have  been  excluded,  and  the  death  rate  of  a  given  sex  and  age  class 
is  the  same  in  all  four  cities.  They  do,  however,  measure  at  least  approximately  the 
effect  of  the  only  differences  which  remain,  the  differences  in  sex  and  age  composition. 
The  general  result  of  such  a  computation  appears  in  the  following  summary: 

TABLE  XXVII 


Standard  Death  Rates  of  New  York,  London,  Paris  and  Berlin  Corrected  for  Both 
Sex  and  Age  by  Assuming  the  Death  Rates  in  the  Registration  Area  of  the 
United  States.  1900,  and  Those  in  England  and  Wales,  1891-1900,  as  Standards 


ClTT 

Standard  Death  Rate  Accepting 
the  Rates  in 

Ratio  of  Standard  Death  Rate 
to  that  of  New  York  =  1000 

U.  S.  Regis- 
tration Area 
1900 

England  and 
Wales 
1891-1900 

U.  S.  Regis- 
tration Area 
1900 

England  and 
Wales 
1891-1900 

New  York  

16.08 

15.91 

1,000 

1,000 

16.28 

16.12 

1,012 

1,012 

16.80 

16.58 

1,045 

1,042 

17.92 

17.96 

1.114 

1,129 

The  preceding  summary  shows  that  New  York  City  has  a  standard  death  rate 
lower  than  that  in  either  population  with  which  it  is  compared  or  that  in  any  one  of 
the  other  three  cities.  In  other  words,  the  combined  or  resultant  effect  of  its  sex  and 
age  composition  is  to  lower  rather  than  raise  its  death  rate.  This  influence  is  more 
marked  in  New  York  than  in  any  of  the  other  cities,  for  the  standard  death  rate  of 
Berlin  is  1-2  per  cent,  higher,  that  of  Paris  4-5  per  cent,  higher  and  that  of  London 
11-13  per  cent,  higher  than  that  of  New  York. 

After  this  complicated  process  has  yielded  the  standard  death  rate,  the  next  step 
is  to  find  the  factor  for  correction  in  each  city,  or,  in  other  words,  the  ratio  by  which 


280 


REPORTS  OP  EXPERTS 


the  crude  death  rate  of  the  city  must  be  multiplied  in  order  to  get  the  death  rate  cor- 
rected for  diversities  in  sex  and  age  distribution,  or,  briefly,  the  corrected  death  rate. 
The  results  are  shown  below. 


TABLE  XXVIII 


City 

Standard  Death  Rate  Based  on 

Factor  for  Correction  Based  on 

U.  S.  Regis- 
tration Area 

England  and 
Wales 

U.  S.  Regis- 
tration Area 

England  and 
Wales 

16.08 

15.91 

1.091 

1.144 

16.28 

16.12 

1.083 

1.128 

16.80 

16.58 

1.045 

1.097 

17.92 

17.96 

.979 

1.013 

The  factors  for  correction  indicate  the  ratio  by  which  the  crude  death  rate  of  the 
city  in  question  should  be  changed  before  it  is  fair  to  compare  it  with  the  crude  death 
rate  of  the  standard  population.  Each  standard  population  must  yield  its  own  series 
of  factors  for  correction  and  it  is  far  from  surprising  that  they  differ  widely. 

The  final  step  in  the  process  is  to  multiply  the  recorded  or  crude  rates  by  these 
factors  for  correction  and  thus  obtain  two  sets  of  corrected  death  rates,  one  derived 
from  each  standard  population.  The  crude  rates  are  given  in  Table  XL ;  the  corrected 
rates  in  Tables  XLI  and  XLII.  In  the  seven  years  1900-1906,  New  York  City  had  a 
higher  crude  death  rate  than  any  of  the  other  three  cities,  but  in  the  five  years  1907- 
1911,  the  crude  death  rate  of  Paris  was  higher  than  that  of  New  York.  Each  of  these 
three  tables  contains  32  death  rates  to  be  compared  with  the  death  rate  in  New 
York.  Of  the  32  crude  rates,  27  are  below  those  of  New  York  for  the  same  year;  of 
the  32  corrected  rates,  29  are  below  those  of  New  York  for  the  same  year.  But  the 
main  effect  of  correction  is  to  widen  the  differences  between  the  cities.  This  appears 
from  the  following  summary  in  which  1  and  2  refer  to  the  United  States  Registration 
area  and  England  and  Wales,  respectively : 

TABLE  XXIX 

Difference  Between  the  Death  Rate  of  New  York  and  That  of  Lowest  City 

in  Year  Specified 


Yeab 


1900  

1901  

1902  

1903  

1904  

1905  

1906  

1907  

1908  

1909  

Average 


Crude  Rate 


3.2 
3.7 
2.5 
2.0 


2.9 


Difference  in 


Corrected  Rate 


4.3 
5.0 
2.8 
4.7 
6.1 
5.3 
5.2 
5.7 
4.3 
3.8 


4.7 


4.8 
5.5 
3.0 
5.2 
6.7 
5.8 
5.6 
6.1 
4.6 
4.1 


5.1 


REPORT  OF  WALTER  F.  WILLCOX 


281 


So  long  as  the  death  rate  of  New  York  remains  nearly  or  quite  as  high  as  that  of 
any  of  the  other  cities,  and  the  sex  and  age  composition  of  the  several  populations 
remains  substantially  as  at  present,  the  effect  of  correction  will  be  to  increase  the 
differences  between  New  York  and  the  other  cities.  But  if  New  York's  death  rate 
should  become  nearly  or  quite  as  low  as  that  of  any  of  the  other  cities,  then  the  effect 
of  correction  would  be  to  decrease  the  differences  between  the  extremes. 

Yours  respectfully, 

Walter  F.  Willcox. 

November  10,  1913. 


APPENDIX 


TABLE  XXX 

Sex  Proportion  of  the  Total  Population  in  New  York  City,  London, 

Paris  and  Berlin 


City 

Date  of 
Census 

Total 
Population 

Males 

Females 

Per( 
Male 

2ent. 
Female 

Excess  of 
Females 

Paris1  

Berlin4  

1910 
1911 
1906 
1905 

4,766,883 
4,521,685 
2,719,924 
2,040,148 

2,382,482 
2,126,341 
1,273,144 
984,804 

2,384,401 
2,395,344 
1,446,780 
1,055,344 

49.98 
47.02 
46.81 
48.27 

50.02 
52.98 
53.19 
51.73 

0.04 
5.96 
6.38 
3.46 

1The  figures  for  New  York  in  this  and  later  tables  are  derived  from  proof  sheets  kindly  furnished  me  by  the 
Census  Bureau. 

JThe  figures  for  London  in  this  and  later  tables  are  derived  from  Census  of  England  and  Wales,  1911,  Vol  VII, 
kindly  sent  me  from  the  General  Register  Office.  They  apply  to  "Registration  London,"  excluding  the  "Outer 
Ring,"  and  include  thus  not  much  more  than  three-fifths  of  the  population  of  "Greater  London." 

'The  figures  for  Paris  in  this  and  later  tables  are  derived  from  the  Census  of  France,  1906,  Vol.  1,  Part  2,  pp. 
160-165. 

4The  figures  for  Berlin  in  this  and  later  tables  are  derived  from  Stat.  Jahrbuch  d.  Stadt  Berlin,  Vol.  31,  p.  1. 

TABLE  XXXI 


Computed  Death  Rates  of  New  York  City,  London,  Paris  and  Berlin  Corrected 

for  Differences  in  Sex  Proportion 


City 

Sex 

Population 
of  Known 
Age 

Death  Rate 
of  U.  S.  Reg- 
istration 
Area,  1900 

Com- 
puted 
Deaths 
by  Sex 

Sum  of 
Deaths 

Com- 
puted 
Death 
Rate 

Death  Rate 
of  England 
and  Wales, 
1891-1900 

Com- 
puted 
Deaths 
by  Sex 

Sum  of 
Deaths 

Com- 
puted 
Death 
Rate 

New  York . 

London  

Paris  

{Male... 
\  Female. 
1  Male. . . 
\  Female. 
{Male... 
\  Female. 
(  Male.. . 
\  Female. 

2,382,482 
2,384,401 
2,126,341 
2,395,344 
1,273,144 
1,446,780 
984,804 
1,055,344 

18.57 
16.53 
18.57 
16.53 
18.57 
16.53 
18.57 
16.53 

44,240 
39,410 
39,482 
39,598 
23,642 
23,918 
18,288 
17,444 

]  83,650 
1  79,080 
1  47,560 
1  35,732 

17.55 
17.49 
17.49 
17.51 

/  19.32 
1  17.14 
/  19.32 
\  17.14 
/  19.32 
\  17.14 
/  19.32 
I  17.14 

46,030 
40,870 
41,081 
41,056 
24,595 
24,800 
19,025 
18,090 

}  86,900 
]  82,137 
j  49,395 
I  37,115 

18.23 
18.17 
18.16 
18.19 

282 


REPORTS  OF  EXPERTS 


TABLE  XXXII 


Age  Proportion  of  the  Population  of  Known  Age  of  New  York,  London, 

Paris  and  Berlin 


Age  Period 

liCtV    lUln.  \_/lLY) 

1Q10 

.LjOLIUUU, 

1Q1 1 

1.9X1 

Paris, 
1906 

1 Q05 

All  a  (Too 

10  000 

10  000 

10,000 

10  000 

Under  5  

1,065 

1,034 

632 

876 

5—9  

920 

960 

600 

816 

10—14  

887 

889 

617 

773 

15—19  

961 

897 

791 

930 

20—24  

1,118 

948 

997 

1,154 

25—29  

1,049 

930 

1,151 

1,115 

30—34  

888 

830 

1,037 

905 

35—39  

803 

746 

917 

791 

40—44  

651 

641 

810 

665 

45—49  

517 

551 

701 

548 

50—54  

402 

455 

548 1 

442 

55—59  

256 

352 

396 

351 

60—64  

199 

279 

310 

258 

65—69  

131 

212 

228 

177 

70—74  

82 

144 

143' 

■  * 

105 

75—79  

42 

79 

78  j 

58 

80—84  

20 

36 

SO  1 

27 

85—89  

7 

13 

11 

■  * 

8 

90+  

2 

4 

s 

1 

*  Estimated  from  the  total  figures  50-59,  70-79  or  80  and  over,  by  applying  the  average  proportions  in  the  other 
three  cities. 


TABLE  XXXIII 


Death  Rates  by  Age  Periods  in  the  Registration  Area  of  the  United  States,  1900, 
and  in  England  and  Wales,  1891-1900,  Taken  as  Standard  Populations 


Age  Period 


Under  5 
5—  9 
10—14 
15—19 
20—24 
25—29 
30—34 
35—39 
40—44 
45—49 
50—54 


Death  Rates  of 


United  States 
Registration  Area, 
1900 


51.81 
5.08 
3.25 
5.18 
7.36 
8.37 
9.56 
10.52 
12.03 
14.69 
18.78 


England  and 
Wales, 
1891-1900 


57.74 
4.34 
2.51 
3.73 
4.74 

6.40 
10.51 
16.76 


Age  Period 


55—59 
60—64 
65—69 
70—74 
75—79 
80—84 
85—89 
90—94 
95+.. 


Death  Rates  of 


United  States 
Registration  Area 
1900 


25.43 
34.64 
50.75 
73.98 
109.24 
167.45 
241.39 
334.58 
401.75 


England  and 
Wales, 
1891-1900 


31.47 
65.04 

152.17 


REPORT  OF  WALTER  F.  WILLCOX 


283 


TABLE  XXXIV 


Computed  Death  Rate  of  New  York  City,  London,  Paris  and  Berlin  Corrected 
for  Differences  in  Age  Proportion  by  Using  the  Death  Rates  in  the  Registra- 
tion Area  of  the  United  States  in  1900  as  a  Standard 


Computed  Deaths  at  Specified  Age  Period  in 

Age  Period 

New  York 

London 

Paris 

Berlin 

Under  5 

9fi  979 

94  91 7 

8  875 

9,252 

5—9  

2,226 

2,203 

828 

845 

10 — 14  

1,373 

1,306 

545 

513 

15 — 19 

2,370 

2,101 

1,111 

982 

20—24  

3,915 

3,156 

1,990 

1,731 

25—29  

4,178 

3,521 

2,613 

1,902 

30—34  

4,039 

3,588 

2,687 

1,766 

35—39  

4,021 

3,547 

2,619 

1,697 

40-44  

3,728 

3,487 

2,640 

1,630 

45—19  

3,615 

3,658 

2,791 

1,644 

50—54  

3,589 

3,866 

2,789 

1,692 

55—59  

3,108 

4,046 

2,734 

1,818 

60—64  

3,270 

4,370 

2,917 

1,820 

65—69  

3,169 

4,830 

3,139 

1,814 

70—74  

2,906 

4,788 

2,880 

1,587 

75—79  

2,196 

3,902 

2,300 

1,302 

80—84  

1,540 

2,786 

1,401 

921 

85—89  

781 

1,298 

707 

401 

90—94  

286 

493 

227 

73 

95+  

80 

93 

49 

8 

Total  deaths  

76,662 

81,256 

45,842 

33,398 

Computed  death  rate  

16.10 

17.97 

16.86 

16.38 

TABLE  XXXV 

Computed  Death  Rate  of  New  York  City,  London,  Paris  and  Berlin  Corrected 
for  Differences  in  Age  Proportion  by  Using  the  Death  Rates  of  England 
and  Wales  in  1891-1900  as  a  Standard. 


Computed  Deaths  at  Specified  Age  Period  in 

Age  Period 

New  York 

London 

Paris 

Berlin 

Under  5  

29,279 

26,988 

9,891 

10,310 

5—9  

1,902 

1,882 

707 

722 

10—14  

1,060 

1,009 

421 

396 

15—19  

1,707 

1,513 

800 

707 

20—24  

2,521 

2,033 

1,282 

1,115 

25—34  

5,898 

5,094 

3,797 

2,636 

35—44  

7,274 

6,591 

4,923 

3,119 

45—54  

7,327 

7,624 

5,672 

3,386 

55—64  

6,816 

8,976 

6,033 

3,903 

65—74  

6,616 

10,461 

6,555 

3,744 

75+  

5,122 

9,147 

5,045 

2,939 

Total  deaths  

75,522 

81,318 

45,126 

32,977 

Computed  death  rate  

15.86 

17.98 

16.64 

16.17 

284 


REPORTS  OF  EXPERTS 


TABLE  XXXVI 

Sex  and  Age  Distribution  op  Population  op  New  York,  London,  Paris  and  Berlin 

to  Each  10,000  op  Known  Age 


Age  Period 


New  York,  1910 


Male 


Female 


London,  1911 


Male 


Female 


Paris,  1906 


Male 


Female 


Berlin,  1905 


Male 


Female 


All  ages 
Under  5 
5—  9. 
10—14. 
15—19. 
20—24. 
25—29. 
30—34. 
35—39. 
40-44. 
45—49. 
50—54. 
55—59. 
60—64. 
65—69.. 
70—74. , 
75—79.. 
80—84. . 
85—89. . 
90+. . . . 


4,995 
537 
460 
442 
454 
528 
533 
462 
413 
339 
268 
207 
128 
95 
62 
37 
18 
8 
3 
1 


5,005 
528 
460 
445 
507 
590 
516 
426 
390 
312 
249 
195 
128 
104 
69 
45 
24 
12 
4 
1 


4,702 
519 
478 
440 
427 
422 
419 
385 
349 
301 
259 
214 
164 
128 
93 
58 
29 
12 
4 
1 


5,298 
515 
482 
449 
470 
526 
511 
445 
397 
340 
292 
241 
188 
151 
119 
86 
50 
24 


4,6 


315 
296 
304 
380 
428 
551 
505 
436 
391 
334 

m\  + 

179  J 
132 
90 


26 
9 
3 
1 


5,314 
317 
304 
313 
411 
569 
600 
532 
481 
419 
367 
293  \ 
218  J 
178 
138 
91  1 


4,827 
440 
407 
380 
445 
594 
560 
451 
388 
322 
249 
198 
153 
107 
68 
37 
18 
8 
2 
0 


5,173 
436 
409 
393 
485 
560 
555 
454 
403 
343 
299 
244 
198 
151 
109 
68 
40 
19 
6 
1 


*  Estimated  from  the  total  figures  50-59,  70-79  or  80  and  over,  by  applying  the  average  proportions  in  the  other 
three  cities. 


TABLE  XXXVII 

Death  Rates  by  Age  and  Sex  in  the  Registration  Area  op  the  United  States,  1900, 
and  in  England  and  Wales,  1891-1900,  Taken  as  Standard  Populations 


Death  Rates  of 


Age  Period 

United  States  Registration  Area, 

England  and  Wales, 

1900 

1891- 

-1900 

Male 

Female 

Male 

Female 

56 

22 

47.34 

62.71 

52.80 

5—9  

5 

18 

4.97 

4.31 

4.37 

10—14  

3 

29 

3.21 

2.45 

2.57 

15—19  

5 

27 

5.10 

3.79 

3.67 

20—24  

7 

73 

7.01 

5.06 

4.46 

25—29  

30—34  

8 
9 

59 
54 

8.15 
8.71 

6.76 

6.08 

35—39  

40— a  

11 
12 

24 
99 

9.74 
10.98 

11.50 

9.69 

45—49  

50—54  

16 
20 

16 
50 

13.14 
18.01 

18.95 

14.74 

55—59  

60—64  

27 
37 

52 
49 

23.35 
31.92 

34.95 

28.44 

65—69  

70—74  

54 
78 

76 
06 

46.98 
70.14 

70.39 

60.72 

75—79  

115 

70 

103.40 

80—84  

175 

40 

160.90 

85—89  

252 

90 

232.80 

160.09 

146.46 

90—94  

350 

60 

325.20 

95+  

411 

80 

402.40 

KEPORT  OF  WALTER  P.  WILLCOX 


285 


TABLE  XXXVIII 


Computed  Death  Rate  of  New  York  City,  London,  Paris  and  Berlin  Corrected 
for  Differences  in  Sex  and  Age  Proportion  by  Using  the  Death  Rates  in  the 
Registration  Area  of  the  United  States  in  1900  as  a  Standard 


A  Pfrtod 

Computed  Deaths 

Male 

Female 

New  York 

London 

Paris 

Berlin 

New  York 

London 

Paris 

Berlin 

TTndpr  ,*5 

14,380 

13,187 

4,796 

5,042 

11,900 

11,023 

4,070 

4,207 

5—9  

1,134 

1,118 

416 

430 

1,090 

1,052 

411 

415 

10—14  

692 

655 

272 

255 

679 

652 

273 

257 

15—19  

1,139 

1,018 

543 

478 

1,232 

1,083 

570 

504 

20—24  

1,942 

1,477 

897 

935 

1,969 

1,669 

1,083 

801 

25—29  

2,178 

1,629 

1,283 

979 

2,002 

1,883 

1,327 

922 

30—34  

2,098 

1,660 

1,306 

878 

1,765 

1,753 

1,256 

807 

35—39  

2,209 

1,775 

1,331 

889 

1,809 

1,746 

1,272 

801 

40—44  

2,096 

1,767 

1,376 

852 

1,631 

1,690 

1,247 

768 

45—49  

2,061 

1,891 

1,462 

822 

1,558 

1,734 

1,307 

802 

50—54  

2,020 

1,988 

1,411 

827 

1,667 

1,961 

1,432 

896 

55—59  

1,681 

2,036 

1,338 

859 

1,427 

1,987 

1,378 

941 

60—64  

1,687 

2,162 

1,343 

817 

1,576 

2,186 

1,544 

982 

65—69  

1,619 

2,313 

1,341 

756 

1,544 

2,531 

1,756 

1,048 

70—74  

1,388 

2,031 

1,174 

587 

1,508 

2,715 

1,730 

977 

75—79  

986 

1,530 

817 

431 

1,198 

2,325 

1,454 

847 

80—84  

649 

989 

454 

275 

884 

1,770 

928 

633 

85—89  

316 

458 

211 

114 

463 

988 

489 

283 

90—94  

105 

130 

61 

20 

181 

358 

165 

52 

95+  

24 

25 

12 

2 

56 

69 

37 

6 

Total,  known  age. . . 

40,404 

39,839 

21,844 

16,248 

36,139 

41,175 

23,729 

16,949 

Both  sexes  

Standard  death  rate. 

76,543 
16.08 

81,014 
17.92 

45,573 
16.80 

33,197 
16.28 

TABLE  XXXIX 


Computed  Death  Rate  of  New  York  City,  London,  Paris  and  Berlin  Corrected 
for  Differences  in  Sex  and  Age  Proportion  by  Using  the  Death  Rates  in 
England  and  Wales,  1891-1900,  as  a  Standard 


Age  Period 

Computed  Deaths 

Male 

Female 

New  York 

London 

Paris 

Berlin 

New  York 

London 

Paris 

Berlin 

Under  5  

5—9  

10—14  

15—19  

20—24  

25—34  

35—14  

45—54  

55—64  

65—74  

75+  

Total,  known  age . . . 

16,037 
944 
516 
819 
1,271 
3,200 
4,116 
4,282 
3,707 
3,333 
2,214 

14,708 
931 
488 
733 
966 
2,458 
3,380 
4,055 
4,602 
4,804 
3,379 

5,351 
347 
202 
390 
587 
1,935 
2,580 
3,019 
2,954 
2,723 
1,711 

5,625 
358 
190 
344 
612 
1,393 
1,664 
1,728 
1,852 
1,501 
928 

13,272 

958 
544 
886 
1,252 
2,725 
3,205 
3,112 
3,144 
3,302 
2,894 

12,295 
951 
522 
779 
1,061 
2,629 
3,194 
3,551 
4,367 
5,624 
5,712 

4,540 
361 
218 
409 
689 
1,867 
2,341 
2,638 
3,054 
3,767 
3,299 

4,693 
365 
206 
363 
509 
1,251 
1,459 
1,633 
2,020 
2,200 
1,980 

40,439 

40,504 

21,799 

16,195 

35,294 

40,685 

23,183 

16,679 

Standard  death  rate. 

75,733 
15.91 

81,189 
17.96 

49,982 
16.58 

32,874 
16.12 

286  REPORTS  OF  EXPERTS 

TABLE  XL 


Crude  Death  Rates  op  New  York,  Berlin,  Paris  and  London,  1900-1909 


Date 

Crude  Death  Rates  of 

New  York1 

Berlin2 

Paris' 

London' 

1900  

20.6 

19.0 

19.6 

18.6 

1901  

19.9 

18.1 

18.7 

17.1 

1902  

18.6 

16.2 

18.3 

17.2 

1903  

18.0 

16.6 

17.4 

15.2 

1904  

20.1 

17.0 

17.7 

16.1 

1905  

18.4 

17.1 

17.6 

15.1 

1906  

18.3 

15.8 

17.6 

15.1 

1907  

18.3 

15.4 

18.4 

14.6 

1908  

16.3 

15.4 

17.4 

13.8 

1909  

16.0 

15.1 

17.2 

14.0 

1910  

16.0 

16.2 

1911  

15.2 

17.2 

'Figures  for  New  York  are  derived  from  Bureau  of  the  Census,  Mortality  Statistics,  1909,  p.  72,  Bulletin  109, 
p.  46  and  Bulletin  112,  p.  43. 

'Figures  for  Berlin  are  derived  from  Stat.  Jahrbuch  der  Stadt  Berlin,  XXXII,  p.  111. 

'Figures  for  Paris  are  derived  from  Annvaire  Slat,  de  la  Ville  de  Paris,  XXXI,  p.  200. 

'Figures  for  London  are  derived  from  Report  of  Medical  Officer  of  Health  of  London  County,  1908,  p.  8. 


TABLE  XLI 


Corrected  Death  Rates  op  New  York,  Berlin,  Paris  and  London,  Using  the  United 
States  Registration  Area,  1900,  as  a  Standard 


Date 

Corrected  Death  Rates  of 

New  York 

Berlin 

Paris 

London 

1900  

22.5 

20.6 

20.5 

18.2 

1901  

21.7 

19.6 

19.5 

16.7 

1902  

20.3 

17.5 

19.1 

16.8 

1903  

19.6 

18.0 

18.2 

14.9 

1904  

21.9 

18.4 

18.5 

15.8 

1905  

20.1 

18.5 

18.4 

14.8 

1906  

20.0 

17.1 

18.4 

14.8 

1907  

20.0 

16.7 

19.2 

14.3 

1908  

17.8 

16.7 

18.2 

13.5 

1909  

17.5 

16.4 

18.0 

13.7 

1910  

17.5 

16.9 

1911  

16.6 

18.0 

TABLE  XLII 

Corrected  Death  Rates  of  New  York,  Berlin,  Paris  and  London,  Using  England 

and  Wales,  1891-1900,  as  a  Standard 


Date 

Corrected  Death  Rates  of 

New  York 

Berlin 

Paris 

London 

1900  

23.6 

21.4 

21.5 

18.8 

1901  

22.8 

20.4 

20.5 

17.3 

1902  

21.3 

18.3 

20.1 

17.4 

1903  

20.6 

18.7 

19.1 

15.4 

1904  

23.0 

19.2 

19.4 

16.3 

1905  

21.1 

19.3 

19.3 

15.3 

1906  

20.9 

17.8 

19.3 

15.3 

1907  

20.9 

17.4 

20.2 

14.8 

1908  

18.6 

17.4 

19.1 

14.0 

1909  

18.3 

17.0 

18.9 

14.2 

1910  

18.3 

17.8 

1911  

17.4 

18.9 

REPORT  OF  SAMUEL  RIDEAL 


287 


SECTION  II 

CHEMICAL  OXIDATION  AS  A  PROCESS  OF  SEWAGE  TREATMENT  AND  A 
REPORT  BY  SAMUEL  RIDEAL  ON  OXIDATION  PROCESSES  AP- 
PLICABLE TO  NEW  YORK  CONDITIONS 

The  object  of  oxidizing  New  York's  sewage,  partly  or  completely,  by  chemicals 
would  be  to  remove  the  excessive  demand  which  the  sewage  makes  on  the  dissolved 
oxygen  in  the  harbor  water  and  so  permit  the  sewage  to  be  discharged  into  the  inner 
harbor  with  little  or  no  other  treatment. 

Aeration  and  Chemical  Oxidation  Compared 

Forced  aeration  has  been  suggested  for  this  purpose  by  various  investigators,  as 
it  has  previously  been  proposed  for  other  situations  and  as  it  has  subsequently  been 
recommended  in  connection  with  various  biological  processes,  but  aeration  is  not  a 
process  in  itself.  Its  function  is  not  to  oxidize  sewage,  but  to  supply  the  oxygen 
with  which  the  ordinary  purifying  forces  of  nature  can  carry  the  oxidizing  processes 
forward.  Its  benefits  are  slow  for  they  depend  not  only  upon  the  rate  at  which  sew- 
age will  absorb  oxygen,  but  upon  the  rate  at  which  the  natural  purifying  agencies 
will  appropriate  it. 

Aeration  is  especially  useful  where  the  oxygen  supply  is  deficient,  for  then  the 
rate  at  which  the  water  will  absorb  it  is  relatively  high.  Water  and  sewage  absorb 
oxygen  at  the  same  rate  and  to  the  same  extent  and,  as  has  been  shown  elsewhere, 
when  there  is  a  considerable  amount  of  dissolved  oxygen  present,  it  is  difficult  to  add 
more  by  aeration  or  by  any  other  means.  Where  large  quantities  of  oxygen  have  to 
be  supplied  by  aeration,  it  is  necessary  to  continue  the  process  over  a  long  period  of 
time  or  to  repeat  it  at  frequent  intervals.  Either  of  these  alternatives  is  likely  to 
prove  expensive  for  the  reason  that  they  make  it  necessary  to  provide  means  for  keep- 
ing the  sewage  on  hand  for  a  considerable  period. 

Chemical  oxidation  seeks  to  eliminate  the  slowness  and  inconvenience  of  the 
aeration  process  and,  by  aiming  directly  at  the  desired  reaeration,  to  affect  a  material 
gain.  Unlike  aeration,  chemical  oxidation  is  a  radical  form  of  treatment  which  in- 
volves abrupt  interruption  in  the  natural  course  of  self  purification  which  sewage 
ordinarily  undergoes  from  the  moment  it  is  produced  until  its  harmful  properties  are 
rendered  inert,  and  in  which  living  organisms  play  an  important  part.  Chemical 
oxidation,  by  whatever  method  it  is  carried  on,  means  a  sudden  arresting  of  the  nat- 
ural purifying  agencies,  a  rapid  and  intense  chemical  reaeration  between  the  oxidiz- 
ing agent  and  the  oxidizable  ingredients  of  the  sewage  and  the  final  discharge  of  the 


288  REPORTS  OF  EXPERTS 

effluent  in  a  state  which  is  not  inimical  to  the  fauna  and  flora  of  the  natural  body  of 
water  into  which  it  is  emptied.  Incidentally,  the  oxidation  produces  disinfection  and 
the  disinfecting  properties  of  the  oxidizing  matter  in  some  cases  prove  to  be  advan- 
tageous. Under  other  and  more  usual  circumstances,  it  may  prove  embarrassing,  as, 
for  example,  where  a  large  amount  of  sewage  effluent  possessing  antiseptic  properties 
is  discharged  into  water  which  is  inhabited  by  fishes. 

The  use  of  chemicals  to  purify  sewage  is  by  no  means  a  new  idea,  although  there 
are  apparently  no  existing  large  sewage  works  where  chemical  oxidation  is  practiced 
to  serve  as  an  example  of  the  size  and  arrangement  of  apparatus  needed  and  the  cost, 
efficiency  and  reliability  of  the  process.  Nevertheless,  considerable  help  in  forming  an 
opinion  on  the  leading  difficulties  to  be  overcome  can  be  obtained  from  the  experience 
gained  with  certain  standard  processes  of  water  and  sewage  treatment,  notably  the 
application  of  basic  sulphate  of  alumina,  lime  and  iron,  copper  sulphate  and  hypo- 
chlorite. 

Intended  Scope  of  De.  Rideai/s  Report 

Experiments  on  the  purification  of  New  Yorkls  sewage  through  the  electrolytic 
decomposition  of  sea  water  by  the  application  of  bleach  and  by  chlorine  led  the  Com- 
mission, in  1912,  to  seek  the  opinion  of  an  eminent  expert  on  chemical  questions  re- 
lating to  the  purification  of  sewage  and  disinfection,  and  Dr.  Samuel  Rideal  of 
London  was  requested  to  make  a  report  on  the  possibilities  of  direct  chemical 
oxidation. 

Dr.  Rideal,  a  Doctor  of  Science,  Fellow  of  the  University  College,  Fellow  of 
the  Institute  of  Chemistry  and  of  the  Sanitary  Institute  of  Great  Britain  and  Vice- 
President  of  the  Society  of  Chemical  Analysts  of  Great  Britain,  is  the  author  of  "Sew- 
age and  the  Bacterial  Purification  of  Sewage,"  "Water  and  its  Purification,"  and 
"Disinfection  and  Disinfectants,"  all  of  which  have  passed  through  several  editions. 

In  preparation  for  his  report,  Dr.  Rideal  made  a  personal  inspection  of  the  con- 
ditions of  sewage  disposal  in  New  York  harbor  and  visited  the  Commission's  office  to 
become  familiar  through  conferences  and  study  with  the  results  of  the  Commission's 
work.  His  report  is  a  discussion  of  the  questions  assigned  to  him  from  a  chemical  and 
theoretical  standpoint  and  makes  no  claim  either  to  finality  or  practicability,  which  he 
rightly  says  would  not  be  warranted  in  "so  short  a  report  nor  without  a  prolonged 
study  of  the  main  details  chiefly  of  an  engineering  character." 

In  a  letter  dated  October  3,  1912,  the  Commission  requested  Dr.  Rideal  to  report 
on  "other  ways  of  oxidizing  sewage  than  by  biological  means,  that  is,  through  the  use 
of  chemicals.    Absence  of  odor,  restricted  areas  of  land  and  freedom  in  the  effluent 


REPORT  OF  SAMUEL  RIDEAL  289 

from  substances  poisonous  to  fishes  should  be  features  of  such  procedures.  It  should 
be  remembered  also  that  the  process  must  be  applicable  to  large  volumes  of  sewage — 
not  less  than  25,000,000  or  30,000,000  gallons  per  24  hours,  for  example.  The  cost  of 
the  treatment,  including  the  purchase  of  materials  should  not  be  excessive,  nor  should 
the  process  involve  expense  for  pumping.  Inasmuch  as  processes  for  the  chemical 
oxidation  of  sewage  are  not  in  general  use,  it  will  be  desirable  to  give  such  assurance 
as  is  possible  that  any  process  suggested  can  actually  be  carried  out." 

In  addition  to  his  opinion  on  chemical  oxidation,  Dr.  Rideal  was  asked  if,  in  his 
view,  the  Commission  was  right  in  placing  importance  on  the  presence  of  sludge  on 
the  harbor  bottom  as  an  element  making  for  the  exhaustion  of  oxygen  from  the  water, 
whether  he  considered  it  possible  to  purify  the  sewage  sufficiently  near  its  points  of 
origin  to  permit  the  effluent  to  be  discharged  into  the  inner  harbor  and  to  give  his  im- 
pression of  the  condition  of  the  harbor  as  he  saw  it  on  his  trip  from  the  Battery  to  Hell 
Gate  on  October  2,  1912. 

Synopsis  of  the  Report 

It  is  Dr.  Rideal's  opinion  that  all  the  sewage  produced  now  and  in  the  next  gen- 
eration in  the  metropolitan  district  of  New  York  and  New  Jersey  can  be  sufficiently 
purified  on  properly  selected  sites  near  where  it  is  produced  to  permit  of  its  discharge 
locally  into  the  waters  of  the  inner  harbor  without  violating  any  of  the  provisions  of 
the  Commission's  standard  of  cleanness.  The  purification  works,  he  thinks,  should  be 
able  to  remove  the  unsightly  and  offensive  floating  suspended  matters  of  the  sewage 
and  insure  that  the  effluent  becomes  invisible  and  inodorous  when  mixed  with  the 
harbor  waters.  So  far  as  oxidation  is  concerned,  Dr.  Rideal  thinks  that  sufficient 
oxidizing  treatment  should,  and  can,  be  given  to  the  sewage  to  keep  the  effluent  from 
absorbing  more  than  one-half  of  the  oxygen  in  the  harbor  water. 

The  reagents  which  are  considered  available  for  the  oxidation  of  the  sewage  are 
few  in  number.  They  include  manganates  and  permanganates  and  oxidized  com- 
pounds of  chlorine.  The  first  two  would  be  prohibitively  costly.  Even  the  cost  of 
hypochlorite,  the  cheapest  oxidizing  agent,  would  be  too  expensive  for  use  with  crude 
sewage,  according  to  Dr.  Rideal's  report.  It  would  be  necessary  to  use  it  as  a  fin- 
isher to  the  mechanical  or  bacterial  process  which  would  remove  much  of  the  floating 
suspended  matters.  Sedimentation  basins  having  from  4  to  20  hours'  flow  are  sug- 
gested to  accomplish  the  removal  of  the  solids,  the  basins  to  operate  on  the  principle 
of  septic  tanks  or  sludge-digesting  tanks. 

In  addition  to  their  main  function  of  retaining  and  digesting  the  solids  so  as  to 
reduce  the  cost  of  the  chemicals,  the  basins  would  prevent  sludge  from  forming  on  the 


290  REPORTS  OF  EXPERTS 

harbor  bottom.  In  Dr.  Rideal's  opinion,  the  advantage  to  be  gained  in  this  respect 
would  be  of  small  value,  for  he  does  not  think  that  the  sludge  deposits  in  New  York 
harbor  are  as  responsible  as  the  liquid  part  of  the  sewage  in  exhausting  the  dissolved 
oxygen  from  the  water. 

If  it  was  not  possible  to  secure  space  for  septic  or  sludge-digesting  tanks  on  land, 
Dr.  Rideal  thinks  the  tanks  could  be  erected  in  the  water  along  Manhattan  Island 
and  elsewhere  with  the  necessary  chemical  equipments  by  their  side.  He  suggests 
that  the  basins  be  covered  to  prevent  nuisance.  The  sludge  having  attained  its  main 
decomposition  without  oxygen  could,  in  Dr.  Rideal's  opinion,  be  discharged  into  the 
harbor  with  no  fear  of  absorbing  much  oxygen  afterward.  The  effluent  should  be 
treated  at  the  outlet  by  a  small  quantity  of  the  oxidizer.  By  the  use  of  such  tanks  as 
he  proposes,  Dr.  Rideal  thinks  that  hardly  any  pumping  would  be  required. 

The  report  contains  calculations  on  the  amount  of  chlorine  necessary  and,  in  these, 
due  account  is  taken  of  the  oxygen  required  by  the  sewage,  the  quantity  of  oxygen 
which  is  brought  by  tidal  action  into  the  harbor  from  the  ocean,  that  which  is  contrib- 
uted by  the  land  water  from  the  rivers  and  that  which  is  absorbed  from  the  atmos- 
phere. The  object  of  the  chemical  process  would  be  to  supply  only  enough  oxidation 
to  supplement  the  natural  process  which  proceeds  in  the  harbor. 

To  completely  oxidize  the  1,500,000,000  gallons  per  day  of  sewage  included  in  the 
estimates,  Dr.  Rideal  finds  that  1,280  tons  of  available  chlorine  would  be  required  per 
day.  Basing  his  opinion  on  experiments  made  with  Philadelphia  sewage,  the  report 
indicates  that  New  York  harbor  sewage  could  be  disinfected  with  a  good  quality  of 
chloride  of  lime  in  the  proportion  of  27.9  tons  for  screened  sewage  and  19.5  tons  for 
screened  and  settled  sewage.  In  another  way  it  is  calculated  that  six  parts  per  million 
is  the  proper  dose  which  is  likely  to  prove  effectual. 

The  chlorine  could  be  added,  in  Dr.  Rideal's  opinion,  in  the  form  of  chlorine  gas, 
bleaching  powder  or  as  sodium  hypochlorite  produced  from  an  electrolyzed  solution 
of  sodium  chloride.  The  supply  of  sodium  chloride  could  be  obtained  from  the  harbor 
water  or  from  a  solution  of  rock  salt.  Sea  water  might  not  be  strong  enough  for 
practical  purposes,  its  weakness  possibly  requiring  works  of  too  large  size.  Electric 
bleach  works  usually  operate  with  5  to  15  per  cent,  sodium  chloride  solutions. 

A  considerable  part  of  Dr.  Rideal's  report  is  devoted  to  the  question  of  forced 
aeration  as  a  method  of  sewage  disposal  and  the  results  of  various  calculations  are 
given  to  show  that  it  would  be  impracticable  to  oxidize  New  York  sewage  by  this 
means.  At  the  conclusion,  the  report  recommends  that  chlorine  treatment  be  given 
serious  consideration  along  the  two  following  lines:  1,  Preliminary  screening  and 
sedimentation  to  produce  a  non-fermenting  sludge  which  can  be  discharged  into  the 


REPORT  OF  SAMUEL  RIDEAL  291 

harbor  waters  separately  without  robbing  them  of  any  dissolved  oxygen,  and,  2,  a 
chlorine  treatment  of  the  clarified  effluent  to  such  an  extent  as  will  insure  the  pro- 
posed minimum  standard  of  3  c.c.  of  dissolved  oxygen  per  litre  being  maintained 
throughout  the  whole  of  the  harbor  waters. 

The  Commission's  Opinion 

The  Commission  has  given  careful  consideration  to  Dr.  Rideal's  recommendation 
and  as  a  result  does  not  regard  his  proposition  as  affording  a  practical  solution  of 
New  York's  sewage  problem. 

Experiments  have  shown  that  the  amount  of  chlorine  which  it  would  be  neces- 
sary to  apply  to  settled  sewage  in  order  to  produce  a  material  reduction  in  the  dis- 
solved oxygen  required  would  be  so  great,  its  sterilizing  effects  so  powerful  and  its 
odor  so  penetrating  as  to  make  it  probable  that  the  entire  harbor  would  become  ster- 
ilized and  smell  disagreeably  of  the  disinfectant. 

Theoretically  a  powerful  oxidizing  agent,  chlorine  appears  to  be  capable  of  pro- 
ducing an  appreciable  oxidizing  effect  upon  sewage  only  in  concentrations  which  it  is 
impracticable  to  employ.  In  moderate  concentration  it  is  a  poisonous  gas  easily  sol- 
uble in  water,  from  which  it  can  be  completely  driven  only  with  difficulty. 

Hitherto  chlorine  and  hypochlorite  have  been  used  in  water  and  sewage  treatment 
only  as  disinfectants,  minute  doses  being  usually  sufficient  to  accomplish  the  desired 
end.  In  the  arts,  chlorine  compounds  are  used  extensively  for  bleaching  purposes. 
There  are  no  works  for  the  chemical  oxidation  of  sewage  now  operating  upon  this 
principle  and  it  appears  impossible  to  give  reasonable  assurance  that  the  process 
suggested  can  actually  be  carried  out.  Used  as  a  disinfectant,  the  Commission 
is  of  opinion  that  chlorine  perhaps  prepared  from  electrolyzed  sea  water  may 
be  found  to  be  of  considerable  service  in  dealing  with  certain  parts  of  New  York's 
sewage. 

The  cost  of  oxidizing  the  sewage  by  means  of  chlorine  would  be  excessive,  espe- 
cially in  view  of  the  ample  provision  which  would  have  to  be  made  for  the  preliminary 
septic  tanks  or  basins  capable  of  producing  a  non-fermenting  sludge.  It  is  not  clear 
why  the  fermentation  of  sludge  appears  to  the  author  of  the  report  to  be  a  necessary 
step  in  the  process.  If  thorough  sedimentation  could  be  provided  for  all  the  sewage 
entering  the  harbor,  it  would  seem  from  the  Commission's  researches  to  be  permis- 
sible to  dispense  with  the  oxidizing  process. 

The  idea  of  discharging  fermented  sludge  into  the  harbor  is  apparently  contrary 
to  the  federal  laws  which  have  been  enacted  for  the  protection  of  the  navigable  chan- 
nels against  shoaling. 


292 


REPORTS  OF  EXPERTS 


REPORT  OP  SAMUEL  RIDEAL 

Dr.  George  Soper, 

President,  Metropolitan  Sewage  Commission  of  New  York. 

Dear  Dr.  Soper:  Since  my  inspection  with  you  of  the  New  York  Harbor,  and 
especially  the  East  river,  on  October  2d,  I  have  read  your  two  reports  with  much  in- 
terest and  will  now  try  and  answer  the  questions  which  you  have  put  to  me  in  your 
letter  of  October  3d. 

Before  doing  so,  however,  I  should  like  to  congratulate  the  Commission  upon  the 
very  valuable  information  which  these  reports  contain,  and  the  clearness  with  which 
the  facts  have  been  marshalled ;  so  far  as  I  have  at  present  been  able  to  study  the 
problem,  I  feel  that  the  proposed  standards*  are  both  desirable  and  feasible,  and  it  is 
to  be  hoped  that  the  treatment  of  the  sewage  of  your  future  population  will  be  de- 
signed in  such  a  way  as  will  ensure  that  the  standards  will  not  be  infringed. 

You  ask  my  opinion  on  the  condition  of  the  Harbor  water  as  I  saw  it  on  my  trip 
of  inspection  on  October  2d,  and  I  must  say  that  I  was  surprised  that  a  city  claiming 
to  be  one  of  the  first  in  the  world  should  allow  such  a  disgraceful  condition  of  affairs 
to  exist  even  for  a  moment.  One  cannot  blame  the  past  for  creating  a  city  popula- 
tion on  an  island  surrounded  by  land-locked  waters,  nor  complain  of  its  rapid  devel- 
opment to  the  surrounding  shores,  but  surely  for  many  years  past  such  an  unfortunate 
condition  of  the  Harbor  waters  and  banks  of  your  great  city  should  have  prompted 
the  authorities  to  have  earnestly  tackled  this  great  blot  upon  your  civilization  earlier 
in  the  development  of  your  city.  I  understand  that  whilst  the  work  of  your  Commis- 
sion has  been  in  progress  during  the  past  few  years,  your  neighbors  in  New  Jersey,  to 
whom  the  purity  of  the  Harbor  waters  is  of  equal  importance,  have  not  joined  hands 
with  the  City  of  New  York  and  associated  themselves  with  the  desire  to  stop  the  dis- 
charge of  unpurified  sewage  and  polluting  waters  into  the  Harbor.  In  my  opinion  it 
behooves  the  two  States  to  work  hand  in  hand  at  once  in  order  to  satisfactorily  solve 
the  problem,  and  that  further  delay  must  inevitably  lead  to  serious  sanitary  troubles 
which  will  militate  against  the  life  and  well-being  and  future  prosperity,  of  not  only 
the  riparian  population,  but  of  the  whole  of  your  great  metropolis.! 

The  main  question  which  you  have  asked  me  to  consider  can  hardly  be  dealt  with 
in  a  short  report  nor  without  a  prolonged  study  of  the  main  details  chiefly  of  an  en- 
gineering character.  Assuming  a  collaboration  of  the  whole  of  the  authorities  now 
polluting  the  Harbor  waters,  I  am  of  the  opinion  that  our  present  knowledge  of  sew- 
age purification  makes  it  possible  to  sufficiently  purify  the  sewage  in  the  territory  on 
properly  selected  local  sites  so  that  the  effluent  may  be  harmlessly  discharged  into  the 
waters.  In  making  this  positive  statement  and  thus  giving  an  affirmative  answer  to 
your  question  so  definitely,  I  am  guided  by  the  evidence  which  you  have  collected, 
which  shows  that  at  the  present  time  the  waters  of  the  inner  Harbor,  as  a  whole,  have 
not  under  present  conditions  fallen  below  your  suggested  standards,  and  that  it  will 
be  possible  in  the  future  to  banish  bathing  and  oyster  culture  (as  suggested  in  your 
5th  standard)  from  any  part  of  the  Harbor  north  of  the  Narrows,  or  in  the  Arthur  Kill, 
and  to  deal  specially  with  Jamaica  Bay  and  elsewhere  where  these  two  are  practised. 

•The  Degree  of  Cleanness  Which  is  Necessary  and  Sufficient  for  the  Water.  See  the  Commission's  Report  of 
August,  1912,  Part  II,  Chapter  I,  Page  70. 

tThe  Metropolitan  Sewerage  Commission  endeavored  to  secure  the  co-operation  of  New  Jersey  in  its  work,  but 
without  result.    See  Report  of  April,  1910,  Part  I,  Chapter  I,  Page  43. 


REPORT  OF  SAMUEL  RIDEAL 


293 


We  have  then  to  recollect  that  the  problem  kept  foremost  in  a  harbor  is  not  to 
purify  the  sewage,  but  a  far  simpler  one,  i.  e.,  the  removal  of  unsightly  and  offensive 
floating  suspended  matters,  and  to  ensure  that  the  effluent  is  invisible  and  inodorous 
when  mixed  with  the  Harbor  water.  This  being  the  object  in  view,  I  believe  that  the 
removal  of  the  floating  suspended  matter  can  be  effectively  carried  out  locally  on  re- 
stricted areas  of  land  or  in  restricted  areas  of  water  at  fixed  points,  dealing  with  25 
to  30  million  gallons  of  sewage  per  24  hours,  and  therefore  by  judicious  selection  of 
sites  these  can  be  multiplied  to  deal  with  the  prospected  future  population,  and  that, 
consequently,  the  heavy  costs  involved  in  any  scheme  of  discharging  the  whole  of  the 
sewage  to  sea  at  the  ocean  entrance  to  the  Harbor  or  disposal  on  farm  land  on  sewage 
farms  on  Long  Island,  or  bacterial  treatment  on  Barren  Island,  would  be  negatived. 

When  you  ask  me  to  discuss  the  methods  of  oxidizing  sewage  you  mean  "how  can 
the  waters  of  New  York  Harbor  be  kept  half  saturated  with  oxygen  as  at  present." 

It  would  seem  at  first  sight  that  additional  oxygen  or  air  could  be  directly  ap- 
plied to  the  Harbor  waters  to  comply  with  this  requirement,  and  I  understand  that  a 
method  of  forced  aeration  to  accomplish  this  object  has  been  seriously  discussed.  But 
I  point  out  further  that  the  rate  of  absorption  of  oxygen  from  air  is  slow,  and  that 
even  by  agitation  the  maximum  amount  of  oxygen  capable  of  being  absorbed  by 
sewage  is  approximately  the  same  as  that  which  can  be  absorbed  by  water,  and  we 
have  now  the  fact,  as  well  shown  in  your  report,  that  the  present  flow  of  sewage  is 
absorbing  gradually  at  the  surface  the  oxygen  of  the  air  over  the  Harbor  waters  and, 
in  addition,  is  consuming  the  dissolved  oxygen  from  these  waters  to  the  extent  of 
nearly  half. 

In  reference  to  your  first  question,  as  to  other  ways  of  oxidizing  the  sewage  than 
by  biological  methods,  i.  e.,  by  the  use  of  chemicals,  the  following  are  the  only  ones 
that  have  practically  been  found  available: 

1.  Manganates  or  Permanganates.  The  report  of  the  British  Commission  of 
1882  on  the  effects  of  the  discharge  of  the  sewage  of  London  into  the  Thames  found 
that  it  was  possible  to  thoroughly  deodorize  (and  presumably  efficiently  sterilize) 
sewage  by  permanganate  and  sulphuric  acid  (giving  ozonized  oxygen)  either  before 
or  after  the  removal  of  the  suspended  matter  by  precipitation  (Vol.  XI,  p.  142). 
Sodium  manganate,  as  a  cheaper  salt,  was  used  for  the  London  sewage  from  1884  to 
1894  by  introducing  it  into  sewers  at  different  points ;  being  strongly  alkaline,  it  dis- 
engaged ammonia,  which  was  neutralized  by  acid  treatment  at  the  outfall.  The  process 
was  expensive,  and  was  generally  abandoned  in  favor  of  bacterial  methods,  or  lime- 
iron-alumina  precipitations. 

There  is  no  doubt  that  the  manganese  oxides  in  the  sludge  act  as  carriers  of 
oxygen  and  promote  its  oxidation,  and  Adeney  in  1894  founded  a  process  of  purifica- 
tion on  this  fact.  It  was  hoped  that  the  manganese  could  be  economically  recovered 
from  the  sludge,  but  this  has  not  yet  been  done. 

2.  Oxidized  Compounds  of  Chlorine  are  much  more  economical.  My  experience 
at  Guilford  is  well  known,  in  which  I  found  a  great  advantage  in  treating  the  raw 
sewage  direct  with  an  electrolyzed  salt  solution,  called  "oxychloride,"  containing 
sodium  hypochlorite,  instead  of  using  ordinary  precipitants  of  the  lime,  iron  and 
alumina  class.  The  benefits  noticed  were  (1)  disappearance  of  nuisance,  (2)  reduc- 
tion of  volume  of  sewage,  (3)  stability  of  sludge  and  effluent. 

In  other  places  "chloros"  (a  chemically  prepared  sodium  hypochlorite),  and 
bleaching  powder  (calcium  compound),  have  been  used  with  similar  success. 


294 


REPORTS  OF  EXPERTS 


The  proportion  of  these  chlorine  oxidizers  can  be  easily  controlled  so  that  the 
effluent  should  be  sufficiently  sterilized  and  should  be  harmless,  securing  in  the  terms 
of  your  letter: 

(a)  "absence  of  odor," 

(b)  "restricted  areas  of  land," 

(c)  "freedom  from  substances  poisonous  to  fish." 

At  the  same  time  the  matter  is  a  question  of  expense. 

The  hypochlorite  treatment  involves  no  "heavy  expense  for  pumping,"  but  the 
cost  of  the  chemicals  if  applied  to  such  large  volumes  of  raw  sewage  would  be  exceed- 
ingly great. 

From  this  arises  the  necessity  of  applying  mechanical  and  bacterial  processes  in 
the  first  stage,  and  reserving  the  oxidizing  agent  as  a  finisher.  To  quote  an  example 
from  my  own  practice,  a  raw  sewage  required  50  parts  per  million  of  available 
(active)  chlorine  for  sterilization  of  pathogenic  organisms;  after  passage  through  a 
septic  tank  about  half  (24)  sufficed;  and  when  passed  afterwards  through  porous 
gravel,  10  to  5  parts  did  the  same  work,  proving  that  it  is  better  to  apply  a  prelim- 
inary treatment. 

I  cannot  do  better  than  quote  from  my  book  on  "Sewage  and  Its  Purification," 
third  edition,  p.  188 : 

The  simple  treatment  of  raw  sewage  by  means  of  a  septic  tank  and  then  addi- 
tion of  the  solution  would  be  sufficient  for  a  large  number  of  cases  where  the 
organic  purity  was  of  less  importance  than  the  removal  of  pathogenic  organisms, 
as  in  localities  close  to  shellfish  gathering-grounds  or  watercress  beds.    For  both 
of  these,  and  particularly  for  vegetables,  complete  organic  purification  might  be 
a  disadvantage,  as  depriving  them  of  food.    In  places  where  open  septic  tanks 
had  been  objected  to  on  account  of  suggested  nuisance,  closed  tanks  could  be 
adopted  of  a  rather  smaller  size  than  usual,  the  solution  being  added  in  a  covered 
carrier  with  baffle  plates  as  the  effluent  passed  out,  with  a  certainty  of  removing 
all  objectionable  odors.    If  existing  tanks  are  divided  by  a  party  wall  into  two 
unequal  chambers;  in  the  first  of  say  twenty  hours'  dry  weather  capacity,  the 
anaerobic  preparation  could  go  on  as  at  present;  while  in  the  second,  of  say  four 
hours'  capacity,  the  chlorine  solution  would  be  added  in  sufficient  quantity  to 
cause  the  remaining  suspended  solids  to  subside  in  a  more  or  less  sterilized  con- 
dition, and  the  effluent  to  be  free  from  smell  and  objectionable  organisms.  The 
cost  and  space  required  for  primary,  secondary  and  tertiary  beds  would  in  this 
way  be  saved.    I  believe  that  the  method,  in  the  case  of  seaside  towns  and  those 
discharging  into  estuaries,  would  greatly  contribute  to  local  healthy  conditions, 
and  would  ensure  the  absence  of  unsightly  sewage  matter  on  the  shores. 
In  comparing  quantities  the  sewage  in  the  United  States  being  generally  more  dilute 
than  that  in  Europe  will  require  as  a  rule  a  smaller  amount  of  oxidant.  At  the  same 
time  there  will  be  a  greater  necessity  for  sterilisation,  since  there  will  be  a  larger  vol- 
ume of  water  fouled.   The  map*  shows  an  enormous  bacterial  increase  from  the  upper 
parts  of  East  river  and  the  Hudson  down  to  the  city.    The  greater  number  of  these 
organisms  act  as  scavengers,  but  a  smaller  proportion  are  pathogenic,  derived  from 
the  inhabitants  or  animals.    It  is  fortunate  that  species,  like  Bacillus  typhosus,  are 
more  easily  killed  by  chemical  treatment  than  harmless  other  kinds,  like  B.  subtilis, 

•  See  the  Commission's  Report  of  August,  1912,  Part  III,  Chapter  II,  Pages  264-6. 


REPORT  OF  SAMUEL  RIDEAL 


295 


which  are  actually  useful  in  breaking  up  cellulose  and  organic  debris  and  do  their 
work  naturally  in  sewers  and  in  a  septic  tank. 

With  reference  to  your  second  question  as  to  whether  the  presence  of  sludge  on 
the  harbor  bottom  accounts  for  the  exhaustion  of  oxygen  from  the  water. 

Sludge  absorbs  oxygen  in  variable  proportions  according  to  its  composition,  but 
its  action,  as  a  sediment,  on  a  liquid  above,  particularly  when  the  latter  is  in  motion 
as  in  river  channels,  is  very  slow.  Therefore  I  agree  with  your  Commission  as  to  the 
importance  of  the  sludge,  but  consider  that  the  aqueous  liquid  of  the  sewage  must  be 
more  responsible  for  the  exhaustion  of  oxygen. 

In  regard  to  your  remark  that  "the  processes  must  be  applicable  to  not  less  than 
25  to  30  million  gallons  for  each  of  many  unit  plants,"  I  see  no  reason  why  units  of 
this  character  could  not  be  adopted  as  it  would  be  an  advantage  to  have  a  separate 
treatment  at  each. 

If  not  possible  to  secure  space  for  the  septic  or  sludge  digesting  tanks  on  land, 
they  could  be  erected  in  the  water  along  Manhattan  Island  and  in  other  places  similar 
in  form  to  a  large  swimming  bath,  with  a  sterilizing  equipment  by  the  side.  A  covered 
tank  would  prevent  any  nuisance,  and  the  decomposition,  being  principally  anaerobic, 
as  we  have  found  in  septic  tanks,  is  not  attended  by  absorption  of  oxygen,  and  the 
sludge,  having  attained  its  main  decomposition  without  oxygen,  could  be  discharged 
with  no  fear  of  absorbing  much  oxygen  afterwards. 

The  effluent  could  then  be  treated  at  the  outfall  piers  with  a  small  quantity  of 
oxidizer  and  in  this  way  hardly  any  pumping  would  be  required  if  the  sites  were 
selected  with  this  object  in  view. 

Estimation  of  the  Amount  of  Chlorine  Required 

Referring  to  p.  20  of  the  Metropolitan  Sewerage  Commission's  Report  of  August, 
1912,  and  calculating  the  cubic  feet  into  gallons  (1  cub.  ft.  =  7.5  U.  S.  Gallons),  it 
will  be  seen  that  the  quantity  of  water  which  ebbs  and  flows  through  the  Narrows 
may  be  taken  as  90,000  million  gallons  per  tide.  The  excess  of  seaward-moving  water 
over  that  which  returns  is  estimated  at  9,750  million  gallons  per  tide.  Of  this  8,250 
million  gallons  is  accounted  for  by  land  water  coming  down  from  the  Hudson  and  750 
million  gallons  "flows  toward  the  sea  from  the  tidal  actions  in  the  East  river." 
These  last  factors  account  together  for  9,000  million  gallons,  and  leave  an  excess  of 
750  million  gallons  per  tide  which  is  mainly  contributed  in  about  equal  quantities  by 
the  sewage  and  local  drainage  entering  the  Harbor.  This  will  be  1,500  million  gallons 
per  24  hours. 

From  the  fact  that  the  waters  entering  from  above  and  from  below  contain  an 
average  of  6  cubic  centimeters  per  liter  of  dissolved  oxygen,  whereas  the  water  in  the 
inner  harbor  must  not  in  the  future  contain  less  than  3  cubic  centimeters  per  liter,  it 
follows  that  a  reduction  of  dissolved  oxygen  of  3  c.c.  per  liter  is  permissible.  At  the 
same  time  atmospheric  oxygen  is  dissolving  in  the  water  to  replace  that  which  has 
disappeared,  so  that  the  actual  is  greater  than  the  apparent  absorption. 

From  experiments  I  have  made  on  the  absorption  of  atmospheric  oxygen  by 
waters  (Analyst,  London,  August,  1901),  I  notice  that  it  is  very  slow  unless  circula- 
tion interferes. 

Shallow  layers  (3  inches  deep)  of  the  following: 

A.  Water  vigorously  boiled  in  a  flask  for  two  hours ; 


296  REPORTS  OF  EXPERTS 

B.  Sewage  similarly  boiled,  with  addition  of  boiled  water  to  maintain  the  volume ; 

O.  Raw  sewage ; 

were  kept  in  a  quiet  room  and  the  dissolved  oxygen  determined  at  intervals.  The 
results  are  given  in  the  following  table: 


TABLE  XLIII 


A. 

Boiled  Water 

B. 

Boiled  Sewage 

C. 

Raw  Sewage 

Hours 

Temp. 
°C. 

C.C.  per 
Liter 

Dissolved 
Oxygen 
Found 

Roscoe's 
Maximum 

at  the 
Tempera- 
ture 

Percent- 
age of 
Satura- 
tion 

C.C.  per 

Liter 
Dissolved 
Oxygen 
Found 

Roscoe's 
Maximum 

at  the 
Tempera- 
ture 

Percent- 
age of 
Satura- 
tion 

C.C.  per 
Liter 

Dissolved 
Oxygen 
Found 

Roscoe'a 
Maximum 

at  the 
Tempera- 
ture 

Percent- 
age of 
Satura- 
tion 

1 

2 

3i... 

5 
11 
25 

14.0 
14.5 
15.5 
14.0 
14.5 
14.5 

3.17 
3.81 
4.41 
4.64 
5.69 
6.71 

7.12 
7.04 
6.89 
7.12 
7.04 
7.04 

44.5 
54.1 

64.0 
68.0 
80.8 
95.3 

3.12 
3.23 
4.12 
4.70 
5.13 
6.22 

7.12 
7.04 
6.89 
7.12 
7.04 
7.04 

43.8 
45.9 
59.8 
66.0 
72.8 
88.3 

3.16 
3.82 
4.26 
4.42 
4.05 
3.0 

7.12 
7.04 
6.89 
7.12 
7.04 
7.04 

44.4 
54.2 
61.8 
62.0 
57.5 
42.6 

The  liquids  deprived  of  gases  have,  according  to  the  well-known  rule,  absorbed  the 
gas  (in  this  case  air)  very  rapidly  at  first,  so  that  in  the  first  hour  about  half  satura- 
tion was  reached.  Afterwards  the  absorption  was  very  slow,  and  was  not  quite  com- 
pleted, even  in  those  thin  layers  in  25  hours. 

That  the  boiled  sewage  behaved  in  nearly  the  same  way  as  ordinary  water  shows 
the  effect  of  the  absence  of  living  organisms. 

In  the  raw  sewage  the  absorption  is  at  first  normal,  but  after  5  hours  the  con- 
sumption of  oxygen  by  fermentations  overpowers  the  absorption  from  the  air,  and  the 
amount  in  solution  sinks,  till  in  25  hours  it  falls  again  to  half  saturation.  This  shows 
how  rapid  is  the  change  when  it  once  starts.  Adeney  observed  that  a  water  of  a  reser- 
voir contained  at  5  feet  depth  5.71  c.c.  of  oxygen  per  liter,  at  20  ft.  depth  only  2.0,  due 
to  bacterial  action. 

The  saturation  amount  of  dissolved  oxygen  found  in  the  New  York  saline  waters, 
namely  6  c.c.  per  liter,  is  equivalent  to  8.6  parts  per  million  of  oxygen  by  weight.  If 
in  the  Harbor  it  were  reduced  to  3  c.c,  4.3  parts  per  million  parts  would  be  abstracted 
by  the  combined  sewage  and  drainage.  This  will  correspond  to  36  pounds  of  oxygen  for 
each  million  U.  S.  gallons.  Hence  the  total  1,500  million  gallons  of  sewage  and  drain- 
age will  have  absorbed  from  its  own  volume  54,000  lbs.  or  24.1  tons  of  oxygen.  But 
inasmuch  as  the  water  coming  down  is  equal  to  18,000  million  gallons  per  24  hours, 
and  this  has  been  equally  denuded  of  oxygen,  the  total  quantity  of  oxygen  absorbed  is 

24.1X18000  „  ,    .  .  „ 

 J^qq  289.2  tons,  or  in  other  words,  the  sewage  and  drainage  are  mixed  with 

twelve  times  their  volume  of  river  water  which  it  has  half  robbed  of  oxygen.  To 
entirely  replace  this  deficit  would  require  the  oxidizing  power  of  its  equivalent 
(8:35.4),  or  1,280  tons  of  "available  chlorine."  But  such  a  complete  oxidation  is  not 
necessary  because  ( 1 )  it  is  considered  that  the  state  of  the  water  in  the  Harbor  is  not 
at  present  objectionable,  and  will  not  become  so  unless  there  is  a  reduction  of  the 
dissolved  oxygen  below  the  present  figure  of  3  c.c.  per  liter  and  (2)  chlorine  has  a 
sterilizing  action  beyond  its  oxidizing  power  and  produces  stable  compounds. 


REPORT  OF  SAMUEL  RIDEAL 


297 


Points  that  I  have  already  noticed  are: 

(1)  The  bottom  layer  of  sludge  absorbs  oxygen  very  slowly  from  the  mass  of 
water  above. 

(2)  The  replacement  of  oxygen  by  solution  from  the  atmosphere  at  the  surface 
is  also  slow. 

(3)  These  two  actions  tend  to  counterbalance  one  another,  so  that  the  loss  of 
dissolved  oxygen  is  essentially  due  to  changes  occurring  in  the  liquid  caused  by  its 
organisms  living  on  its  organic  suspended  and  dissolved  matter. 

Obviously,  screening,  and  if  possible,  sedimentation,  will  remove  the  greater  part 
of  the  suspended  matter  and  reduce  the  deposition  in  the  Harbor.  Subsequent  chlo- 
rine treatment  of  the  effluent,  besides  destroying  pathogenic  organisms,  will  prevent 
offensiveness  and  limit  the  abundance  of  such  organisms  as  cause  deoxidation.  I 
believe  the  sludge  after  fermentation  may  be  discharged  under  water  without  offense 
and  pass  to  the  sea  along  with  the  natural  silt  of  the  river. 

At  Philadelphia  it  was  found  that  screened  sewage  treated  with  150  lbs.  of  dry 
bleach  (chloride  of  lime)  per  million  gallons,  equal  to  6  parts  per  million  of  avail- 
able chlorine — or  screened  and  settled  sewage  treated  with  105  lbs.  of  bleach  [4  parts 
per  million  available  chlorine)  was  economically  disinfected  (Report  Philadelphia 
Bureau  of  Surveys,  1911.  pp.  127-12SL  Calculated  on  this  basis  the  1,500  million 
U.  S.  gallons  of  New  York  sewage  and  drainage  would  require  in  tons  per  21  hours  (the 
drainage  is  here  assumed  to  be  brought  to  the  sewers  and  to  need  similar  treatment )  : 


TABLE  XLIV 


Available 

Chloride  of  Lime  of 

Chlorine 

33  %  Strength 

For  Screened  Sewage  

27.9 

S3  7 

For  Screened  and  Settled  Sewage  

19.5 

53  6 

An  estimate  of  the  New  York  population  at  6  millions  and  the  sewage  at  800 
million  gallons  gives  133  gallons  per  head.  In  England  we  have  about  30  gallons  per 
head — so  that  the  comparative  dilution  is  about  one  to  four,  and  a  less  quantity  of 
oxidizer  would  be  required  than  we  have  found  necessary  in  England. 

Assuming  the  sewage  freed  from  suspended  matters  by  screening  and  sedi- 
mentation in  a  septic  or  Imhof  tank  we  may  therefore  take  one-fourth  of  24,  the  fig- 
ure I  obtained  at  Guildford,  and  thus  arrive  at  6  parts  per  million  as  the  quantity 
likely  to  prove  effectual. 

Provision  fob  Increase  of  Population 

It  is  supposed  that  the  present  population  of  6  millions  will  increase  by  1910  to 
9  millions,  which  will  add  about  one-half  to  the  present  effect  of  the  sewage.  If  the 
existing  position  is  pronounced  satisfactory,  it  can  be  kept  the  same  by  adding  a 
chlorine  agent  in  progressively  increasing  amounts  to  balance  the  advance  of  3  mil- 
lions in  population.  Then  if  we  take  our  previous  figures  for  the  quantity  of  chlorine 
agent  estimated  for  6  million  people,  excluding  drainage,  this  addition  would  pro- 
gressively reach  by  1910,  until  the  additional  volume  of  sewage  to  be  treated  will  be 
100  million  gallons  or  in  tons  per  21  hours: 


298  REPORTS  OF  EXPERTS 

TABLE  XLV 


Available 

Chlroide  of  Lime  of 

Sewage 

Chlorine 

33%  Strength 

7.4 

22.2 

5. 

15. 

Calculations  show  that,  in  most  places,  the  purification  of  sewage  by  means  of 
chlorine  would  be  cheaper  than  purification  by  aeration.  Now  chlorine  can  be  added 
in  the  following  forms : 

A.  As  chlorine  gas,  the  by-product  of  electrolytic  alkali  works.  This  would  only 
be  economical  if  there  happened  to  be  alkali  works  situated  quite  close  to  the  pro- 
posed sewage  treatment  works. 

B.  As  bleaching  powder,  made  from  the  gaseous  chlorine  by-product  of  alkali 
works  situated  at  a  distance.  These  alkali  works  would  probably  be  at  a  place  where 
power  is  cheap,  and  bleaching  powder  is  the  best  form  in  which  chlorine  can  be  trans- 
ported. At  New  York  it  would  probably  be  possible  to  obtain  bleaching  powder  from 
Niagara  where  power  is  very  cheap;  but  it  must  be  remembered  that  it  is  necessary 
to  pay  freight  on  the  bleaching  powder,  which  consists,  only  to  the  extent  of  about  one- 
third,  of  active  chlorine. 

C.  As  sodium  hypochlorite,  prepared  in  New  York  by  the  electrolysis  of  sodium 
chloride  solutions.  For  this  purpose,  power  derived  from  coal  must  be  used,  and  this 
will  be  more  costly  than  power  from  Niagara.  At  the  same  time  the  fact  that  the  sub- 
stance is  prepared  on  the  spot  saves  the  cost  of  its  transport. 

As  a  source  of  sodium  chloride,  it  would  be  possible  to  utilize  either — 

1.  The  water  obtained  from  the  river  at  the  proposed  treatment  station,  three 
parts  of  which  contains  two  parts  of  sea  water,  or 

2.  Solid  rock  salt  obtained  from  the  nearest  salt  field. 

At  first  sight  the  former  proposal,  which  utilizes  sodium  chloride  that  can  be  ob- 
tained free  of  charge,  would  seem  the  more  economical.  But  this  is  not  necessarily 
the  case.  The  plant  required  to  make  hypochlorites  from  a  dilute  chloride  solution 
would  have  to  be,  ceteris  paribus,  far  larger  than  a  form  employing  strong  solutions. 
The  capital  cost  and  maintenance  and  depreciation  charges  would  thus  be  increased, 
and  most  processes  work  actually  more  efficiently  when  high  concentrations  are  em- 
ployed. It  is  more  difficult  to  fix  beforehand  the  cost  of  making  hypochlorites  from 
sea  water  since,  up  to  date,  most  plants  have  been  designed  to  use  solutions  containing 
between  5  and  15  per  cent,  of  sodium  chloride.  If  it  were  determined  to  use  these 
strong  solutions  they  could  be  made  by  dissolving  rocksalt  in  the  river  water  which 
already  contains  some  sodium  chloride;  this  would  economize  rocksalt.  The  cost  of 
production  by  processes  using  solid  rocksalt  as  the  source  of  chlorine  would  be  easier 
to  calculate  without  special  experiments,  since  there  are  more  data  available  as  to 
actual  working  experience  in  these  cases.  On  the  other  hand,  where  the  issues  are  so 
important,  it  would  be  worth  while  to  investigate  specially  processes  using  dilute  solu- 
tions and  to  consider  if  these  could  be  further  improved. 

It  would  be  possible,  if  accurate  information  as  to  the  cost  of  power,  salt,  bleach- 
ing powder  and  labor  in  New  York  were  provided,  to  give  a  definite  opinion  as  to 
whether  B,  C  (1)  or  C  (2)  would  furnish  the  cheaper  means  of  treating  the  sewage. 
It  would  doubtless  be  possible  for  you  to  find  out  whether  there  happens  to  be  any 
factory  on  the  spot  which  would  be  ready  to  dispose  of  its  surplus  chlorine,  as  such, 
for  treatment  of  part  of  the  sewage  according  to  proposal  A. 


REPORT  OF  SAMUEL  RIDEAL 


299 


Treatment  by  Forced  Aeration 

The  report  by  Colonel  Black  and  Professor  Phelps  in  1911  draws  attention  to  the 
benefit  of  a  "short  period  septic  action,"  with  which  I  agree,  but  I  do  not  consider  that 
subsequent  forced  aeration  in  a  deep  tank  would  give  the  improvement  they  anticipate. 
The  method  has  been  often  previously  proposed  under  the  hope  of  "intensified  oxida- 
tion," but  has  not  succeeded  because  atmospheric  oxygen  dissolves  and  acts  so  slowly. 

The  amount  of  oxygen  forced  in  artificially  at  considerable  expense  can  only  raise 
the  oxygen  content  to  its  solubility  of  7  c.c.  per  liter  at  any  one  time,  and  this  would 
have  to  be  repeated  about  12  times  to  equal  the  quantity  of  dissolved  oxygen  now  sup- 
plied by  the  river  waters.  A  million  U.  S.  gallons  can  only  dissolve  about  .037  ton  of 
oxygen  so  that  the  800  million  gallons  can  take  up  at  one  saturation  nearly  30  tons. 

The  report  concludes  that  an  air  consumption  of  0.1  cubic  feet  per  gallon  would 
be  sufficient  under  the  above  conditions.  As  air  contains  about  one-fifth  of  its  volume 
of  oxygen,  this  will  be  15  volumes  of  sewage  to  4  volumes  of  oxygen,  and  is  equivalent 
to  38  repeated  saturations  even  if  the  oxygen  were  completely  taken  up  each  time. 
We  have  no  means  of  ascertaining  how  rapid  this  absorption  will  be  locally — it  must 
certainly  take  several  days,  and  obviously  involves  the  sewage  remaining  in  the  Harbor 
more  than  three  times  longer  than  it  does  at  present  as  the  rate  of  absorption  grad- 
ually becomes  slower. 

On  this  estimate  15  liters  of  sewage  would  require  4  liters  of  oxygen  equal  to 

5.72  grams,  and  1,000  liters  of  sewage  would  need  100^X5. 7w  _       grams  0XVgen 

15 

That  is,  a  million  grams  of  sewage  corresponds  to  3S1  grams  of  oxygen,  or  a  million 

tons  of  sewage  to  381  tons  of  oxygen. 

If  1  ton  =  269  U.  S.  gallons,  it  is  evident  that  a  million  tons  =  269  million  U.  S. 

gallons,  and  the  present  800  million  TJ.  S.  gallons  of  sewage  per  day  would  require 

to  attain  an  air-consumption  of  0.1  cubic  feet  per  gallon : 

381X800     11on,  . 
 =  1130  tons  of  oxvgen. 

269 

This  would  be  theoretically  possible,  but  would  involve  four  difficulties : 

(1)  Holding  up  the  sewage  for  38  days,  or  such  time  as  38  saturations  take,  in- 
cluding: 

(2)  Tankage  for  38X800  =  30,400  million  gallons  of  sewage,  or  such  smaller 
tankage  as  would  ensure  sufficient  time  for  the  above  absorption  to  take  place. 

(3)  Power  to  keep  the  air  continuously  bubbling  through. 

(4)  Almost  certain  nuisance  from  the  smell  carried  off  the  sewage  by  the  cur- 
rent of  air. 

Amount  op  the  Present  Natural  Aeration  by  River  Water 

If  the  water  coming  down  the  Hudson,  etc.,  contains  6  c.c.  of  oxygen  per  liter, 
this  will  be  8.6  parts  per  million  by  weight,  corresponding  to  8.6  tons  of  oxygen  per 
million  tons  of  river  water.  A  ton  of  water  being  equivalent  to  269  U.  S.  gallons,  the 
proportion  is  8.6  tons  of  oxygen  in  269  million  U.  S.  gallons  of  river  water. 

The  water  coming  down  is  18,000  million  U.  S.  gallons  per  24  hours.  Therefore 
the  total  amount  will  be  in  tons : 

18.000  million  gallons X 8.6  ,         .  ,        ,  ,  ,  0(  ,  , 
 2  a —  —  575  tons  of  oxvgen  brought  down  per  24  hours  by  the 

269  million  gallons 
river  waters. 


300 


REPORTS  OF  EXPERTS 


The  English  Royal  Commission  (Fifth  Report,  p.  234)  prescribes  a  maximum 
absorption  of  oxygen  by  a  satisfactory  effluent  as  0.5  parts  of  oxygen  by  weight  per 
100,000  parts  by  weight  of  effluent  in  24  hours,  equal  to  5  tons  of  oxygen  per  million 
tons  of  effluent.     The  575  tons  of  oxygen  mentioned  above  would  therefore  supply 
575 

 =  115  million  tons  of  purified  English  sewage  effluent,  but  we  have  seen  that 

5 

there  is  no  necessity  for  demanding  such  a  standard  of  effluent  for  these  waters. 

At  present  about  100  parts  of  oxygen  per  million  is  required  by  the  sewage  or 
twenty  times  the  amount  required  by  a  first-class  English  effluent,  and  the  1,500  mil- 
lion gallons  of  New  York  sewage  and  drainage,  by  absorbing  the  above  quantity  of 
100  parts  of  oxygen  per  million,  might  rob  the  rivers  of  292  tons,  which  we  have  seen 
is  half  the  total  oxygen  in  the  rivers  as  measured  by  its  present  volume  and  oxygen 
content. 

An  average  rate  at  which  oxygen  is  absorbed  and  consumed  has  been  shown  ex- 
perimentally by  Adeney  to  equal  57.5  c.c.  per  liter  in  24  hours  by  polluted  waters  or 
in  48  hours  6*6  c.c,  which  is  the  quantity  of  oxygen  in  11  times  its  volume  of  saturated 
water.  We  know  from  the  quantity  of  dissolved  oxygen  in  the  Hudson  that  half  its 
oxygen  is  now  robbed  by  the  present  sewage,  and  that  the  volume  ratio  is  1  to  25  for 
the  sewage  or  1  to  12  including  surface  water  and  drainage.  If  the  sewage  has  now 
absorbed  the  whole  of  the  oxygen  from  12  times  its  volume  of  fully  aerated  water, 
this  is  in  fair  agreement  with  Dr.  Adeney's  experimental  figures  and  shows  the  futil- 
ity of  aeration  unless  repeated  twelve  or  more  times  during  the  whole  of  the  period  of 
absorption. 

I  have  seen  the  estimated  approximate  cost  of  the  works  for  the  disposal  of  the 
sewage  upon  farm  land,  and  for  the  disposal  to  sea,  and  these  show  capital  costs 
much  higher  than  those  for  local  small  sedimentation  tanks  to  remove  the  solids  and 
for  plant  for  chlorine  treatment.  It  would  appear  that  the  saving  in  the  capital 
charges  would  more  than  cover  the  working  expenses  of  chlorine  treatment,  even  as- 
suming that  the  working  expenses  of  the  former  methods  are  small. 

It  seems,  therefore,  desirable  that  the  chlorine  treatment  should  have  serious 
consideration,  and  I  recommend  that  detailed  plans  and  estimates  be  prepared  on 
these  lines,  viz. : 

(1)  Preliminary  screening  and  sedimentation  to  produce  a  non-fermenting  sludge 
which  can  be  discharged  into  the  Harbor  waters  separately  without  robbing  them  of 
any  dissolved  oxygen,  and 

(2)  A  chlorine  treatment  of  the  clarified  effluent  to  such  an  extent  as  will  ensure 
the  proposed  minimum  standard  of  3  c.c.  of  dissolved  oxygen  per  liter  being  main- 
tained throughout  the  whole  of  the  Harbor  waters. 

(Signed)       Samuel  Rideal. 

November  7,  1912. 


REPORT  OF  SAMUEL  RIDEAL 


301 


SECTION  III 

PURIFICATION  WHICH  CAN  BE  EFFECTED  BY  SETTLING  BASINS  AND 
A  REPORT  BY  KARL  IMHOFF  UPON  THE  USE  OF  EMSCHER 
TANKS  IN  PURIFYING  NEW  YORK  HARBOR 

Sedimentation  is  a  standard  form  of  sewage  treatment  which  the  Commission  has 
recommended  strongly  in  connection  with  some  of  its  projects  for  the  preparation  of 
New  York's  sewage  before  discharge  into  the  tidal  waters.  It  is  the  method  of  treat- 
ment proposed  for  the  sewage  after  collection  to  the  large  central  stations  at  Ward's 
Island,  Classon  Point,  Tallman's  Island  ^and  the  Ocean  Outlet  Island.  Its  applica- 
tion locally  as  a  general  procedure  for  the  sewage  of  Manhattan  and  Brooklyn,  pre- 
paratory to  discharging  the  effluent  into  the  inner  harbor,  is  a  subject  which  has  re- 
ceived much  study. 

Sedimentation  is  accomplished  in  settling  basins  in  which  those  suspended  solids 
which  are  capable  of  subsiding  from  sewage  are  deposited  when  brought  to  a  state 
of  comparative  rest.  The  rate  of  deposit  is  such  that,  to  be  effective,  the  capacity  of 
the  basins,  which  are  sometimes  called  tanks,  must  be  sufficient  to  accommodate  the 
flow  for  one  or  two  hours.  With  some  types  of  basin,  additional  capacity  is  necessary 
in  order  to  provide  that  some  may  be  emptied  for  cleaning  out  the  deposits. 

Types  of  Tanks 

Settling  basins  are  of  various  types  and  they  are  put  to  different  uses  according 
to  the  composition  of  the  sewage  which  has  to  be  dealt  with,  the  area  and  location  of 
the  land  available,  the  facility  with  which  the  resulting  sludge  can  be  disposed  of 
and  the  condition  desired  for  the  sewage,  especially  with  respect  to  decomposition. 

The  earliest  tanks  were  large,  shallow  and  rectangular,  and  they  received  their 
sewage  at  one  end  and  permitted  it  to  flow  out  at  the  other.  Baffles  were  occasion- 
ally constructed  to  provide  for  a  uniform  rate  of  flow,  and  the  provisions  for  applying 
and  withdrawing  the  sewage  were  intended  to  afford  the  best  opportunity  for  deposi- 
tion to  take  place.  The  tanks  were  cleaned  by  drawing  off  the  sewage  and  sending 
men  with  boots  and  squeegees  to  force  the  sludge  to  the  proper  outlets.  There  are 
many  large  installations  of  tanks  built  upon  this  principle,  some  of  which  are  covered 
and  some  open.    Works  built  upon  this  principle  are  at  London  and  Glasgow. 

A  more  recent  type  of  settling  basin  gives  the  tank  approximately  the  form  of  a 
ship's  hull,  the  narrower  shape  and  greater  depth  being  intended  to  favor  uniformity 
of  flow  and  better  deposition  and  the  shape  of  the  bottom  so  facilitating  the  removal 
of  sludge  that  little  or  no  hand  labor  is  required. 


302  *  REPORTS  OF  EXPERTS 

Still  greater  provision  is  afforded  for  the  collection  and  removal  of  deposits  by 
making  the  tanks  deep  and  with  conical  bottoms.  The  removal  of  the  deposits  is  in 
this  case  effected  by  pumping  or  by  the  pressure  of  the  overlying  sewage  and  without 
the  necessity  of  emptying  the  tanks.  The  Dortmund  and  Emscher  tanks  are  of  this 
type.  Owing  to  the  fact  that  deep  tanks  have  but  recently  been  invented,  there  are 
few  practical  examples  of  them  in  existence,  but  many  have  recently  been  put  under 
construction  and  there  will  soon  be  numerous  installations,  some  of  them  of  large  size. 

Sedimentation  Period  and  Efficiency 

The  period  of  time  provided  for  the  settlement  of  the  suspended  solids  in  sedi- 
mentation basins  may  be  many  hours,  in  which  event  the  sewage  with  its  sludge  un- 
dergoes a  putrefactive  change  known  as  the  septic  process.  It  was  once  supposed  that 
septic  tanks  were  capable  of  liquefying  all  of  the  suspended  matter  of  sewage,  but 
experience  has  shown  that  their  capacity  in  this  respect  was  at  first  greatly  over- 
rated. Few  septic  tanks  have  been  built  for  the  treatment  of  large  quantities  of  sew- 
age within  recent  years. 

The  use  of  chemicals  in  connection  with  settling  basins  affords  a  means  of  has- 
tening and  making  more  complete  the  deposition  of  the  solid  and  semi-solid  materials 
which  the  sewage  contains,  but  this  useful  result  is  accomplished  at  some  expense 
and  with  the  inconvenience  of  producing  large  volumes  of  sludge. 

The  efficiency  of  settling  basins  depends  partly  upon  the  period  of  time  which 
they  afford  for  the  suspended  matters  to  deposit  and  partly  upon  the  condition  of 
the  sewage  with  respect  to  freshness.  The  suspended  solids  can  most  readily  be 
removed  before  the  sewage  has  passed  through  pumps  or  been  subjected  to  the  com- 
minuting actions  which  occur  in  passing  long  distances  through  the  sewers. 

If  the  period  of  time  afforded  for  sedimentation  is  too  short,  the  purification 
effected  will  not  warrant  the  cost  of  the  works.  Experiment  on  a  comparatively  large 
scale  is  desirable  in  order  to  determine  the  optimum  period  to  provide.  In  the  ab- 
sence of  definite  information,  it  is  necessary  to  be  guided  by  the  experience  of  such 
cities  as  have  had  occasion  to  deal  with  sewage  of  a  composition  similar  to  that  for 
which  provision  must  be  made. 

Such  experiments  as  the  Commission  has  been  able  to  make  with  New  York's 
sewage,  and  such  experience  as  has  been  gained  elsewhere  with  sewage  of  similar 
composition  indicates  that  the  optimum  period  of  time  to  provide  for  the  sedimenta- 
tion of  New  York's  sewage  would  be  two  hours,  this  allowance  to  be  based  on  the 
average  rate  of  dry-weather  flow.  Under  these  circumstances,  settling  basins  should 
be  able  to  remove  about  60  per  cent,  of  the  suspended  solids,  of  which  one-half  would 


REPORT  OF  KARL  IMHOFF  303 

be  organic  matter  and  capable  of  putrefaction.  By  the  addition  of  chemicals,  the 
efficiency  could  be  increased  so  as  to  remove  85  per  cent,  of  suspended  matter  and 
50  per  cent,  of  organic  matter.  As  compared  with  screens,  such  as  experience  indi- 
cates could  be  employed  in  New  York  without  undue  refinement  and  difficulty  with 
operating  details,  sedimentation  would  be  about  four  times  as  effective  as  screening. 

One  advantage  of  chemical  precipitation  lies  in  the  fact  that  it  can  be  discon- 
tinued at  any  time  and  a  saving  in  cost  of  operation  effected  when  weather  or  other 
conditions  make  the  use  of  so  efficient  a  process  unnecessary. 

Settling  basins,  like  screens,  are  commonly  referred  to  as  preliminary  processes 
of  sewage  treatment  in  reference  to  their  ability  to  prepare  sewage  for  application  to 
percolating  filters,  contact  beds  and  other  finishing  processes.  Unless  followed  by 
some  oxidizing  process,  such  as  is  afforded  by  sprinkling  filters  or  contact  beds, 
settling  basins  leave  the  largest  part  of  the  work  of  purification  to  fall  upon  the  nat- 
ural body  of  water  into  which  the  effluent  is  discharged. 

Of  the  removal  of  60  per  cent,  of  the  suspended  solid  matter  in  the  sewage  con- 
taining 30  per  cent,  of  the  total  organic  matter  about  two-thirds  is  probably  capable 
of  making  an  appreciable  demand  upon  the  dissolved  oxygen,  leaving  80  per  cent,  of 
the  organic  matter  originally  present  in  the  sewage  to  be  discharged  in  the  effluent. 
Settling  basins  providing  for  a  two  hours'  sedimentation  period  for  the  sewage  of 
New  York  could  alone  not  be  expected  to  reduce  the  demand  which  the  sewage  would 
make  upon  the  dissolved  oxygen  in  the  harbor  by  more  than  about  20  per  cent. 

However  insufficient  settling  basins  may  appear  to  be  when  regarded  from  the 
standpoint  of  the  oxygen  demand,  they  represent  the  most  efficient  process  of  sewage 
treatment  which  can  be  installed  on  a  very  large  scale  within  the  limits  of  New  York 
City.  Greater  efficiency  could  only  be  provided  by  sprinkling  filters  or  contact  beds, 
and  either  of  these  would  require  excessively  large  areas  of  land  and  be  certain  to 
cause  offensive  odors  during  warm  weather.  It  is  the  opinion  of  the  Commission  and 
that  of  all  of  its  experts  who  have  given  careful  consideration  to  the  subject  that 
sprinkling  filters  should  not  be  employed  anywhere  within  the  city  limits  unless 
under  exceptional  conditions  and  in  locations  comparatively  remote  from  residences 
and  business  places. 

Disposition  of  Sludge  and  the  Emscher  Tank 

One  of  the  principal  difficulties  connected  with  the  operation  of  settling  tanks 
has  hitherto  been  the  necessity  for  disposing  of  their  sludge.  This  material,  a  liquid 
black  mud,  consists  partly  of  colloidal  material  which  parts  with  its  water  only  with 
difficulty  and  is  susceptible  of  offensive  decomposition  under  warm  weather  condi- 


304  REPORTS  OF  EXPERTS 

tions.  The  disposition  of  the  sludge  has  long  been  regarded  as  the  most  troublesome 
problem  in  the  entire  field  of  sewage  purification.  This  difficulty  is  greatest  in 
crowded  inland  cities ;  it  is  least  in  seaboard  cities  for  these  can  pump  the  sludge  into 
tank  steamers  and  carry  it  to  the  open  ocean  for  disposal.  London,  Glasgow,  Man- 
chester, Salford  and  Dublin  dispose  of  their  sludge  in  this  manner. 

The  Emscher  tank  is  provided  with  a  hopper  bottom  where  the  suspended  solids 
of  the  sewage  may  settle  and  ferment  without  producing  offensive  odors  or  injuriously 
affecting  the  overlying  sewage.  By  fermentation,  the  sludge  becomes  diminished  in 
bulk  and  is  reduced  to  a  state  in  which  it  readily  parts  with  its  water  when  spread 
upon  suitable  drying  beds.  The  tank  is  the  invention  of  Dr.  Karl  Imhoff,  of  Essen, 
Germany,  who  holds  patents  for  it  in  all  the  principal  countries  of  the  world. 

Recently  introduced  in  the  Emscher  drainage  district  of  Germany  as  a  means  of 
removing  a  large  part  of  the  suspended  matters  from  sewage  preparatory  to  discharg- 
ing it  into  a  system  of  long,  open  drains  which  eventually  empty  into  the  Rhine  below 
Cologne,  the  Imhoff  tank  has  rapidly  gained  favor  among  engineers,  and  numerous 
plants  operating  upon  this  principle,  most  of  them  in  connection  with  sprinkling 
filters,  have  been  put  under  construction  within  the  last  four  years. 

The  Commission  has  given  serious  consideration  to  the  use  of  Emscher  tanks  as  a 
means  of  preparing  the  sewage  of  New  York  for  local  discbarge  and  for  discharge 
from  centrally  located  points,  such  as  Ward's  Island  and  the  ocean  island.  Desiring 
to  obtain  an  authoritative  opinion  upon  their  use,  and  believing  that  the  arguments 
which  might  be  put  forward  in  their  favor  by  an  advocate  would  contain  the  most 
favorable  statements  which  could  be  made  in  comparison  with  other  forms  of  sedi- 
mentation, the  Commission,  in  1912,  requested  Dr.  Imhoff  to  make  a  report  upon  his 
invention  as  applicable  to  New  York. 

Karl  Imhoff,  Doctor  of  Engineering,  of  Essen,  Germany,  is  an  engineer  of 
high  standing  both  in  his  native  country  and  abroad.  Formerly  connected  with  the 
Royal  Prussian  Water  and  Sewage  Testing  Station  at  Berlin,  he  has  for  some  years 
been  Engineer  of  Sewage  Disposal  of  the  Emscher  District  Drainage  Board  of 
Germany. 

In  preparation  for  his  report,  Dr.  Imhoff  made  an  inspection  of  the  harbor  on 
September  30,  1912;  an  earlier  inspection  was  made  by  him  on  May  26,  1911.  Vari- 
ous conferences  with  members  of  the  Commission  and  its  staff,  the  examination  of 
the  Commission's  reports  and  some  familiarity  with  American  conditions  gained  on 
four  short  trips  to  America  in  the  years  1909  to  1912  constituted  Dr.  Imhoff's  prep- 
aration for  his  work. 

As  a  basis  for  his  report,  a  series  of  questions  was  placed  by  the  Commission 


REPORT  OF  KARL  IMHOFF  305 

before  Dr.  Imhoff.  He  was  requested  to  express  an  opinion  as  to  whether  Emscher 
tank  treatment  was  sufficient  to  bring  about  the  standard  of  cleanness  for  the  harbor 
which  the  Commission  proposed  in  its  report  of  August,  1912;  how  and  where  Em- 
scher tanks  could  be  installed  in  the  New  York  territory  and,  if  Emscher  tanks  were 
not  sufficient  to  accomplish  the  desired  results,  what  other  process  should  be  com- 
bined with  them. 

Synopsis  of  Dr.  Imhoff's  Report 

Dr.  Imhoff's  report  states  that  the  suggestions  made  as  to  the  practicability  of 
constructing  Emscher  tanks  in  the  built-up  parts  of  New  York  and  the  use  of 
chemicals  are  based  upon  assumptions  and  might  have  to  be  materially  modified  by 
local  conditions.  He  says  the  question  whether  it  would  be  feasible  to  build  such 
works  on  the  shores  of  the  inner  harbor  depends  upon  the  possibility  of  acquiring 
proper  sites  and  upon  the  cost  of  land.  He  disclaims  sufficient  familiarity  with  con- 
ditions in  the  metropolitan  district  to  warrant  him  in  giving  technical  details.  He 
has  therefore  only  given  capacity  figures,  intending  that  they  should  be  used  as  a 
basis  for  calculation  by  the  Commission. 

Dr.  Imhoff  considers  the  most  difficult  provisions  of  the  Commission's  standard 
of  cleanness  to  comply  with  are  those  which  relate  to  deposits  and  to  oxygen.  He 
thinks  it  unavoidable  that  deposits  somewhat  resembling  sewage  sludge  should  occur 
through  the  death  and  decomposition  of  plankton  which  he  says  cannot  thrive  in  the 
mixture  of  ocean  and  upland  water  which  exists.  Owing  to  the  fact  that  sea  water 
has  a  precipitating  action  upon  all  suspended  matter  and  because  of  the  unfavor- 
able conditions  for  the  plankton,  the  harbor  is  not  regarded  by  Dr.  Imhoff  as  afford- 
ing favorable  conditions  for  the  assimilation  of  sewage.  He  agrees  with  Dr.  Adeney 
that  it  is  the  sewage  sludge  which  produces  the  intense  nuisance  which  exists  in  places 
and  not  the  liquid  part  of  the  sewage.  The  average  figures  for  dissolved  oxygen  are 
not,  in  Dr.  Imhoff's  opinion,  capable  of  indicating  the  presence  of  offensive  conditions 
due  to  the  fermenting  sludge. 

As  to  efficiency,  Dr.  Imhoff  does  not  consider  that  Emscher  tanks  are  capable  of 
satisfying  the  Commission's  standard  either  with  respect  to  dissolved  oxygen  or  to 
the  deposit  of  sewage  matters  in  the  vicinity  of  sewer  outfalls,  but  all  the  other  re- 
quirements of  the  standard  can  easily  be  complied  with.  It  is  impossible  for  him  to 
say  how  much  sludge  can  be  held  back  by  tank  treatment;  he  is  inclined  to  consider 
the  probable  amount  about  one-half.  He  thinks  that  which  would  be  retained  would 
be  more  objectionable  than  that  which  escaped  into  the  harbor. 

If  Emscher  tanks  were  not  sufficient,  their  efficiency  might  be  augmented  by  the 
addition  of  chemicals.    The  effect  would  be  to  remove  practically  all  the  suspended 


306  REPORTS  OF  EXPERTS 

matter  and  much  of  the  colloid  matter.  More  sludge  would  be  produced  and  this,  Dr. 
Iiuhoff  says,  would  require  that  the  sludge  chamber  in  the  tanks  be  increased  about 
70  per  cent,  above  the  size  required  for  plain  sedimentation.  The  report  states  that 
Emscher  tanks  are  capable  of  reducing  the  volume  of  sludge,  even  when  chemicals 
are  used. 

Dr.  Imhoff  is  of  the  opinion  that,  if  chemicals  were  used,  that  part  of  the  Com- 
mission's standard  which  refers  to  deposits  could  be  practically  satisfied,  but  it  is 
doubtful  whether  the  reference  to  oxygen  could  be  complied  with. 

In  the  outlying  districts  of  the  city,  Emscher  tanks  could,  in  Dr.  Imhoff's  opinion, 
be  advantageously  combined  with  percolating  filters.  In  the  city  limits,  filters  of  this 
type  would  not  be  admissible  because  of  the  large  areas  required  and  the  nuisance 
from  odors  and  flies  which  would  be  practically  certain  to  arise  from  them.  Chem- 
ical treatment  combined  with  Emscher  tanks  is  recommended  by  Dr.  Imhoff  as  an 
alternative  to  sedimentation  combined  witli  percolating  filters  for  such  situations  as 
are  suitable  for  them.  The  plants  which  he  proposes  would  consist  of  Emscher  tanks 
with  the  application  of  precipitating  chemicals,  aeration  and  rapid  filtration.  This 
process,  Dr.  Imhoff  states,  would  be  cheaper  and  require  less  area  than  percolating 
filters.  In  winter,  when  the  best  treatment  procurable  was  not  needed,  it  would  not 
be  necessary  to  employ  the  chemicals,  thereby  saving  a  considerable  amount  of  money 
over  percolating  filters  which  would  represent  a  considerable  investment. 

In  Dr.  Imhoff's  opinion,  Emscher  tanks  can  be  installed  in  the  built-up  parts  of  the 
city.  For  local  use,  he  says  they  should  be  placed  at  the  mouths  of  the  sewer  outfalls, 
suitably  grouped  by  means  of  intercepting  sewers  so  as  to  produce  a  minimum  total 
cost  for  Emscher  tank  treatment.  The  tanks  could  be  built,  in  his  opinion,  beneath  the 
streets  or  in  other  open  spaces  and  covered  like  the  subways  so  as  not  to  interfere  with 
traffic  overhead.  Sludge  pipes  would  carry  the  sewage  by  pumping  to  steamers  at  the 
water  front  which,  after  receiving  the  sludge,  would  carry  it  to  the  ocean  for  final 
disposal.  Tanks  built  beneath  the  streets  would  not  give  rise  to  nuisance,  the  report 
says,  because  little  odor  would  be  produced  and  the  gases  could  be  taken  care  of  by 
ventilation. 

Assuming  700  million  gallons  per  day  as  the  quantity  of  sewage  to  be  dealt  with 
and  that  one-eighteenth  of  the  daily  flow  would  run  off  in  one  hour,  the  cubic  space 
which  should  be  provided  for  settling  basins  on  the  Imhoff  tank  principle  would  be 
about  10,000,000  cubic  feet  if  it  was  intended  to  provide  for  one  hour's  period  for 
sedimentation  without  chemicals.  The  amount  of  sludge  produced  would  be  about 
1,330  cubic  yards  per  day.  If  chemicals  were  to  be  added  to  facilitate  deposition,  the 
sludge  digesting  chambers  would  have  to  be  larger  than  for  plain  sedimentation.  In- 


REPORT  OF  KARL  IMHOFF  307 

stead  of  allowing  4,200,000  cubic  feet  as  Dr.Imhoff  advises  that  7,000,000  cubic  feet  be 
provided. 

Comments  by  the  Commission  on  De.  Imhoff's  Report 

It  will  be  observed  that  the  sedimentation  period  provided  for  by  Dr.  Imhoff  in 
his  estimates  is  one  hour  instead  of  two,  which  most  authorities  regard  as  the  optimum. 
The  Commission  considers  that  50  per  cent,  is  a  rather  large  removal  of  suspended 
matter  to  expect  for  settling  basins  operating  with  a  one-hour  period.  In  this  con- 
nection, it  must  be  remembered  that  the  supply  of  sewage  is  not  uniform  and  that 
there  are  times  when  the  flow  is  so  much  greater  than  the  average  that  the  settling 
period  in  basins  intended  to  provide  for  one  hour  would  be  much  reduced.  Excep- 
tionally large  amounts  of  suspended  matter  would  be  likely  to  be  brought  down  by 
the  sewage  when  the  flow  was  greatest,  in  consequence  of  which  it  is  possible  that 
considerably  more  deposit-forming  material  would  be  carried  through  the  settling 
basins  into  the  harbor  than  might  be  expected. 

The  Commission  is  in  favor  of  chemical  precipitation  for  those  situations  such  as 
Wards  Island,  where  the  purification  effected  by  plain  sedimentation  may  in  time  not 
prove  sufficient,  and  where  sufficient  protection  to  the  harbor  can  be  effected  by 
settling  the  sewage  more  thoroughly. 

The  assumption  that  the  sewage  deposits  in  the  harbor  do  not  make  a  material 
effect  upon  the  dissolved  oxygen  is  not  in  accordance  with  the  Commission's  opinion 
nor  with  that  of  most  other  investigators  of  the  New  York  problem.  It  is  true  tbat  the 
amount  of  dissolved  oxygen  present  in  any  large  section  of  the  harbor  does  not  afford 
an  infallible  indication  of  the  local  nuisance  which  may  occur  from  fermenting  sludge. 
But  the  evolution  of  gas  carries  particles  of  the  putrefying  sludge  into  the  overlying 
water  and  these  particles  possess  a  strong  avidity  for  oxygen  which  makes  itself  felt 
not  only  where  the  bubbling  occurs  but  elsewhere  by  diffusion. 

The  water  of  New  York  harbor  is  not  unfavorable  to  plankton,  so  far  as  the 
Commission's  knowledge  of  the  facts  extends.  The  average  percentage  of  upland 
water  in  Upper  New  York  bay  and  the  Lower  East  river  is  between  30  and  40 
per  cent.,  or  roughly,  the  inner  harbor  is  two-thirds  as  salt  as  the  open  ocean.  If 
minute  animals  and  plants  which  are  natural  to  the  sea  are  destroyed  by  upland 
water,  and  if  upland  fauna  and  flora  are  killed  when  they  come  into  contact  with  sea 
water,  there  is  no  evidence  to  suppose  that  such  a  fatal  zone  of  change  lies  in  the 
harbor  of  New  York.  The  Commission's  observations  indicate  that  plankton  grow 
abundantly  in  these  waters.  See  the  results  of  microscopic  examinations  of  river 
and  harbor  sediments  showing  living  animal  and  vegetable  forms  in  the  Commis- 


308  REPORTS  OF  EXPERTS 

sion's  report  of  April,  1910,  Part  III,  Chapter  IX,  pp.  419-421;  the  rapid  rate  at 
which  solids  were  digested  through  these  agencies,  in  the  same  report,  Part  III, 
Chapter  X,  p.  461-462;  the  location  and  extent  of  the  shellfish  whose  food  consists 
of  plankton,  in  the  same  report,  Chapter  XI,  Section  II,  pp.  472-476.  The  numerous 
analyses  which  have  been  made  show  that  the  putrefying  deposits  are  largely  due  to 
sewage.  See  the  Commission's  report  of  August,  1912,  Part  III,  Chapter  I,  pp.  171-223. 

After  giving  careful  consideration  to  Dr.  Imhoff's  report  and  making  various 
studies  for  such  works  in  various  locations,  the  Commission  is  compelled  to  state  that, 
in  its  opinion,  the  suggestion  that  Emscher  settling  basins  could  be  located  in  the 
built-up  parts  of  the  city  would  not  be  satisfactory.  They  would  not  be  satisfactory 
because  of  their  cost,  probability  of  nuisance,  and  the  practical  certainty  of  public 
opposition.  The  relatively  small  efficiency  which  could  be  accomplished  by  them  would 
not  be  commensurate  with  the  cost  of  construction  and  maintenance.  These  state- 
ments apply  to  Emscher  tanks  and  all  other  settling  basins  operating  on  the  principle 
of  plain  sedimentation  and  they  have  equal  reference  to  tanks  operated  on  the  prin- 
ciple of  chemical  precipitation. 

Tentative  plans  for  the  construction  of  Emscher  tanks  beneath  the  city  streets 
had  been  prepared  by  the  Commission  before  Dr.  Imhoff's  report  was  made  and  his 
report  states  that  he  examined  these  plans  and  regarded  them  favorably.  Since  these 
plans  represent  what  was  intended  to  be  a  practical  application  of  the  idea  of  system- 
atic treatment  of  New  York's  sewage  by  locally  placed  sedimentation  basins  and  rep- 
resent in  many  respects  the  provisions  which  might  be  made  for  treating  the  sewage 
by  sedimentation  in  Dortmund  tanks  for  local  discharge,  they  will  be  described  here  at 
some  length. 

The  plans  provided  for  a  plant  of  8  Emscher  tanks  having  a  capacity  of  12,000,000 
gallons  per  24  hours,  with  a  settling  period  of  one  hour.  They  would  be  located  be- 
neath a  marginal  street  bordering  the  Hudson  river  or  Lower  East  river.  The  prin- 
ciple was  sedimentation  without  the  use  of  chemicals. 

The  tanks  were  circular  in  plan,  35  feet  outside  diameter  and  arranged  closely  to- 
gether in  a  single  row  which  took  up  a  large  part  of  the  space  available  between  the 
sidewalk  curbing  on  the  one  side  and  the  bulkhead  of  the  marginal  street  on  the  other. 
A  pumping  plant  operated  by  direct-connected  electric  motors  carried  the  sewage  away 
from  the  works  for  discharge  by  means  of  submerged  outlets  or  otherwise.  The  settling 
basins  were  protected  by  means  of  a  coarse  screen,  simple  grit  chamber  and  automatic 
gate  to  prevent  flooding.  Blowers  and  air  ducts  were  to  be  used  in  order  to  carry 
away  the  gases  and  water-saturated  air  from  above  the  tanks ;  inlets  were  arranged  for 
the  supply  of  fresh  air. 


REPORT  OF  KARL  IMHOFF  309 

The  tanks  were  to  be  35  feet  deep  from  the  surface  of  the  sewage  to  the  extreme 
bottom.  There  was  to  be  a  space  of  12  feet  between  the  sewage  and  the  top  of  the 
street  paving  overhead,  the  total  depth  of  construction  beneath  the  street  pavement 
thus  amounting  to  47  feet.    The  total  length  of  the  plant  was  343  feet. 

The  sewage  would  be  supplied  through  interceptors  which  would  run  along  the 
water  front  to  collect  the  sewage  from  the  common  sewers  which  otherwise  would 
discharge  into  the  harbor.  Provision  would  be  made  for  sending  storm  water  in  ex- 
cess of  the  capacity  of  the  plant  direct  to  the  harbor  and  tide  gates  would  be  provided 
to  keep  the  harbor  waters  from  backing  up  past  this  overflow.  The  sewage  would 
enter  at  one  end  of  the  plant,  pass  through  the  coarse  screen  and  grit  chamber  and 
thence  to  the  tanks  by  means  of  a  channel  running  along  one  side  of  the  row  of  8 
tanks.  After  passing  through  the  settling  tanks,  the  effluent  would  be  collected  in  a 
channel  lying  alongside  of  the  tanks  parallel  to  the  channel  supplying  the  raw  sew- 
age and  would  flow  to  the  pumps.  The  sludge  would  be  retained  until  it  was  thor- 
oughly decomposed  by  fermentative  action.  It  would  then  be  removed  by  the  hydro- 
static pressure  of  the  overlying  sewage  to  a  sump  well,  whence  it  would  be  forced  to 
a  tank  ship  lying  at  a  neighboring  pier.  The  screenings  would  be  removed  in  the 
same  vessel. 

As  the  construction  of  the  tanks  would  be  close  to  the  water  front  and  largely  in 
made  ground,  permitting  percolation  under  a  considerable  head  to  the  lower  portion 
of  the  work,  the  method  of  construction  to  be  adopted  is  a  matter  of  importance.  Two 
possible  methods  are  suggested: 

By  one  plan  the  cylindrical  concrete  curbing  or  shell  would  be  provided  with  a 
cutting  edge  at  the  base  and  constructed  in  the  upper  few  feet  of  the  pit  and  above 
ground.  This  would  be  sunk  by  excavation  inside,  the  shell  sinking  by  its  own  weight 
or,  if  necessary,  by  an  added  load  on  top.  Being,  by  its  density,  practically  im- 
pervious, percolation  would  be  cut  off  except  from  under  the  bottom.  If  this  percola- 
tion should  increase  on  sinking  to  such  extent  as  to  be  unmanageable,  it  would  then 
be  reduced  by  allowing  the  pit  to  partially  fill  with  water  and  the  remainder  of  the 
excavation  would  be  done  by  a  clamshell  dredge  assisted,  when  necessary,  by  a  diver. 

On  reaching  a  point  sufficiently  below  the  proposed  base  of  the  tank,  bags  of  con- 
crete would  be  placed  over  the  bottom,  serving  both  to  hold  the  material  down  and  to 
check  percolation.  If  this  were  not  entirely  effective,  grout  could  be  pumped  through 
holes  to  the  underlying  material.  The  pit  would  then  be  pumped  out  and  the  finished 
bottom  laid. 

By  the  other  plan  the  work  would  be  started  as  before,  but  provision  would  be 
made  for  the  insertion  of  a  strong,  watertight,  timber  bulkhead  with  air-lock  before 


310  REPORTS  OP  EXPERTS 

reaching  a  point  where  the  removal  of  water  became  difficult.  From  this  point  on  the 
work  would  continue  under  compressed  air,  as  customary  in  caisson  work. 

In  the  completed  tank,  35  feet  in  diameter  and  extending  to  a  depth  of  over  40 
feet  below  extreme  high  tides,  there  would  be  an  upward  thrust  on  the  base  of  some 
1,350  tons.  To  prevent  floatation,  this  would  be  overcome  by  the  weight  of  the  struc- 
ture and  the  skin  friction  on  the  sides.  The  weight  of  the  concrete  work  as  designed 
would  be  about  1,000  tons  and  that  of  the  steel,  earth  and  paving  in  the  roof  and 
street  surface  about  200  tons,  leaving  150  tons  to  be  overcome  by  skin  friction  or 
about  70  pounds  per  square  foot  of  exposed  surface.  If  the  margin  of  safety  should 
not  be  considered  sufficient  for  this  (1)  the  thickness  of  the  curbing  could  be  increased 
sufficiently  to  give  the  added  weight  required  (from  18  inches  to  not  over  24  inches) 
or,  (2)  the  empty  tank  could  be  so  connected  to  the  adjacent  tanks  filled  with  sewage  as 
to  be  held  in  position  by  the  latter.  This  could  be  effected  by  constructing  the  series  of 
tanks  in  contact  with  each  other. 

In  order  to  provide  head  room  for  operation  the  roof  covering  the  tank  chamber 
is  placed  close  to  the  street  surface  and  is  as  shallow  as  practicable.  In  the  estimates 
this  is  composed  of  24-inch  I-beams  spaced  27  inches  center  to  center,  with  bent  plates 
between  to  support  the  street  surface  without  jack  arches,  which  would  add  consider- 
able weight  to  the  load.  Further  study  would  probably  indicate  some  more  econom- 
ical design  that  would  be  equally  serviceable  for  this,  such  as  the  use  of  deeper  built 
girders  with  buckled  plates  between,  but  the  estimate  is  believed  to  be  safe. 

The  estimated  cost  of  construction  is: 

For  Emscher  Tank  Plant  $220,000 

For  Outlet  in  Deep  Water   14,200 

Total  7.  $234,200 

The  estimated  annual  charges  are: 

For  Operation   $13,250 

For  Fixed  Charges   12,850 

Total  ~  $26,100 

The  total  volume  of  sewage  to  be  expected  from  the  Lower  East  river,  Hudson 
and  Bay  Division,  not  far  from  1960,  and  the  number  of  12  mgd.  plants  required  may 
be  determined  as  follows: 

Volume  of  Number  of  Emscher 

Sewage  mgd.  *  Tank  Plants 

Manhattan:  Hudson  river   255  22 

East  river   193  16 

448  38 

Queens:       East  river   75  6 

Brooklyn:     East  river   240  20 

Buttermilk  channel   18  2 

Upper  bay   105  9 

363  31 

Total   886  75 

'Million  Gallons  per  24  hours. 


REPORT  OF  KARL  IMHOFF  311 

It  is  possible  that  in  some  places  an  Emscher  tank  plant  could  be  constructed 
without  pumps,  thereby  effecting  a  considerable  saving,  both  in  first  cost  and  in 
maintenance  charges.  Where,  however,  the  effect  of  the  tide  would  be  felt  in  sewers 
at  the  site  of  the  plant,  it  would  be  necessary  either  to  exclude  the  harbor  water  by 
tide  gates  and  pump  the  sewage,  or  so  construct  the  works  as  to  act  without  reference 
to  the  tidal  levels. 

Since  a  large  part  of  the  water  front  of  Manhattan  is  at  so  low  an  elevation 
that  the  sewers  lying  but  a  few  feet  beneath  the  surface  are  tide-locked  for  500  feet 
or  more  inland,  there  is  poor  opportunity  for  building  Emscher  tanks  without  ex- 
cluding the  tide  water.  Provision  of  head  room,  amounting  preferably  to  about  12 
feet  above  the  sewage,  would  be  impossible  in  most  cases  if  the  tanks  were  to  be 
located  upon  the  marginal  streets.  It  is  not  clear  whether  Emscher  tanks,  unpro- 
tected from  tidal  influence,  would  operate  satisfactorily  even  if  the  structural  diffi- 
culties, due  to  want  of  head  room,  height  of  ground  water  and  crowded  space,  could 
be  overcome.  The  average  period  of  sedimentation  would  be  short  and  irregular, 
due  to  the  alternate  backing  up  and  outflow  of  the  sewage  under  the  action  of  the 
tidal  head. 

The  tanks  might  be  built  at  a  sufficient  distance  back  from  the  water  front  to  be 
free  from  interference  by  the  tides,  but  this  would  require  the  reconstruction  of  the 
common  sewerage  system  throughout  that  part  of  the  city  which  lay  between  the 
tanks  and  the  water  front.  Another  difficulty  to  be  overcome,  and  a  more  serious 
one,  would  be  found  in  the  fact  that  the  streets  beneath  the  surface  are  already  occu- 
pied with  water  and  steam  pipes  and  conduits  for  electric  light,  telegraph,  telephone 
and  power  purposes.  The  Emscher  tanks  would  have  to  be  arranged  in  single  file 
and,  for  a  plant  of  moderate  size,  the  length  of  street  appropriated  would  be  more 
than  one  block  long.  A  plant  to  deal  with  20,000,000  gallons  would  be  about  570  feet 
long  if  the  period  for  sedimentation  was  to  be  one  hour  and  about  1,100  feet  long,  or 
more  than  one-fifth  of  a  mile,  if  the  sedimentation  period  provided  was  two  hours.  To 
deal  with  all  the  sewage  which  will  be  produced  by  Manhattan  Island  in  1940,  an 
aggregate  of  about  2>y^  miles  of  tanks  would  be  required,  if  the  sedimentation  period 
was  one  hour,  and  about  7  miles,  if  this  period  was  two  hours. 

Serious  question  might  be  raised,  in  the  Commission's  opinion,  as  to  the  proba- 
bility of  trouble  from  the  gas  given  off  in  the  fermentation  of  sludge  in  Emscher 
tanks  when  placed  in  crowded  positions  beneath  the  city's  streets.  The  odors  might 
not  be  offensive,  although  this  is  not  certain,  but  large  volumes  of  inflammable  gas 


312  REPORTS  OF  EXPERTS 

would  be  produced  and  this,  when  mixed  with  air  in  the  confined  space  beneath  the 
street  pavements,  might  lead  to  explosions. 

Private  property  might  be  acquired,  either  by  purchase  or  by  condemnation,  to 
serve  as  sites  for  Emscher  tank  installations,  and,  if  this  were  done,  some  of  the 
difficulties,  especially  those  which  relate  to  crowding,  want  of  ventilation  and  incon- 
veniently long  collections  of  tanks,  could,  in  large  measure,  be  overcome.  Settling 
basins  so  located  would  not  reduce  the  chance  of  nuisance  nor  the  public  protest 
which  might  reasonably  be  expected  against  them,  nor  would  they  add  to  the 
ability  of  the  works  to  purify  the  sewage,  and  the  cost  of  the  land  would  add  to  the 
expense. 

There  is  no  precedent,  so  far  as  the  Commission  is  aware,  for  such  extensive 
underground  sewage  treatment  works  as  are  here  discussed.  No  city  seems  to  have 
placed  settling  tanks  of  large  capacity,  operating  with  or  without  sludge  fermenting 
chambers,  beneath  the  street  pavements.  No  plant  of  Emscher  settling  tanks  has  thus 
far  been  constructed  to  operate  with  such  tidal  interference  as  would  be  met  with 
(unless  avoided  by  tide  gates  and  pumping)  in  the  most  congested  sections  of  the 
city. 

As  to  the  removal  of  the  sludge,  Emscher  tanks  undoubtedly  afford  one  of  the 
best  means  of  overcoming  the  difficulties  of  cost  of  sludge  disposal  in  inland  cities. 
But  New  York  is  particularly  favored  in  being  close  to  the  sea  and  so  able  to  ship  its 
sludge  to  the  open  ocean  at  less  cost  than  any  other  method  of  disposal.  Whether 
it  would  be  feasible  to  transport  fermented  sludge,  charged  as  it  is  with  gas,  un- 
less special  provision  for  the  escape  of  the  gas  was  made  on  the  ships,  appears 
doubtful. 

The  comparative  value  of  Emscher  tanks  and  other  deep  tanks  in  which  sludge 
is  not  digested  lies  in  the  opportunities  which  are  afforded  by  Emscher  tanks  for  the 
fermentation  of  the  sludge  and  the  consequent  reduction  in  its  volume.  This  advan- 
tage is  gained  at  the  cost  of  providing  a  large  storage  place  for  the  sludge  at  the 
bottom  of  the  compartment  in  which  the  suspended  matter  deposits  and  ferments.  In 
New  York  the  construction  of  the  deep  sludge  chamber  would  be  very  costly.  So  far 
as  the  Commission  has  been  able  to  cover  the  point  in  its  studies  and  estimates,  it 
would  appear  that  the  peculiar  advantages  which  the  Emscher  type  of  tank  affords 
over  the  Dortmund  are  not  warranted  by  the  greater  cost  of  the  Emscher  tanks. 


REPORT  OF  KARL  IMHOFF 


313 


REPORT  OF  KARL  IMHOFF 

To  the  President  and  Members  of  the  Metropolitan  Sewerage  Commission  of  New 
York. 

Gentlemen  :  The  following  questions  have  been  put  to  me  by  Mr.  Soper,  President 
of  the  Metropolitan  Sewerage  Commission : 

(1)  Is  Emscher  Tank  Treatment  sufficient  to  bring  about  the  standard  of  purity 
required  by  the  Commission?    (Report  August  1,  1912,  p.  70.) 

(2)  How  and  where  may  Emscher  Tanks  be  installed? 

(3)  If  Emscher  Tanks  are  not  sufficient,  with  what  other  process  should  they 
be  combined? 

Sources  of  Information: 

"Report  of  Metropolitan  Sewerage  Commission,  April  30th,  1910." 

"Report  of  Metropolitan  Sewerage  Commission,  August  1st,  1912." 

Preliminary  Reports  of  the  Metropolitan  Sewerage  Commission  Nos.  I,  II,  III, 
and  IV,  dated  September,  1911,  November,  1911,  November,  1911,  and  July,  1912. 

Four  short  trips  to  America  in  the  years  1909-1912. 

Inspection  of  New  York  Harbor  May  26th,  1911,  in  company  with  Mr.  Soper  and 
his  first  assistant,  Mr.  John  H.  Gregory. 

A  conference,  September  30th,  1912,  with  Mr.  Soper  regarding  the  results  of  in- 
vestigations made  in  the  preceding  year. 

Question  Number  One 

Is  Emscher  Tank  Treatment  sufficient  to  bring  about  the  standard  of  purity  re- 
quired by  the  Commission? 

These  standards  are  as  follows: 

(1)  Garbage,  offal  or  solid  matter  recognizable  as  of  sewage  origin  shall  not  be 
visible  in  any  of  the  harbor  waters. 

(2)  Marked  discoloration  or  turbidity,  due  to  sewage  or  trade  wastes,  efferves- 
cense,  oily  sleek,  odor  or  deposits  shall  not  occur  except  perhaps  in  the  immediate 
vicinity  of  sewer  outfalls,  and  then  only  to  such  an  extent  and  in  such  places  as  may 
be  permitted  by  the  authority  having  jurisdiction  over  the  sanitary  condition  of  the 
harbor. 

(3)  The  discharge  of  sewage  shall  not  materially  contribute  to  the  formation  of 
deposits  injurious  to  navigation. 

(4)  Except  in  the  immediate  vicinity  of  docks  and  piers  and  sewer  outfalls,  the 
dissolved  oxygen  in  the  water  shall  not  fall  below  3.0  cubic  centimeters  per  liter  of 
water.  Near  docks  and  piers  there  should  always  be  sufficient  oxygen  in  the  water 
to  prevent  nuisance  from  odors. 

(5)  The  quality  of  the  water  at  points  suitable  for  bathing  and  oyster  culture 
should  conform  substantially  as  to  bacterial  purity  to  a  drinking  water  standard. 
It  is  not  practicable  to  maintain  so  high  a  standard  in  any  part  of  the  harbor  north 
of  the  Narrows,  or  in  the  Arthur  Kill.  In  the  Lower  Bay  and  elsewhere  bathing  and 
the  taking  of  shellfish  cannot  be  considered  free  froin  danger  within  a  mile  of  a  sewer 
outfall. 


314 


REPORTS  OF  EXPERTS 


Of  these  five  standards  Nos.  2  and  4  are,  so  far  as  this  report  is  concerned,  the 
most  vital.    They  will  therefore  be  considered  first. 

Standard  No.  2  says  plainly:  "Deposits  shall  not  occur  except  perhaps  in  the 
immediate  vicinity  of  sewer  outfalls."  This  is  a  requirement  very  difficult  to  satisfy. 
Sludge  deposits  occur  in  tidal  harbors  at  the  mouths  of  rivers  even  when  there  is  no 
discharge  of  sewage  into  the  harbor.  The  fine  mineral  matters  held  in  suspension  in 
every  river  water,  such  as,  for  example,  the  fine  clay  particles,  settle  out  rapidly  as 
soon  as  they  reach  the  brackish  water  zone,  and  for  this  reason  deposits  of  sludge  are 
always  found  in  harbors  situated  at  the  junction  of  land  rivers  and  large  salt  water 
bodies.  These  sludge  deposits,  however,  are  different  in  appearance  from  ordinary 
sewage  sludge  deposits. 

Further,  the  plankton  (a  term  designating,  collectively,  the  minute  animal  and 
plant  life  in  a  water)  of  the  river  water  forms  deposits  at  the  junction  of  a  river 
with  salt  water  bodies.  As  long  as  this  plankton  is  alive  it  neither  settles  nor  floats, 
but  remains  in  suspension  due  to  its  life  energy.  As  soon,  however,  as  the  fresh 
water  is  mixed  with  salt  water,  or  sea  water,  the  plankton  of  the  fresh  water  finds 
itself  in  an  unfavorable  environment,  dies,  settles  out  and  remains  as  sludge. 
Again,  sea  water  also  contains  plankton,  but  plankton  of  an  altogether  differ- 
ent kind.  It  also  dies  when  fresh  water  is  mixed  with  its  sea  water  environment. 
Therefore,  in  the  brackish  zone  (i.  e.,  that  area  in  which  is  found  a  mixture  of  sea 
and  land  waters)  there  is  a  continual  process  of  dying  off  and  settling  out  of  plank- 
ton of  both  kinds. 

The  natural  river  sludge  and  this  dead  plankton  sludge,  however,  do  not  settle 
out  in  a  layer  of  uniform  thickness  on  the  bottom  of  the  brackish  zone.  The  tides  in 
this  brackish  zone  are  the  cause  of  continually  reversing  currents,  and  these  currents 
shift  the  light  sludge  about  until  it  finally  finds  itself  in  positions  where  the  velocity 
of  currents  is  sufficiently  low  to  permit  of  its  remaining  there.  Such  positions  will, 
of  course,  be  near  shores,  on  flats  which  are  alternately  covered  and  uncovered  with 
water,  and  in  the  wharves  and  docks.  In  such  places  as  these  the  sludge  can  ac- 
cumulate in  large  quantities,  and  in  these  sludge  accumulations  decomposition  will 
take  place.  Sludge  of  plankton  origin  taken  from  such  places  is  generally  black  and 
contains  gases  of  decomposition.  Hence  it  is  often  difficult  to  distinguish  between  it 
and  half  decomposed  sewage  sludge. 

In  any  brackish  zone,  therefore,  sludge  deposits  occur  other  than  those  due  to 
sewage,  and  are  often  in  appearance  similar  to  sewage  sludge.  In  Standard  No.  2 
presumably  only  such  deposits  are  referred  to  as  arise  from  sewage  sludge. 

The  pollution  in  sewage  consists  of : 

(1)  The  suspended  matters  (such  as  fecal  matters,  street  washings  and  kitchen 
refuse) . 

(2)  Dissolved  matters  (such  as  urine,  trade  liquors,  etc.). 

(3)  Colloidal  matters,  which  are  in  character  between  dissolved  and  suspended 
matters. 

Of  these  polluting  matters  the  greatest  part  of  the  suspended  matters  forms 
sludge  when  the  sewage  is  caused  to  flow  slowly  through  a  tank.  If  the  sewage  is 
permitted  to  flow  into  a  harbor  without  tank  treatment,  as  is  now  the  case  in  New 
York  City,  it  is  certain  that  at  least  that  portion  which  settles  out  in  tanks  will  settle 
out  in  the  harbor.  But  when  sea  water  is  present  sludge  forms  to  a  larger  extent 
than  this.    Not  only  the  larger  part,  but  practically  all  of  the  suspended  matters 

I 


REPORT  OF  KARL  IMHOFF 


315 


settle  out,  principally  due  to  the  influence  of  the  salt  water.  Even  a  large  part  of 
the  colloidal  matters  may  be  thrown  out  from  this  cause.  Of  the  dissolved  matters 
it  is  probable  that  only  a  very  small  portion  will  form  sludge,  as  the  formation  of 
sludge  from  dissolved  matters  is  mainly  a  result  of  that  which  is  generally  termed 
self-purification ;  and  there  is  only  a  low  degree  of  self-purification  in  brackish 
waters.  This  is  because  self-purification,  so  far  as  the  dissolved  organic  matters  are 
concerned,  is  mainly  brought  about  by  the  action  of  plankton,  and,  as  has  been  out- 
lined above,  brackish  water  contains  only  a  very  small  amount  of  living  plankton. 

In  general,  then,  it  is  only  the  dissolved  matters  which  are  carried  out  to  sea 
before  they  have  a  chance  to  form  sludge.  Through  tank  treatment  alone,  therefore, 
it  is  not  possible  to  prevent  all  deposits  of  sludge.  It  is  difficult  to  say  how  much  of 
the  sludge  formed  under  the  New  York  conditions  may  be  held  back  by  tank  treat- 
ment. I  assume,  for  purposes  of  estimation,  that  the  quantity  may  be  reduced  by 
half.  But  it  should  be  kept  in  mind  that  the  sludge  which  is  held  back  by  tanks  is 
that  portion  which  is  most  objectionable,  and  most  likely  to  produce  nuisance.  In 
fact,  it  is  problematical  whether  the  remaining  portion  is  at  all  capable  of  produc- 
ing a  nuisance  under  the  conditions  obtaining  in  New  York  Harbor. 

From  the  foregoing  it  is  evident  that  the  above-mentioned  part  of  Standard  No. 
2  cannot  literally  be  satisfied  by  tank  treatment  alone. 

Standard  No.  Jf  may  be  here  repeated: 

"Except  in  the  immediate  vicinity  of  docks  and  piers  and  sewer  outfalls,  the  dis- 
solved oxygen  in  the  water  shall  not  fall  below  3.0  cubic  centimeters  per  liter  of 
water.  Near  docks  and  piers  there  should  always  be  sufficient  oxygen  in  the  water 
to  prevent  nuisance  from  odors." 

That  is,  with  60  per  cent,  of  sea  water  and  40  per  cent,  of  land  water,  and  an  ex- 
treme summer  temperature  of  80°  F.,  there  shall  always,  except  near  docks  and  piers 
and  sewer  outfalls,  be  58  per  cent,  or  more  of  oxygen  saturation. 

Referring  to  Plate  "G"  of  the  August  1,  1912,  Metropolitan  Sewerage  Commis- 
sion Report,  which  shows  the  average  dissolved  oxygen  content  of  samples  taken 
between  June  27  and  July  28,  1911,  the  following  values  are  significant: 


Middle  of  Hudson  River,  opposite  W.  42nd  Street  58% 

Mouth  of  Hudson  River,  opposite  the  Battery,  Vi  mile  from  shore  54% 

Middle  of  East  River,  opposite  Lawrence  Point  56% 

Middle  of  Upper  East  River,  opposite  College  Point  55% 

Middle  of  East  River,  near  Brooklyn  Bridge   54% 

Upper  Bay,  1.25  miles  out  from  40th  St.,  Brooklyn  59% 

Mouth  of  Harlem  River,  opposite  Willis  Avenue  Bridge  28% 

Middle  of  Harlem  River,  opposite  Madison  Avenue  Bridge  35% 


None  of  these  samples  were  taken  in  the  immediate  vicinity  of  sewer  outfalls, 
docks  or  piers,  and  it  is  evident,  therefore,  that  the  58  per  cent,  limit  is  reached,  and 
in  many  cases  exceeded,  at  the  present  time.  The  population  of  New  York  City  for  1910 
is  estimated  at  about  4,600,000 ;  for  1940—8,660,000,  nearly  double.  If  Emscher  tanks 
are  sufficient,  therefore,  the  work  they  must  do  is  not  only  to  keep  the  oxygen  figure  up 
to  58  per  cent,  now;  they  must  do  more — they  must  raise  the  oxygen  percentage  to 
such  a  point  above  58  per  cent,  that  the  increased  pollution  passing  the  tanks,  due  to 
the  increase  in  population,  will  not  by  1940  depress  it  lower  than  58  per  cent. 

I  am  thoroughly  in  accord  with  the  opinion  expressed  by  Dr.  Adeney  that  it  is 


316 


REPORTS  OF  EXPERTS 


the  sludge  in  New  York  Harbor  which  causes  the  nuisance,  the  evident  nuisance,  and 
not  the  liquid  sewage.  There  is  no  doubt  that  local  deposits  of  sludge  putrefy  and 
form  gases;  and  that  these  putrefying  sludge  masses  are  at  times  impelled  towards 
the  surface  by  their  gaseous  content,  mingling  intimately  with  the  waters  and  pro- 
ducing various  forms  of  nuisance.  At  these  points  the  oxygen  content  of  the  water 
decreases  very  rapidly,  due  to  the  stage  of  decomposition  of  the  disseminated  sludge 
particles. 

If  it  is  desired  to  base  an  opinion  regarding  the  intensity  of  pollution  of  the 
harbor  upon  such  occurrences  as  these  then  the  oxygen  content  of  the  water  is  an 
approximate  index.  It  should  be  kept  in  mind,  however,  that  this  is  at  best  merely  a 
local  index,  and  that  in  general  the  average  oxygen  content  of  so  large  a  harbor  as 
that  of  New  York  is  more  dependent  upon  the  liquid  sewage  content  than  upon  the 
sludge  deposits.  Since,  however,  as  has  been  pointed  out  above,  the  dissolved  or- 
ganic matters  do  not  cause  the  evident  nuisance,  average  figures  of  oxygen  content 
are  not  an  index  of  such  nuisance  under  the  conditions  prevailing  in  New  York 
Harbor. 

However,  the  question  as  to  the  value  of  the  oxygen  content  as  a  pollution  index 
is  not  within  my  province  to  discuss  further.  I  am  simply  asked  whether  tank  treat- 
ment will  keep  the  oxygen  content  generally  in  the  harbor  as  high  as  3  c.c.'s  per  liter. 

Therefore  I  am  forced  to  reply  literally  that  since  tank  treatment  can  only  at 
best  reduce  the  sludge  deposits,  and  since  it  is  not  these  sludge  deposits  which  prin- 
cipally affect  the  average  oxygen  content,  it  is  not  certain  that  even  at  the  present 
time  tank  treatment  will  satisfy  Standard  No.  4 ;  and  it  is  much  less  certain  in  1940. 

Thus  far  I  have  considered  only  the  two  difficult  requirements. 

Standards  No.  1  and  3,  and  that  part  of  Standard  No.  2  not  concerning  itself  with 
"deposits"  can  be  satisfied  by  tank  treatment  alone. 

Standard  No.  5  does  not  concern  itself  with  the  state  of  pollution  of  the  harbor. 
It  merely,  in  effect,  indicates  the  distances  to  which  bathing  places  and  shellfish  areas 
shall  be  removed  from  sewer  outlets. 

To  sum  up,  the  first  question  may  be  answered  as  folloios:  Tank  treatment  is  suffi- 
cient to  bring  about  the  standard  of  purity  required  by  the  Metropolitan  Sewerage 
Commission  with  the  exception  of  that  clause  of  Standard  No.  2  referring  to  deposits, 
and  of  Standard  No.  4,  referring  to  the  oxygen  content.  These  two  requirements, 
namely,  that  except  in  the  immediate  vicinity  of  sewer  outfalls  no  deposits  shall  occur, 
and  the  oxygen  content  shall  not  fall  below  3  c.c.'s  per  liter,  cannot  be  satisfied  by 
tank  treatment  alone,  especially  not  in  1940. 

Question  Number  Two 
How  and  where  may  Emscher  Tanks  be  installed? 

Emscher  tanks  may  be  installed  either  within  New  York  City  itself  or,  if  a  trunk 
sewer  system  is  built,  outside  of  the  city.  The  idea  of  treating  the  sewage  within  the 
city  itself  is  already  being  considered  by  the  Bureau  of  Sewers  of  the  Borough  of 
Manhattan,  and  this  Bureau  is  now,  so  far  as  I  know,  experimenting  in  one  of  the  tall 
office  buildings  of  Manhattan  with  Emscher  tank  treatment  in  the  cellar  of  the  build- 
ing itself. 

Instead  of  placing  Emscher  tanks  at  the  very  sources  of  pollution,  however,  it  is 


REPORT  OF  KARL  IMHOFF 


317 


also  possible,  and  in  many  respects  simpler,  to  place  them  at  the  mouths  of  the  sewer 
outfalls.  There  are  now,  for  example,  172  outfalls  in  the  Borough  of  Manhattan. 
These  would,  of  course  be  grouped  by  local  interceptors  in  such  a  manner  as  to  pro- 
duce a  minimum  total  cost  of  tank  treatment. 

The  following  figures  will  give  a  conception  of  the  total  size  of  plant  required. 
They  are  computed  on  the  basis  of  the  probable  population  in  1917 : 


Population  of  New  York  City  in  1917  (p.  136,  1910  Report)   5,400,000 

Population  Metropolitan  District  in  N.  Y.  State,  but  outside 

N.  Y.  City,  estimated  from  p.  143,  1910  Report   200,000 

Total  for  Met.  Dist.  N.  Y.  State  in  1917    5,600,000 

Sewage  Produced  in  1917  by  Metropolitan  Dist.  of  N.  Y.  State 
in  gals,  per  day,  computed  on  a  basis  of  125  gals,  per  head 

per  day,  5,600,000X125=  700,000,000  gal.  per  day. 

Settling  Basin  Capacity  Required  for  New  York  City  with  a  sug- 
gested settling  period  of  one  hour :  Assuming  T'T  of  the  daily 


flow  as  running  off  in  one  hour,  we  have  a  necessary  settling 
basin  capacity  of  700,000,000-^18  =  38,900,000  U.  S.  Gals., 

or  in  cubic  feet  38,900,000  -4-7.48  =   5,200,000  cubic  feet. 

Sludge  Room  Capacity  Required,  estimated  at  0.75  cubic  feet  per 

head  =  0.75X5,600,000=   4,200,000  cubic  feet. 

From  an  engineering  standpoint  it  is  without  doubt  possible  to  construct  Em- 
scher  tanks  at  the  mouths  of  the  sewer  outfalls.  The  tanks  would  either  be  built  under 
the  streets  or  under  any  open  area,  and  covered  so  that  traffic  would  not  be  interfered 
with,  just  as  in  the  case  of  the  subways.  From  these  tanks  sludge  pipes  would  lead 
to  such  places  as  would  make  the  collection  of  sludge  by  sludge  steamers  most  easy 
and  economical.  These  sludge  steamers  would  collect  the  sludge  from  the  various 
plants  at  proper  intervals  and  transport  it  either  to  sea  or  to  any  convenient  place 
outside  of  the  city,  where  the  sludge  could  be  dried  and  used  either  for  land  filling 
purposes  or  disposed  of  to  farmers.  The  amount  of  sludge  that  will  have  to  be  trans- 
ported in  this  manner,  estimated  at  0.17  liters  per  head  per  day,  would  be 

0.17  X5,600,000  =  950,000  liters  per  day. 
or    950,000 -T-     28.32  =  33,600  cubic  feet  per  day. 
or     33,600 -r     27      =    1,330  cubic  yards  per  day. 

I  am  not  able  to  give  the  technical  detals  of  such  tanks  because  I  am  not  sufficiently 
well  acquainted  with  conditions  in  the  Metropolitan  District.  The  Commission  has 
made  a  design  for  such  a  unit  plant.  My  impression  is,  from  such  examination  as  I 
was  able  to  make  of  this  design,  that  it  is  constructionally  feasible.  I  am  also  con- 
vinced that  such  a  plant  would  not  give  rise  to  nuisance,  for  but  little  odor  would  be 
produced  and  the  gases  could  be  taken  care  of  by  proper  ventilation.  Further,  the 
pumping  of  sludge  into  steamers  would  not  be  accompanied  by  nuisance. 

The  whole  question  as  to  whether  it  is  possible  to  build  such  tanks  in  the  city 
itself  depends  only  upon  the  possibility  of  acquiring  suitable  locations  and  upon  the 
matter  of  costs.  I  am  not  able,  because  of  my  non-acquaintance  with  local  conditions, 
to  estimate  how  much  such  plants  would  cost  in  New  York  City.  Instead  I  have  given 
above  capacity  figures  from  which  local  engineers  will  be  able  to  estimate  the  costs. 
The  total  inside  volume  of  the  tanks  will  be  about  10,000,000  cubic  feet. 

Emscher  tanks  may,  of  course,  also  be  used  if  New  York  City  decides  to  build  a 
large  trunk  sewer  system  and  transport  the  sewage  outside  of  the  city.  The  Com- 
mission has  already  considered  the  question  of  using  Emscher  tanks  in  such  a  case 


318 


REPORTS  OF  EXPERTS 


and  the  following  estimate  of  costs  is  extracted  from  Appendix  "D"  of  Preliminary- 
Report  No.  1 : 


Land   $4,700,000 

Sewers  to  Barren  Island   51,000,000 

Pumping  Stations   12,140,000 

Treatment  Works  (Emscher  Tanks  and  Percolating  Filters)   49,900,000 

Outfall  Works   5,000,000 


$122,740,000 

Engineering  and  Contingencies,  15%   18,400,000 


$141,150,000 

It  is  not  necessary  to  consider  further  the  details  of  construction  in  this  case,  as 
these  have  already  been  worked  out  under  similar  conditions  in  other  American  cities. 

Question  Number  Three 

"If  Emscher  tanks  are  not  sufficient,  with  what  other  process  should  they  be 
combined?" 

In  case  Emscher  tanks  are  not  sufficient  they  may  be  combined  with  percolating 
filters,  as  indicated  in  the  above  table,  providing  the  scheme  of  carrying  the  sewage 
outside  of  the  city  is  adopted.  If,  however,  the  city  decides  to  treat  its  sewage  within 
the  city  limits  it  will  not  be  possible  to  use  percolating  filters  because  of  the  large  area 
required  and  because  of  the  nuisance  through  odors  and  flies.  Therefore,  if  the  sew- 
age is  treated  within  the  city  it  is  necessary  to  seek  some  other  method. 

I  have  made  clear  in  my  answer  to  the  first  question  that  tanks  can  at  best  take 
out  only  a  portion  of  the  sludge  producing  elements  of  the  sewage.  The  effect  of 
tank  treatment  may  be  augmented,  however,  by  the  addition  of  chemicals.  In  the  past 
ten  years  chemical  methods  of  sewage  treatment  have  come  much  into  disfavor.  This 
has  been,  however,  principally  due  to  difficulties  with  the  resulting  large  volumes  of 
sludge.  Recently  in  the  Emscher  district  of  Germany  it  has  been  found  that  not 
only  do  Emscher  tanks  reduce  the  volume  of  ordinary  sludge,  but  that  they  also 
reduce  the  volume  of  sludge  resulting  from  chemical  treatment,  leaving  it  practically 
odorless  and  easily  drainable.  It  seems  to  me,  from  these  experiences,  that  attention 
might  profitably  again  be  focused  upon  chemical  methods. 

The  application  of  chemicals  to  the  sewage  of  New  York  City,  in  case  it  is  desired 
to  treat  the  sewage  within  the  city  limits,  will  be  very  easy.  It  will  simply  be  neces- 
sary to  add  the  chemical  or  chemicals  to  the  tank  influent.  The  effect  of  the  chem- 
icals will  take  place  during  the  passage  of  the  sewage  through  the  tanks.  This  effect 
will  consist  of  the  removal  of  that  part  of  the  suspended  matters  not  removed  by 
plain  sedimentation,  and  also  of  practically  all  of  the  colloidal  matters.  As  a  result 
of  this  higher  degree  of  solids  removal  the  sludge  remaining  in  the  tanks  will,  of 
course,  be  greater  in  volume.  Therefore,  if  chemicals  are  added  to  the  sewage,  the 
tanks  will  have  to  be  constructed  larger  than  the  preceding  figures  for  simple  sedi- 
mentation. In  order  to  give  a  conception  of  the  total  size  of  the  plants  in  this  case 
the  following  figures  are  given : 

Cubic  feet. 


Settling  Basin  Capacity,  as  before   5,200,000 

Sludge  Room  Capacity  1.25  cubic  feet  per  head  per  day  =  1.25  X  5,600,000  =  7,000,000 
Sludge  Produced,  0.23  liters  per  head  per  day. 

0.23X5,600,000  =  1,290,000  liters,  day. 
or    1,290,000-^28.32  =  45,600  cubic  feet,  day. 
or    45,600-^27         =  1,690  cubic  yards,  day. 


REPORT  OF  KARL  IMHOFF 


319 


These  figures  are,  of  course,  based  upon  assumptions,  and  might  be  modified  by 
local  conditions  to  a  large  extent.  A  large  factor  will  be  the  kind  of  chemical  used. 
In  the  Emscher  district  much  success  has  followed  the  use  of  wastes  from  the  iron 
industries.  I  am  not  able  to  say  what  would  be  the  best  chemical  for  New  York  to 
use,  and  experiments  will  have  to  be  made  to  determine  this,  taking  into  account  the 
relative  quantities  of  sludge  produced  and  the  costs  involved. 

The  apparatus  necessary  for  the  addition  of  chemicals  will  be  so  simple  and  take 
up  so  little  room  that  it  may  easily  be  installed  with  the  tank  under  the  street.  Ap- 
paratus for  the  introduction  into  the  sewage  of  compressed  air,  which  has  been  found 
of  advantage  in  some  cases  of  chemical  treatment  here,  may  also  easily  be  installed. 

If  such  chemical  treatment  is  combined  with  the  plain  tankage  there  is  no  doubt 
that  there  will  be  a  decided  improvement  in  the  effluent.  So  much  so  that  of  the 
standards  not  satisfied  by  simple  sedimentation,  Standard  No.  2,  referring  to  sludge 
deposits,  will  practically  then  be  satisfied,  mainly  because  if  chemical  treatment  is 
used  any  sedimentation  that  may  take  place  in  the  harbor,  as  a  result  of  the  intro- 
duction of  sewage,  will  be  mainly  due  to  secondary  precipitation  from  the  chemicals 
themselves.    Such  resulting  sludge  will,  however,  be  unobjectionable. 

It  is  doubtful  whether  Standard  No.  4,  referring  to  the  oxygen  content,  would  be 
satisfied  by  chemical  methods.  This  is  for  the  same  reasons  given  in  my  answer  to 
Question  No.  2.  With  chemical  precipitation  the  amount  of  liquid  sewage  introduced 
into  the  harbor,  which  is  the  factor  mainly  affecting  the  average  oxygen  content,  is 
practically  not  lessened.  I  am  convinced  that  there  is  no  known  method  of  sewage 
treatment  which  may  be  applied  within  the  limits  of  New  York  City  without  produc- 
ing a  nuisance,  which  will  satisfy  Standard  No.  4. 

If  it  is  decided  to  adopt  the  scheme  of  carrying  the  sewage  in  bulk  away  from  the 
city  to  some  point  on  the  sea-coast  and  there  purify  it  to  a  high  degree,  such  as  is  in- 
tended in  the  design  previously  mentioned  (Emscher  Tanks  and  Percolating  Filters), 
chemical  treatment  such  as  above  outlined  should  earnestly  be  considered  as  an  al- 
ternative.   In  this  case  the  plant  would  be  arranged  about  as  follows : 

Emscher  Tanks. 

Addition  of  Chemicals  (including  Hypochlorite  of  Lime,  if  necessary). 

Aeration. 

Rapid  Filtration. 

Such  a  plant  would  be  much  cheaper  in  construction  than  tanks  with  trickling 
filters  and  demand  much  less  area.  Besides,  such  a  plant  permits,  as  necessary,  any 
desired  degree  of  purification.  For  instance,  in  those  months  in  which  it  is  not  neces- 
sary the  final  treatment  may  be  omitted,  and  at  such  times  as  it  is  necessary  (as  in 
those  months  when  bathing  is  practiced)  a  high  degree  of  purification  may  be  ob- 
tained. This  is  a  decided  advantage  over  trickling  filters,  because  when  these  are 
used  the  degree  of  purification  attained  is  not  dependent  upon  the  will  of  the  oper- 
ator, but  upon  the  weather  conditions  and  other  non-controllable  factors. 

Karl  Imhoff. 

Essen,  Dec.  23,  1912. 


320 


REPORTS  OF  EXPERTS 


SECTION  IV 

DISCHARGE  OF  SEWAGE  INTO  THE  HARBORS  OF  BOSTON  AND  NEW 
YORK  AND  A  REPORT  BY  X.  H.  GOODNOUGH  ON  THE  CONDITIONS 
WHICH  LED  TO  THE  CONSTRUCTION  OF  THE  MAIN  DRAIN- 
AGE SYSTEMS  OF  BOSTON  AND  VICINITY 

For  30  years  Boston  harbor  has  been  protected  from  sewage  pollution  by  main 
drainage  works  and  for  nearly  half  this  period  many  of  the  cities  and  towns  in  its 
vicinity  have  been  united  in  a  thoroughly  coordinated  and  comprehensive  scheme  for 
the  sanitary  disposal  of  their  sewage. 

In  1912  the  sewage  of  about  300,000  persons,  in  addition  to  the  sewage  of  Boston, 
was  discharged  through  three  outlets  located  near  enough  to  the  open  waters  of  the 
sea  to  insure  a  disposal  of  the  wastes  by  tidal  action  and  digestion. 

Similarity  Between  Former  Conditions  in  Boston  and  Present  Conditions  in 

New  York 

In  many  respects  the  history  of  Boston  and  its  neighboring  municipalities  is 
capable  of  furnishing  an  instructive  object  lesson  to  New  York  City  and  up  to  a  cer- 
tain point  the  experience  of  the  two  cities  is  remarkably  alike.  The  conditions  which 
led  to  the  construction  of  the  Boston  main  drainage  works  were,  to  a  considerable 
extent,  similar  to  those  which  exist  at  the  present  time  in  New  York.  The  sewage, 
discharged  locally  through  numerous  outlets  into  the  restricted  waters  of  the  inner 
harbor,  caused  sludge  deposits  and  other  objectionable  consequences  and  the  gross  pol- 
lution of  certain  natural  tributaries  of  the  harbor  was  so  great  as  to  give  rise  to 
offensive  odors  in  the  summer  season.  It  was  impossible  to  trace  individual  cases 
of  disease  to  the  polluted  water,  but  prominent  physicians  declared  that  no  fact  was 
better  established  by  general  experience  than  that  foul  air  was  unfavorable  to  health 
and  gave  it  as  their  opinion  that  changes  in  the  sewerage  system  of  an  extended  char- 
acter, costing  large  sums  of  money,  could  alone  accomplish  practical  good. 

In  New  York  the  sewage  problem  has  been  the  subject  of  official  investigation 
for  eleven  years.  The  Boston  works  were  also  built  after  a  long  period  of  investigation. 
In  1870  the  consulting  physicians  addressed  to  the  city  authorities  a  remonstrance  to 
the  existing  conditions,  and  the  Boston  Board  of  Health,  established  in  1872,  constantly 
urged  improvements  in  their  reports.  In  1875  a  commission  of  experts  was  ap- 
pointed to  study  the  causes  of  the  objectionable  conditions  and  in  its  report  recom- 
mended the  construction  of  a  system  of  intercepting  sewers  to  intercept  the  flow  of 


REPORT  OF  X.  H.  GOODNOUGH  321 

the  numerous  sewers  discharging  into  waters  around  the  city  and  carry  it  to  a  single 
outlet  at  an  island  in  the  outer  harbor.  The  main  features  of  this  plan  were  ulti- 
mately adopted  in  the  construction  of  the  Boston  main  drainage  system  and  this  was 
the  beginning  of  the  entire  metropolitan  works  which  now  exist. 

It  is  worthy  of  note  that  like  New  York  various  protective  measures  were  first 
adopted,  such  as  extending  the  sewers  further  from  shore,  and  that  while  these  im- 
provements relieved  the  objectionable  conditions  for  a  time,  the  nuisances  soon  re- 
curred. It  was  not  until  comprehensive  works  were  carried  out  that  substantial 
and  lasting  improvement  was  obtained. 

The  objectionable  conditions  which  led  Boston  to  build  its  main  drainage  works 
were  not  confined  to  that  city.  In  the  densely  populated  cities  of  Cambridge,  Somer- 
ville,  Chelsea,  East  Boston,  etc.,  the  conditions  were  much  the  same  and  the  com- 
mission of  1875  considered  the  whole  territory  as  the  proper  field  for  its  investiga- 
tions. In  respect  to  its  scope,  the  Metropolitan  Sewerage  Commission  of  New  York 
has  also  considered  conditions  outside  of  New  York  and  in  its  report  of  April,  1910, 
reported  equally  upon  the  need  of  sewage  disposal  in  New  Jersey  and  New  York. 

Essential  Features  of  the  Boston  and  Metropolitan  Works 

The  City  of  Boston  proceeded  to  improve  its  own  sewerage  conditions  in  accord- 
ance with  an  act  of  the  Legislature  passed  in  1876.  It  took  eight  years  to  so  far 
complete  the  works  as  to  permit  sewage  to  be  discharged  from  the  Moon  Island  Works.* 

Following  the  Boston  City  Main  Drainage,  the  North  Metropolitan  Main  Drain- 
age works  were  put  into  service  in  1895  and  the  South  Metropolitan  works  in  1904. 
Twenty-four  cities  and  towns  now  discharge  their  sewage  through  these  three  outlets. 

The  best  method  of  disposing  of  the  sewage  of  the  North  Metropolitan  District 
was  made  the  subject  of  investigations.  Among  the  systems  considered  was  collection 
to  a  central  point  for  treatment  by  chemical  precipitation  and  discharge  into  the  inner 
harbor,  filtration  through  sand  on  an  extensive  area  of  marsh  land  and  the  separation, 
collection  and  treatment  of  the  sewage  of  each  community  and  discharge  into  the  local 
water  courses.  The  subject  was  finally  referred  to  the  State  Board  of  Health  which  in 
due  course  recommended  the  discharge  of  the  sewage  continuously  into  the  sea  at  Deer 
Island  light  at  the  entrance  of  Boston  harbor.  The  disposal  of  the  South  Metropolitan 
sewage  was  investigated  in  1899  and  1900  and  it  was  decided  to  discharge  it  at  Ped- 
dock's  Island,  which  lies  in  a  portion  of  the  harbor  which  is  unaffected  by  the  sewage 
from  the  other  main  outlets  and  where  strong  tidal  currents  are  available. 


*See  cut,  Boston  Main  Drainage,  Part  IV,  Chap.  II,  page  438. 


322  REPORTS  OF  EXPERTS 

The  total  quantity  of  sewage  discharged  into  Boston  harbor  through  the  three 
main  drainage  outlets  is  about  200,000,000  gallons  per  day.  At  Moon  Island,  where 
nearly  half  the  total  volume  is  disposed  of,  the  discharge  occurs  at  the  surface  of  the 
water  during  about  two  hours  of  the  outgoing  tide,  being  held  in  storage  basins  for 
the  remainder  of  the  time.  At  Deer  Island  and  Peddocks  Island,  each  of  which  re- 
ceives roughly  one-quarter  of  the  total,  the  sewage  is  discharged  continuously  after 
coarse  screening,  in  one  case  beneath  about  7  feet  and  in  the  other  beneath  about  30 
feet  of  water  at  low  tide.  Before  discharge  the  Moon  Island  sewage  passes  through 
deposit  sewers,  which  act  as  grit  chambers  and  remove  some  sand,  is  stored  for  some 
hours  in  the  outlet  tanks  and,  in  consequence  of  its  age,  is  somewhat  advanced  in 
decomposition;  the  Deer  Island  and  Peddocks  Island  sewage  is  fresher. 

The  sewage  discharged  from  Moon  Island  spreads  over  a  wide  area,  but  careful 
analyses  of  the  water  in  the  vicinity  show  little  trace  of  it  within  a  few  hours  after 
the  discharge  ceases.  Near  Deer  Island  and  Peddocks  Island  little  evidence  of  the 
sewage  can  be  detected  except  in  the  direct  line  of  the  sewage  flow.  No  harmful 
deposits  are  formed.  Odors  are  often  noticeable  for  a  considerable  distance  from  the 
Moon  Island  tanks  and  only  in  the  immediate  vicinity  of  the  other  outlets. 

Present  Sanitary  Condition  of  Boston  Harbor 

The  condition  of  Boston  harbor  as  respects  pollution  has  repeatedly  been  in- 
vestigated by  the  Massachusetts  State  Board  of  Health  and  many  instructive  reports 
have  been  made  upon  this  subject.  In  no  other  place  have  equal  facilities  existed 
for  the  study  of  the  behavior  of  sewage  when  discharged  into  sea  water,  and  by  none 
have  sewage  disposal  problems  received  more  thorough  and  authoritative  investiga- 
tion than  by  the  Massachusetts  State  Board  of  Health.  The  report  here  published 
by  Mr.  Goodnough,  Chief  Engineer  of  the  Board,  is  a  valuable  digest  of  the  essen- 
tial facts  relating  to  this  important  question  and  was  prepared  at  the  Commission's 
request  in  order  that  the  experience  gained  by  Boston  and  the  score  of  cities  and 
towns  in  its  vicinity  might  be  turned  to  useful  account  by  New  York. 

All  the  members  of  the  Metropolitan  Sewerage  Commission  have  visited  the  Bos- 
ton outfalls  and  are  familiar  with  the  condition  of  the  harbor  with  respect  to 
absence  of  visible  pollution. 

In  the  summer  of  1911  the  Commission's  floating  laboratory  was  sent  to  make  a 
study  of  the  dissolved  oxygen  in  the  water.  The  data  collected  on  this  expedition  have 
been  published  in  the  Commission's  Report  of  August,  1912,  pages  372-392.  The 
analyses  show  that  the  harbor  waters  contained  very  much  higher  percentages  of 
dissolved  oxygen  than  are  found  in  New  York  harbor  except  in  certain  localities, 


REPORT  OP  X.  H.  GOODNOUGH  323 

notably  the  mouths  of  the  Charles,  Mystic  and  Chelsea  rivers,  where  some  sewage 
outfalls  have  not  yet  been  connected  with  the  main  drainage  systems. 

Except  in  the  locations  mentioned  the  water  of  the  inner  harbor  generally  con- 
tained nearly  its  saturation  value  of  oxygen  and  the  water  of  the  outer  harbor  was 
almost  saturated  with  oxygen  except  in  the  immediate  vicinity  of  the  three  sewer  out- 
falls. Surface  samples  collected  50,  100  and  500  feet  southeast  of  the  Deer  Island 
light,  which  is  very  near  the  point  of  discharge,  contained  92-93  per  cent,  of  oxygen, 
but  samples  from  greater  depths  contained  99-100  per  cent.  The  poorest  sample  col- 
lected at  the  surface  within  10  feet  of  the  outlet  contained  53  per  cent.,  but  a  sample 
from  a  point  7  feet  below  was  88  per  cent,  saturated.  These  were  the  poorest  of  35 
samples  taken  close  to  this  outlet. 

Of  109  samples  taken  near  Peddocks  Island  outlet,  the  lowest  in  oxygen  contained 
83  per  cent,  and  most  held  95  per  cent,  or  more.  Many  samples  taken  immediately 
over  the  outlet  contained  about  90  per  cent,  of  dissolved  oxygen.  These  samples 
contained  so  much  salt  water  that  it  was  evident  the  sewage  was  well  diffused  before 
reaching  the  surface. 

Ninety-one  samples  were  taken  at  and  near  the  Moon  Island  outlet.  Some 
samples  collected  from  the  surface  500  and  1000  feet  from  the  point  of  outfall  con- 
tained 68  per  cent.,  others  at  a  mile  distant  held  75  per  cent,  and  many  others  con- 
tained somewhat  more.  There  was  always  less  oxygen  at  the  surface  where  the  sew- 
age was  densest  than  at  points  below.  Such  pollution  as  was  produced  in  the  outer 
harbor  was  confined  to  the  surface,  so  far  as  the  oxygen  analyses  could  determine. 

Two  facts  brought  out  in  the  Commission's  Boston  harbor  investigation  deserve 
to  be  mentioned  for  their  bearing  on  the  disposal  of  sewage  through  dilution  in 
Boston  and  New  York.  First,  the  water  in  Boston  harbor  was  much  more  salt  than 
is  New  York  harbor  water.  Whereas  Upper  New  York  bay  and  the  Lower  East  river 
ordinarily  contain  equal  parts  of  sea  water  and  land  water,  only  about  6-8  per  cent, 
of  the  water  in  Boston  harbor  is  derived  from  the  land.  Second,  the  temperature  of 
the  water  at  Boston  was  15.5-19  degrees  C,  and  in  the  Lower  East  river  22-23 
degrees  C.  At  Boston  the  temperature  and  salinity  were  practically  that  of  the  sea 
water. 


324 


REPORTS  OP  EXPERTS 


REPORT  OF  X.  H.  GOODNOUGH 

To  the  President  and  Members  op  the  Metropolitan  Sewerage  Commission  op 
New  York: 

Gentlemen  :  The  sewers  of  the  city  of  Boston  were  constructed  originally  with 
the  object  of  draining  cellars  and  lands.  The  contents  of  privy  vaults,  and  even 
liquid  from  them,  were  excluded,  but  they  received  the  wastes  from  kitchen  sinks  and 
rain  water  from  roofs  and  yards.  They  were  built  by  a  private  enterprise,  but  when 
the  city  obtained  a  charter  in  1823  one  of  the  first  acts  of  the  city  government  was 
to  assume  the  control  of  all  existing  sewers  and  to  build  and  care  for  the  new  ones. 

A  general  water  supply  was  introduced  in  1848,  but  for  many  years  no  water- 
closets  were  connected  with  the  sewers  and  fecal  matters  were  rigidly  excluded  from 
them.  As  late  as  1857  there  were  only  6,500  waterclosets  in  use  in  the  city,  but  after 
that  date  they  multiplied  rapidly  and  the  number  reached  100,000  or  more  in  1885. 

The  agitation  for  a  better  system  of  sewage  disposal  appears  to  have  been  begun 
in  1870.  Early  in  that  year  the  consulting  physicians  of  the  city  of  Boston  addressed 
to  the  city  authorities  a  remonstrance  to  the  then  existing  sanitary  conditions  of 
the  city,  in  which  they  declared  the  urgent  necessity  of  a  better  system  of  sewerage, 
stating  that  it  would  be  a  work  of  time,  of  great  cost,  etc.  The  board  of  health  of 
the  city,  established  in  1872,  beginning  with  its  earliest  reports,  constantly  urged  an 
improvement  in  the  system  of  sewerage.  In  their  report  of  1874  to  the  City  Council 
the  objectionable  conditions  resulting  from  a  faulty  system  of  sewerage  and  sewage 
disposal,  are  described  at  length,  and  from  that  report  the  following  extract  is  taken : 

Although  in  our  annual  report  of  1873,  and  again  in  1874,  we  called  the 
attention  of  your  honorable  body  to  the  great  importance  of  a  change  in  our  sys- 
tem of  sewerage,  we  deem  it  of  such  vital  importance  to  the  health  and  comfort 
of  the  city  at  large,  but  more  especially  to  certain  portions  of  it,  that  we  venture 
again  to  urge  the  subject  in  a  special  communication. 

There  are  several  places  in  which  the  evil  is  already  so  great  that  we  men- 
tion them  in  particular. 

First — The  old  Roxbury  canal,  crossing  under  Albany  street,  near  Chester 
Park. 

Second — The  Stony  brook  sewer,  discharging  upon  the  Back  bay  flats. 
Third— The  Muddy  brook  sewer,  between  Brookline  avenue  and  Downer 
street,  in  Ward  15. 

Roxbury  canal,  so  called,  leads  in  from  the  South  bay,  is  about  fifty  feet 
wide  and  two  thousand  feet  long,  reaching  nearly  to  Harrison  avenue.  The  tide 
flows  in  and  out  but  sluggishly.  Into  this  three  or  four  large  sewers  pour  their 
contents,  and  when  the  tide  recedes  there  is  left  but  very  shoal  filthy  water, 
through  which  the  foul  gases  from  the  putrid  bottom  can  be  seen  bubbling  into 
the  atmosphere.  At  low  tide  a  considerable  portion  of  this  filthy  bottom  is  left 
bare,  giving  off  the  most  sickening  and  even  dangerous  effluvia  into  a  thickly 
populated  neighborhood.  In  Northampton  street,  Chester  Park,  Springfield  street, 
Harrison  avenue,  Albany  street,  and  especially  at  the  City  Hospital,  where  there 
is  a  daily  average  of  230  patients  who  require  pure  air,  the  stench  from  the  Rox- 
bury canal  is  often  observed  and  exceedingly  annoying. 


REPORT  OF  X.  H.  GOODNOUGH 


325 


The  Stony  brook  sewer,  which  conveys  the  sewage  of  more  than  half  of  the 
former  city  of  Roxbury,  of  now  about  thirty  thousand  inhabitants,  terminates  at 
the  west  side  of  Parker  street,  where,  at  low  tide,  this  immense  sewage  is  left  to 
trickle  over  the  muddy  flats,  about  one  hundred  acres  in  extent,  to  the  Charles 
river  beyond.  Before  this  sewage  has  reached  a  point  where  it  can  diverge  from 
the  wharves  of  the  city,  it  will  have  traveled  more  than  one-half  of  the  circumfer- 
ence of  the  city  proper,  catching  at  the  bridges,  wharves  and  upon  the  flats  in  its 
course. 

An  order  has  recently  been  passed  by  the  City  Council  to  extend  the  channel 
of  the  Stony  brook,  so  as  to  prevent  the  discharge  of  the  sewerage  upon  the  flats 
next  Parker  street. 

In  addition  to  the  Stony  brook  sewer,  there  are  eight  others  opening  into 
Charles  river  above  Cambridge  bridge,  which,  with  their  open  mouths  at  low  tide 
discharging  their  gases  into  the  atmosphere,  and  their  contents  into  shoal  water 
or  upon  flats,  are  doing  a  great  share  in  making  the  atmosphere  of  that  part  of  the 
city  skirting  the  river  and  Back  bay,  at  times,  absolutely  unfit  to  breathe. 

The  Muddy  brook  sewer  coming  from  Brookline  is  very  large,  opens  under 
Brookline  avenue,  near  Tremont  street,  and  is  then  an  open  sewer  in  the  imme- 
diate rear  of  dwelling-houses  between  Brookline  avenue  and  Downer  street  for  a 
distance  of  600  feet,  and  then  crosses  the  avenue  again  into  the  town  of  Brookline. 
The  water  in  this  brook  gets  very  low  in  summer,  leaving  but  little  besides  the 
sewage  matter  to  flow  through  it.  The  stench  from  this  is  very  bad,  and  the 
people  who  live  near  it  justly  complain.  This  sewer  ought  to  be  covered  at  once, 
for  a  distance  of  about  600  feet,  to  prevent  evil  results  which  must  inevitably 
come  from  its  present  condition. 

The  places  mentioned,  although  the  worst,  are  not  all  to  which  we  invite  at- 
tention. The  city  proper,  being  nearly  surrounded  by  tide  water  and  flats,  is  to 
the  same  extent  literally  fringed  with  the  open  mouths  of  sewers,  discharging 
their  gases  into  the  atmosphere,  and  their  other  contents  upon  the  shoals,  which 
are  left  bare  next  the  sea-wall  and  under  the  wharves  by  the  receding  tide. 

The  result  is,  that  at  low  tide,  and  especially  in  summer,  about  the  wharves 
and  skirts  of  the  city,  where  thousands  of  the  laboring  class  must  work  during 
the  day,  and  many  more  will  resort  for  a  cool  breeze  in  the  evening,  the  air,  in- 
stead of  being  pure  and  cool  from  the  water,  as  it  should  be,  is  polluted  and 
made  dangerous  by  the  foul  breath  of  the  sewers. 

That  our  prevalent  summer  diseases  are  largely  influenced  by  this  poisoned 
atmosphere  there  can  be  no  sort  of  doubt. 

From  the  reports  of  the  board  of  health,  the  writings  of  various  physicians  and 
the  reports  of  committees  of  the  city  council,  and  especially  of  a  commission  of  ex- 
perts appointed  in  1875  to  study  the  whole  question  of  the  causes  of  the  objectionable 
conditions,  it  is  possible  to  determine  quite  definitely  the  causes  which  made  neces- 
sary the  construction  of  an  improved  system  of  sewerage. 

In  addition  to  the  objectionable  conditions  caused  by  the  sewer  outlets  and  the 
method  of  disposal  of  the  sewage,  the  sewers  themselves  were  also  objectionable,  on 
account  of  their  design,  their  location  and  lack  of  ventilation,  and  also  on  account 
of  the  faulty  method  of  trapping  and  ventilating  the  house  drains;  but,  except  as 
these  conditions  were  aggravated  by  the  method  of  disposal  and  the  circumstances 


326 


REPORTS  OF  EXPERTS 


affecting  the  sewer  outlets,  the  objectionable  conditions  resulting  from  them  are 
separable  from  those  due  to  the  method  of  disposal  of  the  sewage  and  need  not  be 
considered  here. 

The  commission  of  1875,  after  a  careful  investigation  of  the  whole  subject, 
recommended  the  construction  of  a  system  of  intercepting  sewers,  to  intercept  the  flow 
of  the  numerous  sewers  discharging  into  waters  around  the  city  and  convey  it  to  a 
single  outlet  into  the  harbor,  and  the  main  features  of  this  plan  were  ultimately 
adopted  in  the  construction  of  the  Boston  main  drainage  system. 

The  board  of  health  in  its  report  for  the  year  ending  April  30,  1878,  describes  the 
nuisances  caused  by  sewage  and  presents  a  map  showing  the  location  of  the  principal 
sewer  outlets  and  the  areas  of  flats  on  which  the  sewage  had  accumulated.  From 
these  outlets  and  areas  it  appears  that  foul-smelling  gases  and  odors  were  diffused 
for  long  distances  in  hot  weather  under  certain  conditions  of  the  atmosphere.  At 
times  a  well-defined  sewage  odor  would  extend  over  the  whole  south  and  west  ends 
of  the  city. 

Complaints  of  bad  odors  have  been  made  more  frequently  during  the  past 
year  than  ever  before. 

They  have  come  from  nearly  all  parts  of  the  city,  but  especially  and  seriously 
from  the  South  and  West  Ends. 

Large  territories  have  been  at  once,  and  frequently,  enveloped  in  an  atmos- 
phere of  stench  so  strong  as  to  arouse  the  sleeping,  terrify  the  weak  and  nauseate 
and  exasperate  nearly  everybody. 

It  has  been  noticed  more  in  the  evening  and  by  night  than  during  the  day, 
although  there  is  no  time  in  the  whole  day  when  it  may  not  come. 

It  visits  the  rich  and  the  poor  alike.  It  fills  the  sick-chamber  and  the  office. 
Distance  seems  to  lend  but  little  protection.  It  travels  in  a  belt  half-way  across 
the  city,  and  at  that  distance  seems  to  have  lost  none  of  its  potency,  and,  al- 
though its  source  is  miles  away,  you  feel  sure  it  is  directly  at  your  feet.  *  *  * 

The  sewers  and  sewage-flats  in  and  about  the  city  furnish  nine-tenths  of  all 
the  stenches  complained  of. 

They  are  much  worse  each  succeeding  year,  and,  although  so  loathsome  this 
season,  we  can  but  predict  that,  for  several  reasons,  they  will  be  much  worse 
next  year  than  this. 

The  accumulation  of  sewage  upon  the  flats  and  about  the  city  has  been  and 
is  rapidly  increasing  until  there  is  not  probably  a  foot  of  mud  in  the  river,  in  the 
basins,  in  the  docks,  or  elsewhere,  in  close  proximity  to  the  city,  that  is  not  fouled 
with  sewage. 

The  board  closes  its  report  by  urgently  recommending  the  construction  of  a  sys- 
tem of  sewerage  to  relieve  the  nuisances  then  existing  about  the  city,  but  as  no  system 
was  then  under  way  various  palliative  measures  were  adopted  by  extending  the  sew- 
ers, filling  some  of  the  objectionable  channels  and  covering  some  of  the  more  offensive 
flats.  While  these  improvements  relieved  the  objectionable  conditions  for  a  time,  sub- 
sequent reports  show  that  the  nuisances  soon  recurred. 

In  the  report  for  1882-3  appears  the  following  statement: 

It  must  be  apparent,  however,  to  those  who  have  observed  at  all,  as  well  as 
to  those  who  are  suffering  from  it,  that  the  further  deposit  of  sewage  in  Charles 
river,  in  the  Back  Bay,  in  the  South  Bay,  on  the  shores  of  South  Boston,  in  the 
docks  or  elsewhere,  the  stench  from  which  at  low  tide  is  almost  unbearable,  is,  to 


REPORT  OF  X.  H.  GOODXOUGH 


327 


say  the  least,  to  be  deplored.  Even  at  a  considerable  distance  from  these  places 
the  stench  is  already  so  great  as  at  times  to  awaken  persons  from  sleep,  and  we 
cannot  doubt  that  it  is  directly  the  cause  of  considerable  sickness. 

In  addition  to  the  urgent  recommendations  of  the  board  of  health  the  physicians 
of  the  city  in  numerous  hearings  urged  an  improvement  in  the  system  of  sewage  dis- 
posal. A  few  brief  quotations  from  the  statements  of  a  few  of  the  prominent  physi- 
cians will  indicate  their  opinion  as  to  the  conditions  existing  at  the  time: 

In  the  presence  of  an  hourly  poison  such  as  the  air  undergoes  the  death  rate 
cannot  fail  to  be  raised  and  medical  measures  for  the  preservation  of  the  public 
health  will  have  but  little  effect. 

My  views  are  that  it  (i.  e.,  a  change  in  our  system  of  sewerage)  is  of  such 
necessity  and  should  be  of  such  an  extended  character  that  the  expenditure  of 
an  immense  amount  of  money,  say  several  millions  of  dollars,  can  alone  accom- 
plish any  practical  good. 

It  is  impossible  to  cite  individual  cases  of  disease  which  are  distinctly  owing 
to  bad  drainage.  I  do  not  know  that  I  ever  saw  such,  but  there  is  no  fact  better 
established  by  general  experience  than  that  foul  air  is  unfavorable  to  health. 
That  the  whole  atmosphere  of  the  city  has  through  imperfect  drainage  become 
at  times  too  foul  for  endurance  is  too  patent  a  fact  for  any  one  to  dispute  and 
should  take  precedence  in  the  public  attention  before  any  other  object  of  public 
interest. 

The  original  city  of  Boston  was  built  on  a  series  of  hills  and  had  an  area  of 
about  700  acres,  or  a  little  over  a  square  mile.  The  grades  were  steep,  and  while 
the  older  drains  were  poorly  built,  they  had  good  grades  and,  as  they  received  but 
little  sewage,  appear  to  have  caused  but  little  trouble.  With  the  growth  of  the  city 
large  areas  of  land  all  about  it  were  reclaimed  from  the  sea  by  filling  the  flats  about 
the  shores,  but  the  reclaimed  land  was  filled  to  elevations  but  little  above  high  water, 
and  the  streets  traversing  the  filled  areas  were  often  not  over  7  feet  above  that  ele- 
vation. A  large  proportion  of  the  house  basements  and  cellars  in  these  filled  lands 
were  below  high  water  and  many  of  them  but  from  5  to  7  feet  above  low-water  mark. 
The  house  drains  in  many  cases  were  laid  under  the  cellar  floors  and  with  the  neces- 
sary fall  in  the  drains  and  sewers  the  outlets  of  the  sewers  were  rarely  much  if  any 
above  low  water. 

As  the  lands  were  filled  the  sewers  were  extended  to  new  outlets  across  the  filled 
portions  with  comparatively  slight  fall.  The  average  rise  and  fall  of  the  tide  at  Boston 
is  10  feet,  and  in  consequence  of  the  conditions  above  outlined,  the  contents  of  the 
sewers  were  dammed  back  by  the  tide  during  the  greater  part  of  each  twelve  hours. 
To  prevent  the  salt  water  flowing  into  them,  many  of  them  were  provided  with  tide 
gates,  which  closed  as  the  sea  rose  above  the  level  of  the  sewage  and  excluded  the 
tide  water.  These  tide  gates  also  shut  in  the  sewage,  and.  there  being  no  current,  the 
solid  matters  were  deposited.  To  afford  storage  for  the  accumulated  sewage,  many  of 
the  sewers  were  built  very  much  larger  than  would  otherwise  have  been  necessary 
and  rectangular  shapes  were  used  instead  of  the  curved  inverts  now  almost  always 
employed.  As  the  tide  receded,  the  tide  gates  opened  under  ordinary  conditions  a 
short  time  before  low  water  and  the  sewage  escaped,  but  it  almost  immediately  met 
the  incoming  tide  and  was  brought  back  to  form  deposits  upon  the  flats  and  shores 
about  the  city. 


328 


REPORTS  OP  EXPERTS 


Of  the  large  amount  of  sewage  which  flowed  into  Stony  brook,  into  the  Back 
Bay,  and  into  South  Bay  between  Boston  and  South  Boston,  it  is  asserted  that  hardly 
any  was  carried  away  immediately  from  the  vicinity  of  the  dense  populations  in  those 
sections. 

The  objectionable  conditions  complained  of  about  the  city  of  Boston  were  not 
confined  to  that  city.  In  the  densely  populated  cities  of  Cambridge,  Somerville,  Chel- 
sea, East  Boston,  etc.,  on  the  north  side  of  the  Charles  river,  the  conditions  were 
much  the  same  as  about  the  city  of  Boston  on  the  south  side  of  the  river,  and  the 
Commission  of  1875  considered  both  the  sewerage  of  the  city  of  Boston  and  of  the 
Metropolitan  areas  north  of  the  city.  The  city  of  Boston,  however,  did  not  await  the 
action  of  those  cities  but  proceeded  with  the  construction  of  its  own  system  under  an 
act  passed  in  1876,  entitled  "An  Act  to  empower  the  city  of  Boston  to  lay  and  main- 
tain a  main  sewer,  discharging  at  Moon  Island  in  Boston  Harbor,  and  for  other  pur- 
poses." The  works  were  so  far  completed  that  the  discharge  of  the  sewage  of  the  city 
at  Moon  Island  was  begun  January  1,  1884. 

Summary 

The  foregoing  review  of  the  conditions  existing  before  the  construction  of  the 
Boston  main  drainage  system  was  begun  shows  that  the  principal  causes  which  made 
necessary  the  construction  of  a  general  system  of  sewage  disposal  were  the  following : 

1.  The  great  nuisances  caused  by  the  deposits  of  sewage  upon  the  flats  along 
Stony  brook,  Charles  river,  the  Roxbury  canal  and  the  South  bay. 

2.  The  nuisances  caused  by  the  sewers  discharging  into  the  docks  and  about  the 
wharves  where  the  tidal  currents  of  the  harbor  were  not  effective  for  the  dilution  and 
removal  of  the  sewage. 

3.  The  gross  pollution  of  certain  local  waters,  such  as  Stony  brook  and  the  Rox- 
bury canal,  portions  of  the  South  bay,  where  the  quantity  of  sewage  was  so  great  in 
proportion  to  the  quantity  of  water  that  the  entire  quantity  of  water  was  polluted  to 
such  an  extent  as  to  become  offensive  in  the  summer  season. 

4.  The  low  level  of  large  areas  of  filled  lands  about  the  city,  on  which  houses 
had  been  constructed  at  so  slight  an  elevation  above  high  tide  that  much  difficulty 
was  experienced  from  the  flooding  of  cellars  and  from  inefficient  operation  of  the 
sewers  at  times  of  storms  and  of  extraordinary  high  tides.  These  objectionable  con- 
ditions were  especially  noticeable  in  the  large  areas  adjoining  what  was  formerly  the 
neck  of  the  peninsula  leading  from  Boston  to  Roxbury,  especially  the  region  border- 
ing the  westerly  side  of  South  bay,  in  what  is  now  known  as  the  South  End  of  the 
city  of  Boston. 

The  Boston  Main  Drainage  System,  the  Purpose  for  Which  It  Was  Designed 

and  the  Results  Achieved 

The  sewers  of  the  city  of  Boston  were  all  constructed  upon  the  combined  plan ; 
that  is,  they  received  both  the  domestic  and  manufacturing  sewage  of  the  city  and 
the  water  draining  from  streets,  roofs  and  yards  at  times  of  rain.  The  removal  of 
all  the  flow  in  the  sewers  when  increased  by  rain  water  or  melting  snow  would  have 
required  works  of  such  enormous  size  as  to  have  been  impracticable.  It  was  also  im- 
practicable to  separate  the  sewage  from  the  storm  water  within  a  reasonable  time  ex- 
cept at  a  great  and  excessive  cost. 


REPORT  OF  X.  H.  GOODNOUGH 


329 


The  plan  finally  adopted  was :  To  construct  a  system  of  intercepting  sewers  along 
the  margins  of  the  city,  to  receive  the  dry  weather  flow  of  the  existing  sewers ;  a  main 
sewer  into  which  the  intercepting  sewers  discharge,  and  which,  crossing  the  southerly 
part  of  the  city,  leads  to  a  pumping  station,  from  which  the  sewage  is  pumped  to  a 
reservoir  on  Moon  Island  in  the  southerly  part  of  the  harbor,  whence  it  is  discharged 
into  the  sea  during  the  first  two  hours  of  the  outgoing  tide.  At  the  times  the  works 
were  designed  the  sewage  of  the  city  was  discharged  through  seventy  or  more  different 
outlets  about  the  shores  of  the  harbor  and  rivers.  These  sewers  were  connected  with 
the  intercepting  sewers  by  means  of  connections  of  sufficient  size  to  carry  somewhat 
more  than  the  ordinary  flow  of  sewage  when  not  increased  by  rain  water  or  melting 
snow.  The  old  sewer  outlets  were  retained,  however,  and  whenever  the  flow  of  the 
sewers  is  increased  by  rain  or  melting  snow  beyond  the  capacity  of  the  intercepting 
sewers  to  remove  it,  the  excess  overflows  through  these  outlets. 

It  was  estimated  that  a  large  portion  of  the  southerly  part  of  the  city  could  event- 
ually be  drained  by  a  gravity  sewer  alone  to  some  suitable  point  of  outlet  in  the  harbor 
without  the  necessity  of  pumping,  but  about  12  square  miles  of  the  city  were  too  low 
to  be  served  by  such  a  sewer  and  the  system  was  made  of  sufficient  size  to  care  for 
about  15  square  miles,  so  as  to  allow  for  its  use  until  the  high-level  sewer  was  built. 
Provision  was  also  made  for  admitting  a  rainfall  amounting  to  about  one-fourth  of 
an  inch  an  hour  over  the  whole  district,  and  the  quantity  that  would  be  carried  was 
of  course  larger  in  the  earlier  years  of  the  works  and  gradually  grew  less  as  the 
capacity  of  the  system  was  reached.  It  has  now  been  relieved  by  the  construction  of 
the  high-level  sewer,  so  that  the  quantity  of  rainfall  removed  by  the  system  is  prob- 
ably fully  as  large  as  the  amount  originally  proposed. 

The  system  was,  however,  designed  to  favor  the  removal  of  storm  water  from 
certain  low-lying  districts  in  the  southern  part  of  the  city,  where  drainage  was  poor, 
as  has  already  been  mentioned,  and  at  times  of  heavy  rain  the  entire  drainage — both 
storm  water  and  sewage — from  three  or  four  of  these  very  low  districts  is  cared  for 
by  the  main  drainage  system.  The  favoring  of  these  districts  tends  to  throw  a 
greater  proportion  of  sewage  through  the  overflow  outlets  of  other  districts  into  the 
waters  about  the  harbor  at  times  of  rain  than  would  otherwise  be  the  case,  but  thus 
far,  except  in  a  very  few  instances,  seriously  objectionable  conditions  have  not  re- 
sulted therefrom. 

The  Boston  main  drainage  system  was  completed  in  1884  and  first  operated  on 
January  1  of  that  year.  Connections  had  already  been  prepared  and  by  February, 
1884,  nearly  all  of  the  city  sewage  was  diverted  from  the  old  outlets  to  the  new  out- 
let at  Moon  Island. 

As  elsewhere  stated,  the  main  drainage  works  were  designed  and  built  to  correct 
certain  evils  inherent  in  the  former  system  of  sewerage  and  especially  of  sewage  dis- 
posal. These  were :  First,  the  damming  up  of  the  common  sewers  by  the  tide,  by  which 
for  much  of  the  time  they  were  converted  into  stagnant  cesspools  and  the  air  in  them 
was  compressed  and  to  find  outlets  was  driven  into  house  drains  and  other  openings; 
second,  the  discharge  of  sewage  on  the  shores  of  the  city  in  the  immediate  vicinity  of 
population,  thereby  causing  nuisances  at  many  points.  These  nuisances  were  partly 
at  the  wharves  and  docks,  partly  from  sewage  covered  flats  exposed  at  low  water  and 


330 


REPORTS  OF  EXPERTS 


partly  from  the  gross  pollution  of  certain  local  waters,  such  as  Stony  brook,  Rox- 
bury  canal,  South  bay,  etc.  Finally,  the  system  was  intended  to  relieve  flooding  in 
low  portions  of  the  city  at  times  of  storm.  The  results  of  its  working,  as  regards  the 
removal  of  the  evils  above  referred  to,  are  summarized  as  follows : 

The  first  of  these  evils  has  been  entirely  corrected  by  the  new  system.  The 
old  sewers  now  have  a  continual  flow  in  them,  independent  of  the  stage  of  the 
tide,  as  has  been  ascertained  by  frequent  observations,  and  also  from  the  testi- 
mony of  drain-layers,  who  formerly  were  only  able  to  enter  house-pipes  into  the 
sewers  when  the  latter  were  empty  at  low  tide,  but  now  can  make  such  connec- 
tions at  any  time. 

The  new  system  has  also  substantially  remedied  the  second  evil.  From  the 
moment  that  any  of  the  city  sewers  was  connected  with  an  intercepting  sewer,  the 
sewage  which  had  before  discharged  on  the  shore  of  the  city  was  diverted,  and  has 
since  been  conveyed  to  Moon  Island  and  emptied  into  the  Outer  Harbor  at  that 
point. 

It  is  true  that  about  twenty-four  times  during  the  past  year,  or  an  average 
of  twice  a  month,  during  rain  storms  and  freshets,  the  amount  of  water  flowing 
in  the  sewers  has  exceeded  the  capacity  of  the  pumps.  At  such  times  the  excess 
has  been  discharged  at  the  old  sewer  outlets.  But  this  occasional  and  temporary 
discharge  of  very  dilute  sewage  does  not  seem  to  have  occasioned  any  nuisance. 
Examinations  and  inquiries  concerning  the  condition  of  the  shores  and  docks  at 
the  sewer  outlets  have  shown  that  water,  once  continually  foul,  has  become  pure, 
bad  odors  have  ceased,  and  fish  have  returned  to  places  where  none  had  been 
seen  for  years.  The  stenches  referred  to  by  the  City  Board  of  Health,  which 
formerly,  at  times,  were  prevalent  over  the  city,  were  not  noticed  during  the  past 
year. 

The  attempt  to  relieve  certain  low  districts,  subject  to  flooding  of  cellars 
during  rain-storms  at  high  tide,  by  discriminating  in  favor  of  such  districts  in 
respect  to  the  interception  of  stormwater,  has  met  with  marked  success.  No  case 
of  flooding  in  such  districts  has  been  reported  since  the  sewers  draining  them 
have  been  connected  with  the  intercepters ;  and  many  cellars,  which  used  often 
to  be  filled  several  feet  deep  with  water,  are  known  to  have  been  perfectly  dry 
during  the  past  year. 

Building  the  intercepting  sewers  has  also  dried  cellars  in  other  parts  of  the 
city  in  a  way  which  was  not  at  first  anticipated.  When  land  on  the  shores  of  the 
city  was  reclaimed  for  building  purposes,  most  of  the  old  walls  and  wharves  were 
covered  up  by  the  new  filling.  Tide-water  followed  along  any  such  structures 
through  the  ground,  and  entered  cellars  lower  than  high-tide  level.  The  new 
sewers  were  generally  built  along  the  present  margins  of  the  city,  and  in  dig- 
ging deep  trenches  for  them  the  old  structures  found  were  cut  off  and  removed. 
The  backfilled  earth  in  the  trenches  forms  an  impervious  dam  surrounding  the 
city,  beyond  which  tide-water  cannot  pass. 

The  system  was,  as  a  whole,  admirably  adapted,  as  its  workings  have  shown,  for 
the  removal  of  the  nuisances  formerly  complained  of  and  for  the  relief  from  the  other 
objectionable  conditions  so  long  a  source  of  annoyance  and  injury  throughout  a  large 
part  of  the  city. 


REPORT  OF  X.  H.  GOODNOUGH 


331 


Metropolitan  Sewerage  Systems  and  Reasons  Which  Led  to  Their  Construction 

The  Boston  main  drainage  system  now  drains  a  territory  of  about  15  square 
miles,  which  will  be  reduced  to  about  12  square  miles  in  the  future.  As  already  stated, 
this  system  was  put  in  operation  on  January  1,  1884.  The  North  Metropolitan  sewer- 
age system  is  also  shown  on  the  accompanying  map*  and  is  colored  brown.  This  system 
was  first  operated  in  1895. 

The  reasons  which  led  to  its  construction  are  much  the  same  as  those  which  lead 
to  the  construction  of  the  Boston  main  drainage  system.  The  sewage  of  many  of  the 
cities,  towns  and  districts,  including  Cambridge,  Somerville,  Chelsea,  Charlestown  and 
East  Boston  was  discharged  at  numerous  outlets  into  the  local  waters  and  created 
serious  nuisances.  Many  of  the  towns  further  inland  had  no  sewerage  systems  and, 
though  sewerage  was  badly  needed,  it  was  impracticable  to  provide  outlets  which  would 
not  be  likely  to  create  very  objectionable  conditions.  There  was,  furthermore,  a  large 
number  of  manufacturing  establishments  in  those  districts  of  kinds  which  produced 
large  quantities  of  very  foul  wastes,  among  which  were  numerous  tanneries  and  large 
slaughter  houses  and  meat-packing  establishments. 

The  investigations  as  to  the  best  method  of  disposing  of  the  sewage  in  this  valley 
extended  over  several  years.  Various  systems  were  considered,  including  the  collec- 
tion of  the  sewage  at  some  point  near  the  lower  end  of  the  valley  and  its  disposal,  after 
chemical  precipitation,  by  discharging  it  near  the  mouth  of  the  Mystic  River,  and  a 
plan  for  filtering  it  through  sand  on  an  extensive  area  of  marsh  land  in  the  towns 
of  Revere  and  Saugus.  The  question  of  treating  the  sewage  of  each  community 
separately  and  discharging  it  subsequently  into  local  waters  was  also  carefully 
considered. 

The  whole  matter  was  finally  referred  to  the  State  Board  of  Health  in  1887  and 
all  of  the  various  methods  of  sewage  disposal  for  this  district  again  carefully  con- 
sidered, and  its  report,  submitted  to  the  Legislature  in  1889,  recommended  the  dis- 
charge of  the  sewage  continuously  into  the  sea  at  Deer  Island  Light  at  the  entrance  to 
Boston  harbor. 

In  the  lower  part  of  the  North  Metropolitan  district,  where  sewerage  systems 
were  already  in  existence  at  the  time  the  Metropolitan  system  was  constructed,  the 
sewers  had  been  built  for  the  most  part  upon  the  combined  plan  and  received  both 
sewage  and  storm  water.  In  making  the  connections  between  these  sewers  and  the 
Metropolitan  sewers  the  same  rule  was  followed  as  in  the  case  of  the  Boston  main 
drainage  system,  i.  e.,  the  dry  weather  flow,  together  with  a  certain  proportion  of  the 
storm  water  at  times  of  rain,  was  taken  into  the  sewers  and  the  excess  flow  at  times  of 
storm  over  the  capacity  of  the  Metropolitan  sewers  was  allowed  to  discharge  at  the 
former  sewer  outlets.  In  the  districts  where  no  sewerage  systems  were  in  existence 
previous  to  the  construction  of  the  Metropolitan  system  the  sewers  were  built  upon  the 
separate  plan  and  storm  water  rigidly  excluded,  since  it  could  be  discharged  into 
local  waters  without  objection. 

South  Metropolitan  Sewerage  System 

The  South  Metropolitan  sewerage  system  was  established  in  1899  and  comprises 
the  higher  parts  of  the  city  of  Boston  south  of  the  area  served  by  the  Boston  main 
drainage  system,  together  with  the  thickly  settled  portions  of  the  valleys  of  the  Charles 

•Not  reproduced.    See  cut,  Part  IV,  Chap.  II,  page  438. 


332 


REPORTS  OF  EXPERTS 


and  Neponset  rivers.  Parts  of  this  district  had  for  many  years  been  tributary  to  the 
Boston  main  drainage  works,  which  was  designed  of  sufficient  size  to  serve  these  dis- 
tricts for  several  years  after  its  completion.  When,  however,  the  Boston  main  drain- 
age system  had  become  overtaxed  by  the  extra  areas  that  had  been  made  tributary  to 
it,  the  question  of  the  disposal  of  the  sewage  of  the  higher  districts  of  the  Metropolitan 
areas  tributary  thereto  was  the  subject  of  careful  investigation  in  1899  and  1900,  and 
it  was  decided  to  select  a  separate  outlet  for  the  high  level  sewer  in  a  portion  of  the 
harbor  where  strong  currents  were  available,  unaffected  by  sewage  from  the  other  main 
outlets. 

The  high-level  sewer  was  completed  and  first  operated  in  1904,  and  the  sewage 
which  it  receives  was  formerly  discharged  at  Moon  Island. 


Effect  of  the  Discharge  of  Sewage  at  Moon  Island 

The  quantity  of  sewage  discharged  at  the  various  main  sewer  outlets  in  Boston 
harbor  and  the  population  connected  with  each  is  shown  approximately  in  the  fol- 
lowing table: 


Boston  main  drainage  system 
North  Metropolitan  system. . 
South  Metropolitan  system . . 

Total  


Estimated 
Population, 
1908 


400,000 
500,000 
340,000 


1,240,000 


Quantity  of  Sewage  Discharged, 
Gallons  per  Day 


1907 


91,000,000 
60,000,000 
40,000,000 


191,000,000 


1912 


55,700,000 
48,200,000 


103,900,000 


The  quantity  of  sewage  discharged  at  Moon  Island  is  now  about  three  times  as 
great  as  the  quantity  discharged  in  the  first  year  after  the  completion  of  the  works, 
when  the  amount  was  about  30,000,000  gallons  per  day  on  an  average,  though  in  dry 
weather  the  flow  was  less  than  that  amount  and  in  wet  weather  was  sometimes  more 
than  twice  the  average  quantity.  The  daily  quantity  of  sewage  discharged  at  Moon 
Island  amounted  to  over  60,000,000  gallons  in  1891  and  rose  to  over  100,000,000  gal- 
lons shortly  before  the  completion  of  the  high-level  sewer. 

The  quantity  of  sewage  discharged  at  the  Deer  Island  outlet  in  1899 — five  years 
after  the  completion  of  the  works — amounted  to  about  48,000,000  gallons.  The  quan- 
tity discharged  at  the  high-level  sewer  outlet  in  1905 — the  first  year  after  its  comple- 
tion—amounted to  25,000,000  gallons  per  day  and  in  1906  to  33,000,000  gallons. 

The  first  observations  of  the  results  of  the  discharge  of  sewage  at  Moon  Island 
were  made  by  the  engineer  in  charge  of  the  main  drainage  works  about  15  months 
after  the  operation  of  the  system  was  begun.  At  that  time  the  sewage  was  stored  for 
about  10  hours  and  the  discharge  was  begun  about  1  hour  after  the  beginning  of  the 
ebb  tide.  At  this  time  the  surface  of  the  sea  was  as  low  as  the  bottom  of  the  reser- 
voir and  a  good  harbor  current  was  setting  outward  past  the  outlet.  A  description  of 
those  observations  is  as  follows: 

The  first  sewage  which  discharges  at  the  outlet  contains  a  considerable 
amount  of  sludge  which  has  settled  in  the  gallery  and  discharge  sewers,  and  gives 
to  the  effluent  a  dark,  muddy  appearance.  After  a  few  minutes  the  color  is  some- 
what lost,  and  the  effluent  looks  like  moderately  dirty  water. 


REPORT  OF  X.  H.  GOODNOUGH 


333 


Its  effect  in  discoloring  the  salt  water,  and  its  course  as  it  joins  the  current 
out  of  the  harbor,  can  be  plainly  noticed.  Being  fresh  water  it  rises  to  the  sur- 
face, and  when  a  half-mile  from  the  outlet  seems  to  lie  on  top  of  the  salt  water 
in  a  stratum  but  a  few  inches  thick.  The  greasy  nature  of  the  sewage  tends  to 
quiet  the  ripples  commonly  seen  on  the  surface  of  the  harbor,  so  that  the  area 
affected  by  the  discharge  is  plainly  determined.  From  experiments  with  floats  it 
is  known  that  the  sewage  travels  nearly  five  miles,  following  the  Western  Way 
and  Black-Rock  Channel  out  to  the  vicinity  of  the  Brewster  Islands.  By  the  time 
it  has  traveled  a  mile  from  the  outlet  most  of  the  color  is  lost,  and  by  the  time  it 
has  gone  two  miles  (before  passing  Rainsford  Island)  not  the  slightest  trace  of  it 
can  be  distinguished. 

The  only  objectionable  condition  found  on  the  shores  about  the  outlet  appears  to 
have  been  in  a  small  cove  or  angle  between  the  pier  containing  the  discharge  sewers 
and  the  shore  of  the  island,  where  sludge  from  the  sewage  deposited  and  gave  off  an  ob- 
jectional  odor  at  times  of  low  tide. 

The  storage  reservoirs  were  enlarged  in  1889-1900,  however,  and  a  sea  wall  was 
built  across  the  end  of  the  island,  running  from  northeast  to  southwest,  and  the  out- 
let is  now  located  at  the  northeasterly  end  of  the  wall.  There  is  a  small  area  exposed 
at  low  tide  along  the  foot  of  this  wall,  on  which  sludge  accumulates  in  the  summer 
season,  which  will  be  referred  to  later. 

The  conditions  about  the  Moon  Island  outlet  were  studied  soon  afterward  (1888) 
by  the  State  Board  of  Health,  in  connection  with  the  proposed  new  sewer  outlet  for 
the  North  Metropolitan  district,  and  a  test  was  made  of  the  discharge  of  sewage  con- 
tinuously at  Moon  Island  at  a  rate  of  about  36,000,000  gallons  per  day,  with  a  view  to 
determining  what  effect  the  discharge  would  be  likely  to  have  at  Deer  Island.  The 
results  of  these  observations  are  summarized  in  the  report  of  the  Board  as  follows : 

At  the  Moon  Island  outlet  of  the  Boston  Main  Drainage  System  the  sewage 
collected  in  eleven  hours  is  generally  discharged  in  a  body  in  about  half  an  hour, 
and  no  sewage  is  to  be  found  in  the  tidal  current  into  which  it  enters  two  hours 
after  it  leaves  the  sewer.  That  we  might  make  observations  and  reach  just  con- 
clusions in  regard  to  a  stream  of  sewage  discharging  continuously,  the  officers  in 
charge  of  the  Boston  Main  Drainage  Works  kindly  cooperated  with  the  Board  by 
discharging  continuously,  on  a  falling  tide,  for  four  hours,  about  1,500,000  gal- 
lons per  hour,  the  equivalent  of  36,000,000  gallons  per  day,  which  is  the  amount 
estimated  to  be  discharged  at  Deer  Island  outlet  when  the  population  is  between 
300,000  and  400,000. 

When  sailing  in  the  stream  of  sewage,  or  on  the  leeward  side  of  it,  from  near 
the  outlet  of  the  sewer  and  for  a  distance  of  half  a  mile  along  the  stream,  the 
odor  of  the  sewage  was  disagreeable.  Continuing  in  the  stream  of  sewage  beyond 
this  distance,  the  odor  was  noticeable  for  a  time,  but  before  reaching  the  distance 
of  three-quarters  of  a  mile  from  the  outlet  of  the  sewer  the  odor  could  not  be  dis- 
tinguished. At  this  distance,  however,  the  color  of  the  water  was  distinctly  dif- 
ferent from  the  blue  of  sea  water — it  was  more  opaque  and  browner.  But  there 
was  nothing,  at  this  distance,  with  wind  blowing  up  stream  toward  the  outlet  of 
sewer,  either  in  appearance  or  odor,  that  was  in  the  least  objectionable.  The  ap- 
pearance of  the  water  here  was  like  that  in  the  upper  harbor  in  midstream,  be- 
tween the  Cunard  wharf  and  the  New  York  and  New  England  railroad  docks. 
By  the  color  and  stillness  of  the  surface  the  area  containing  sewage  could  be 


334 


REPORTS  OF  EXPERTS 


distinguished  for  a  quarter  of  a  mile  farther,  or  at  a  distance  of  one  mile  from  the 
outlet;  but  no  odor  could  be  distinguished,  and  there  was  no  disagreeable 
appearance. 

At  one  mile  and  a  quarter  a  narrow  strip  of  smooth  water  and  a  slightly 
opaque  character  of  the  water — seen  only  upon  very  careful  examination — indi- 
cated an  effect  from  sewage;  but  at  one  and  a  half  miles  from  the  outlet  no 
trace  of  the  sewage  could  be  seen,  although  floats  which  started  with  the  sewage 
had  gone  far  beyond. 

To  present  this  subject  with  more  definiteness  than  can  be  conveyed  by  re- 
cording the  observations  of  individuals,  samples  of  the  water  taken  from  the 
middle  of  the  stream  of  sewage  were  subjected  to  more  careful  chemical  tests,  in 
comparison  with  the  adjacent  salt  water  which  was  unaffected  by  this  sewage, 
and  with  the  salt  water  of  the  inner  harbor. 

Samples  of  the  sewage  throughout  the  stream  of  observable  sewage  and  be- 
yond were  taken  within  eight  inches  of  the  surface,  after  the  stream  had  flowed 
in  nearly  the  same  place  for  three  hours,  and  were  subjected  to  chemical  analysis 
with  the  following  results : 


TABLE  XLVI 


Free 
Ammonia 

Albuminoid 
Ammonia 

Sum  of 
Ammonias 

Chlorine 

Salt  water,  up  stream,  from  area  containing  sewage  

.0056 

.0098 

.0154 

1,675 

Salt  water,  down  stream,  from  area  containing  sewage  

.0056 

.0095 

.0151 

1,746 

Water,  within  area  containing  sewage,  at  the  following  dis- 

tances from  outlet: 

400  feet  

2.5000 

.5310 

3.0310 

773 

1,600  "   

.1944 

.0636 

.2580 

1,570 

3,200  ■   

.0416 

.0264 

.0670 

1,621 

4,700  "   

.0224 

.0116 

.0340 

1,694 

6,200  "   

.0184 

.0156 

.0340 

1,689 

7,200  "   

.0136 

.0108 

.0244 

1,687 

9,200  "   

.0104 

.0096 

.0200 

1,710 

Water  in  mid  stream  at  crossing  of  North  ferry  to  East 

.0480 

.0154 

.0634 

1,581 

From  these  analyses  it  appears  that  in  the  stream  of  sewage  at  four  hundred 
feet  from  the  outlet  of  the  sewer  the  upper  eight  inches  in  depth  was  about  one- 
half  sewage.  At  1,600  feet  distant  it  contained  about  one-eighteenth  of  its  bulk 
of  sewage,  and  at  3,200  feet,  or  five-eighths  of  a  mile  distant  from  the  outlet  of 
the  sewer,  the  ammonias  indicated  the  amount  of  sewage  added  to  be  but  1  per 
cent,  of  the  volume  of  the  water,  and  the  same  amount  as  found  in  midstream  at 
the  crossing  of  North  Ferry  to  East  Boston.  Beyond  this  distance  the  amount  of 
ammonia  added  became  about  one-half  of  1  per  cent,  at  a  mile,  and  less  than  one- 
tenth  of  1  per  cent,  at  one  and  four-fifth  miles  from  the  outlet. 

These  results  confirm  those  of  direct  observation.  With  the  ordinary  wave 
motion  at  this  place,  a  mile  from  the  outlet,  the  amount  of  sewage  remaining  near 
the  surface  of  the  water  is  so  small  that  no  disagreeable  appearance  or  odor  can 
be  recognized. 

Continued  observations  were  made  from  time  to  time  of  the  effect  of  the  dis- 
charge of  sewage  at  Moon  Island  in  subsequent  years,  and  a  very  thorough  study  was 
made  in  1899  by  the  Metropolitan  Sewerage  Commission,*  and  in  1900  by  the  State 
Board  of  Health.  Since  1902  the  outlets  have  been  examined  annually  by  the  State 
Board. 

♦Of  Boston. 


REPORT  OF  X.  H.  GOODNOUGH 


335 


Results  of  Numerous  Investigations  of  the  Effect  of  the  Discharge  of  Sewage 

at  the  Moon  Island  Outlet 

Sewage  is  discharged  from  the  reservoirs  at  the  Moon  Island  outlet  at  about  the 
level  of  the  sea,  with  a  strong  initial  velocity,  and  observations  show  that  the  sewage 
advances  over  the  surface  of  the  tidal  current  at  a  more  rapid  rate  than  the  flow  of 
the  current.  The  area  covered  varies  greatly,  being  greatest  on  calm  days,  when  it 
may  cover  an  area  of  nearly  1,000  acres.  Under  ordinary  conditions  the  area  covered 
is  smaller.  The  field  covered  by  the  discharge  is  plainly  marked  on  fairly  calm  days 
by  the  thin  film  of  grease  which  spreads  over  the  surface  of  the  water  and  which 
covers  a  considerably  wider  area  than  that  in  which  sewage  can  be  detected.  The 
presence  of  sewage  can  be  noted  by  the  suspended  matter  in  the  water  for  a  distance 
of  one  and  one-talf  miles  from  the  outlet,  but  areas  containing  small  quantities  of 
sewage  are  sometimes  found  at  greater  distances.  The  area  in  which  the  sewage  gives 
the  water  an  objectionable  appearance  is  about  one  square  mile  under  ordinary  con- 
ditions, but  the  objectionable  odors  due  to  the  sewage  are  confined  to  a  comparatively 
small  portion  of  this  area.  The  sewage  spreads  widely  upon  the  surface  of  the  water, 
covering  it  with  a  layer  of  sewage,  which  rapidly  grows  thinner  as  the  distance  from 
the  outlet  increases,  and  except  in  the  neighborhood  of  the  outlet  sewage  is  rarely 
detectable  in  samples  of  water  collected  5  feet  beneath  the  surface. 

After  the  discharge  has  ceased  the  sewage  disappears  quite  rapidly,  its  disap- 
pearance being  observable  by  the  change  in  the  color  of  the  water.  These  changes 
take  place  all  over  the  area  and  the  sewage  rapidly  breaks  up  into  small  fields  and 
occasionally  areas  containing  traces  of  sewage  can  be  seen  for  a  considerable  time 
after  the  general  sewage  tract  has  become  quite  thoroughly  broken  up.  Large  areas 
covered  by  sleek  or  the  thin  film  of  grease  sometimes  persist  for  a  longer  time  but 
frequently  do  not  contain  underneath  this  film  enough  sewage  to  be  detectable  in  the 
water. 

No  accurate  soundings  are  available  to  show  whether  there  has  been  a  shoaling 
of  the  water  around  the  Moon  Island  sewer  outlet.  The  sea  is  very  shallow  along  the 
sea  wall  southeast  of  the  outlet  and  at  this  point  a  deposit  of  sewage  sludge  occurs  in 
the  summer  season,  which  attains  a  depth  of  several  inches.  A  small  portion  of  this 
only  is  exposed  at  low  water,  so  that  it  does  not  cause  a  serious  nuisance.  This 
deposit  is  carried  away  by  the  heavy  northeasterly  storms  of  winter  and  the  bottom 
becomes  quite  clean  after  such  storms.  Boatmen  who  navigate  these  waters  state 
that  they  have  not  noticed  any  soaling  of  consequence  in  this  region  since  the  sewer 
outlet  was  first  established.  Soundings  across  the  channel  between  Moon  Island  and 
Long  Island  have  shown  the  presence  of  mud  on  .the  bottom  of  the  harbor  in  this  sec- 
tion and  no  doubt  heavier  portions  of  the  sewage  settle  here  before  final  decomposi- 
tion, but  there  is  no  available  record  of  the  character  of  this  bottom  before  the  dis- 
charge of  sewage  was  begun.  Considering  the  enormous  quantity  of  sewage  matter 
that  has  been  discharged  here  in  the  25  years  since  the  outlet  was  first  used,  it  is 
evident  that  whatever  accumulations  may  have  taken  place  have  been  inconsiderable 
and  that  the  shoaling,  if  any,  takes  place  so  slowly  that  it  is  of  little  practical  con- 
sequence. 

Effect  of  the  Discharge  of  Sewage  at  Deer  Island 

The  main  outlet  for  the  North  Metropolitan  system  of  sewers  at  Deer  Island  is 
located  in  the  neighborhood  of  Deer  Island  Light  at  the  end  of  a  long  sand  bar  which 


336 


REPORTS  OF  EXPERTS 


is  uncovered  at  low  tide.  The  outlet  is  placed  at  the  level  of  low  water  or  a  little  below 
it,  so  that  it  is  covered  with  water  at  all  times  and  at  high  tide  to  a  depth  of  about  10 
feet.  The  tidal  current  at  this  outlet  reaches  a  velocity  of  4  miles  an  hour,  or  about 
6  feet  per  second. 

Studies  of  the  discharge  of  sewage  at  this  outlet  have  shown  that  with  a  flow  of 
about  2,000,000  to  3,000,000  gallons  per  hour  the  area  covered  by  sewage  on  the  ebb 
tide  is  about  1*4  miles  in  length  and  about  two  -fifths  of  a  mile  in  width  at  the  widest 
place,  and  the  area  aggregates  about  250  acres  under  average  conditions.  On  the  in- 
coming tide  sewage  flows  in  the  direction  of  Governor's  Island  and  on  still  days 
covers  a  slightly  larger  area  than  on  the  ebb. 

Observations  of  the  number  of  bacteria  in  the  water  show  that  they  diminish 
with  great  rapidity  as  the  distance  from  the  outlet  increases,  and  the  number  found 
at  a  distance  of  a  mile  from  the  outlet  is  about  300  per  cubic  centimeter.  Three 
thousand  feet  from  the  outlet  the  bacteria  in  the  sewage  amounted  on  one  occasion 
to  about  1,800  per  cubic  centimeter. 

The  depth  of  sewage  in  the  water  immediately  about  the  outlet  reaches  5  feet 
and  the  sea  water  in  the  neighborhod  of  this  outlet  where  sewage  is  densest  had  been 
found  on  one  examination  to  contain  about  3  per  cent,  of  sewage.  Traces  of  sewage 
in  this  case  also  were  largely  confined  to  the  surface  of  the  sea  and  little  trace  of  it 
could  be  found  at  a  depth  of  a  few  feet  except  in  the  immediate  neighborhood  of  the 
outfall.  The  odor  about  this  outlet  is  much  less  noticeable  than  in  the  neighborhood 
of  the  Moon  Island  outlet,  partly,  no  doubt,  because  the  sewage  discharged  here 
is  fresher  and  partly  because  the  quantity  of  sewage  discharged  at  one  time  rarely 
exceeds  3,000,000  gallons  per  hour,  while  the  quantity  discharged  at  Moon  Island 
amounts  to  an  average  of  20,000,000  per  hour  for  periods  of  two  hours  twice  each  day. 

The  Outlet  op  the  High-Level  Sewer  at  Peddock's  Island 

The  sewage  from  the  high-level  sewer,  so  called,  is  discharged  at  two  points — one 
located  off  the  northwesterly  shore  of  Peddock's  Island,  one  mile  north  of  Nut  Island, 
and  the  other  1,500  feet  to  the  east  and  nearer  Peddock's  Island.  The  outlets  are 
located  in  the  strong  current  of  President  Roads,  which,  during  the  incoming  tide, 
flows  around  the  southerly  end  of  Peddock's  Island  into  Hingham  Bay,  and  during 
the  outgoing  tide  flows  through  President  Roads  to  the  sea.  The  outlets  were  separ- 
ated because  observations  of  the  discharge  of  sewage  at  the  other  outlets  had  shown 
that  sewage,  when  discharged  continuously  into  a  strong  tidal  current,  tended  to  flow 
in  rather  a  narrow  field  and  for  a  comparatively  short  distance,  and  it  was  expected 
that  by  dividing  the  flow  the  sewage  would  become  more  quickly  diluted  when  mingled 
with  the  large  volume  of  water  flowing  through  this  seaway,  and  would  be  carried  to 
sea  before  it  could  create  a  nuisance  or  lodge  upon  any  inhabited  shore  or  at  a  place 
where  it  might  be  objectionable.  It  is  expected  in  the  future  that  a  much  larger 
quantity  of  sewage  will  be  discharged  at  this  outlet  than  is  the  case  at  the  present 
time,  but  the  amount  now  discharged  has  so  little  effect  upon  the  water  into  which  it 
flows  that  even  when  the  discharge  is  much  larger  than  the  average  the  sewage  can 
be  seen  only  in  a  very  small  field.  It  has  not  been  necessary  to  use  both  outlets  at  the 
same  time  and  all  of  the  sewage  has  thus  far  been  discharged  through  one  outlet,  but 
the  outlets  are  used  alternately  for  periods  of  several  weeks  to  keep  them  free  of 
deposits. 


REPORT  OF  X.  H.  GOODNOUGH 


337 


The  Peddock's  Island  outlets,  in  contrast  to  those  previously  described,  are  located 
in  a  deep  tidal  channel,  and  the  depth  of  water  over  the  outlets  is  30  feet  at  mean  low 
tide  and  40  feet  at  high  tide.  The  sewage  rises  rapidly  through  the  salt  water  but  is 
evidently  greatly  dispersed  and  diluted  before  reaching  the  surface  of  the  sea  and  is 
nowhere  as  dense  at  the  surface  of  the  water  as  is  the  case  at  Moon  Island  or  even  at 
the  Deer  Island  outlet.  Not  only  is  the  density  much  less  and  the  sewage  already  ap- 
parently greatly  diluted  when  reaching  the  surface  of  the  sea,  but  it  also  spreads  for 
a  much  more  limited  distance.  Very  little  odor  of  sewage  can  be  detected  about  this 
outlet,  excepting  in  its  immediate  neighborhood,  even  when  discharging  sewage  at 
the  rate  of  2,500,000  gallons  per  hour. 

Comparing  the  various  observations  that  have  thus  far  been  made  of  the  dis- 
charge of  sewage  at  the  various  outlets,  it  is  evident  that  the  sewage  discharged  at 
the  Peddock's  Island  outlets  disperses  much  more  rapidly  than  at  the  Deer  Island 
outlet  and  is  noticeable  over  a  much  smaller  field.  On  very  calm  days  the  sleek  from 
this  outlet  sometimes  covers  a  considerable  area.  The  sleek,  however,  is  a  very  thin 
film  of  grease  or  oil,  often  noticeable  upon  the  surface  of  the  water  after  all  of  the 
sewage  has  been  dispersed. 

Summary  op  the  Results  of  the  Discharge  of  Sewage  at  the  Three  Principal 

Outlets  in  Boston  Harbor 

The  conditions  affecting  the  discharge  of  sewage  at  the  three  main  outlets  in 
Boston  harbor  differ  widely  in  the  quantity  of  sewage  discharged,  the  strength  of 
the  currents,  the  location  of  the  outfalls  and,  to  some  extent,  in  the  character  of  the 
sewage.  The  sewage  discharged  at  the  Moon  Island  outlet  passes  on  its  way  from 
the  city  through  deposit  sewers  or  settling  tanks  for  the  removal  of  sand,  subse- 
quently through  a  long  tunnel  under  Dorchester  Bay  and  is  then  stored  for  several 
hours  in  open  reservoirs  on  Moon  Island  before  being  discharged.  The  sewage  dis- 
charged from  the  North  Metropolitan  district  at  Deer  Island  contains  a  large  pro- 
portion of  very  foul  manufacturing  wastes,  including  wastes  from  slaughter  houses, 
pork  packing  establishments,  tanneries,  currying  shops,  etc.,  and  much  of  it  is 
pumped  twice  and  a  large  portion  of  it  three  times  before  reaching  the  outlet.  It  is 
not  passed  through  settling  tanks  or  stored  in  reservoirs  at  any  point,  however,  and 
reaches  the  outlet  in  a  much  fresher  state  than  the  sewage  discharged  at  Moon 
Island.  Part  of  the  sewage  discharged  at  Peddock's  Island  from  the  high-level  sewer 
flows  there  by  gravity,  while  a  little  over  half  of  it  is  pumped  into  that  sewer  from 
the  main  sewer  of  the  Charles  River  valley  and  this  sewage  is  probably  as  fresh  when 
it  reaches  the  outlet  as  that  discharged  at  Deer  Island  and  is  less  affected  by 
pumping. 

The  discharge  at  Moon  Island  occupies  only  about  two  hours  on  each  tide,  so 
that  with  the  present  quantity  of  sewage  the  sewage  flows  into  the  sea  at  a  rate  of 
20.000,000  to  25,000,000  gallons  per  hour.  The  sewage  is  discharged  at  the  surface 
of  the  sea  with  quite  a  rapid  velocity,  so  that  it  tends  to  spread  widely  over  the  sur- 
face and  doubtless  covers  a  larger  area  than  it  would  if  the  outlet  were  located  in  a 
considerable  depth  of  water.  At  Deer  Island  sewage  is  discharged  somewhat  below 
the  level  of  low  water  and  this  condition  evidently  offers  a  better  opportunity  for 
dilution  than  is  the  case  at  Moon  Island.  At  Peddock's  Island,  where  the  outlets 
are  30  feet  below  the  level  of  low  tide,  it  is  very  evident  from  inspection  that  the 
sewage  has  become  very  considerably  diluted  before  reaching  the  surface  of  the  sea. 


338 


REPORTS  OF  EXPERTS 


The  current  into  which  the  sewage  is  discharged  at  Moon  Island  at  its  maximum 
is  less  than  2  miles  an  hour  and  is  usually  not  much  over  1  mile  per  hour.  At  Deer 
Island  the  maximum  current  is  4  miles  per  hour,  and  a  nearly  equal  maximum  is 
reached  at  Peddock's  Island. 

The  spread  of  the  sewage  at  Moon  Island  over  a  wide  area  is  evidently  prin- 
cipally due  to  the  greater  quantity  discharged  there,  as  compared,  with  the  other  two 
outlets,  to  the  manner  of  discharge  and  to  the  slackness  of  the  currents. 

The  sewer  outlets  in  Boston  harbor  in  all  cases  discharge  into  tidal  currents  of 
a  volume  many  times  greater  than  the  amount  of  sewage  which  they  now  receive. 
Careful  analyses  of  the  water  over  the  field  covered  by  sewage  at  Moon  Island  show 
little  trace  of  it  within  a  few  hours  after  the  discharge  ceases,  notwithstanding  the 
fact  that  this  outlet  has  been  in  operation  for  many  years.  Similarly  at  Deer  Island 
no  deposits  of  sewage  are  traceable  along  the  shores  about  the  outlet  nor  is  it  possible 
to  detect  even  by  chemical  analysis  any  effect  of  the  sewage  on  the  sea  water  except 
in  the  immediate  field  in  which  it  flows. 

All  things  considered,  the  Peddock's  Island  outlet,  judging  from  the  experience 
up  to  the  present  time,  will  probably  be  the  most  satisfactory  of  those  now  in  use. 
The  chief  advantage  at  this  outlet  over  the  outlet  at  Deer  Island  appears  to  be  due 
to  the  fact  that  it  is  located  in  deep  water  and  that  the  sewage  becomes  considerably 
diluted  before  it  appears  at  the  surface.  The  volume  of  the  tidal  currents  at  Deer 
Island  and  Peddock's  Island  are  much  greater  than  at  Moon  Island,  but  at  the  latter 
point  the  volume  of  the  current  is  very  large  in  proportion  to  the  quantity  of  sewage, 
amounting  on  the  ebb  between  Long  and  Rainsford  islands  to  more  than  70,000  cubic 
feet  per  second. 

General  Effects  of  the  Discharge  of  Sewage  at  the  Various  Outlets 

The  reservoirs  in  which  the  sewage  is  stored  at  Moon  Island  are  uncovered  and 
odors  from  them  are  noticeable  at  times  for  a  considerable  distance  under  conditions 
favorable  for  their  dissemination.  They  are  not  serious  enough  to  make  it  desirable 
to  cover  the  reservoirs.  As  stated  above,  an  offensive  odor  is  noticeable  when  sailing 
in  the  field  of  sewage  within  half  a  mile  to  a  mile  from  the  outlet  for  a  time  after  the 
discharge  has  taken  place,  but  within  a  very  short  time  after  the  discharge  ceases  the 
sewage  disappears,  and  chemical  analyses  have  shown  that  very  little  effect  of  the  sew- 
age is  traceable  in  the  water  after  the  effect  of  the  discharge  has  disappeared  from  sight. 

At  the  Deer  Island  outlet,  where  the  sewage  covers  a  smaller  area,  the  odors  are 
noticeable  only  when  sailing  within  a  few  hundred  feet  of  the  outlet. 

At  Peddock's  Island  an  odor  of  sewage  is  noticeable  only  immediately  about  the 
outlet  itself. 

The  results  of  careful  examinations  of  the  shores  of  the  harbor  and  of  the  islands 
therein  show  no  visible  trace  of  the  discharge  of  sewage  excepting  the  grease  balls  which 
form  in  the  sewers  and  when  discharged  float  upon  the  water,  and  may  be  carried  by 
the  currents  for  many  miles  before  they  become  thoroughly  broken  up. 

The  results  of  observations  upon  the  effect  of  the  discharge  of  sewage  at  the  vari- 
ous outlets  in  Boston  harbor  as  herein  given  are  based  upon  the  conditions  found  in 
comparatively  calm  weather  in  the  warmer  portion  of  the  year.  In  storms  and  at 
times  of  high  winds  the  effect  of  the  sewage  is  much  less  noticeable  than  at  other  times. 

Respectfully  submitted, 

June  11,  1909.  X.  H.  Goodnough. 


PART  IV 

Data  Relating  to  the  Protection  of  the  Harbor 


PART  IV 


Data  Relating  to  the  Protection  of  the  Harbor 

CHAPTER  I 

THE  UTILIZATION  OF  SEWAGE  WITH  SPECIAL  REFERENCE  TO  THE 
POSSIBILITY  OF  DERIVING  A  FINANCIAL  RETURN 
FROM  THE  SEWAGE  OF  NEW  YORK  CITY 

The  utilization  of  sewage  is  so  desirable,  yet  so  little  practised,  that  the  Commis- 
sion has  made  an  inquiry  into  the  subject  with  the  object  of  bringing  together  the 
most  important  data  in  regard  to  it. 

The  opinion  which  the  Commission  has  drawn  from  this  study  is  that,  although 
the  present  state  of  science  does  not  warrant  New  York  in  seeking  to  turn  its  sewage 
to  profitable  account,  some  process  may  be  discovered  whereby  this  end  can  be  accom- 
plished. The  most  helpful  direction  in  which  to  look  for  this  result  is  with  the  sludge. 
The  works  which  the  Commission  recommends  are  intended  to  dispose  of  the  sewage 
without  immediate  regard  to  profit,  but  they  are  so  designed  as  to  provide  for  utiliza- 
tion in  case  suitable  processes  for  the  accomplishment  of  this  end  are  ever  devised. 

The  term  profit  is  here  used  in  the  customary  sense  to  mean  a  return  in  money, 
or  its  equivalent,  which  may  be  applied  to  reduce  the  cost  of  building  and  operating 
such  works  as  may  be  necessary  to  dispose  of  the  sewage  in  a  sanitary  manner.  If  by 
profit  is  meant  such  a  saving  in  the  cost  of  purification  as  can  be  effected  by  a 
proper  employment  of  the  forces  of  nature  to  absorb  and  carry  off  the  objectionable 
materials,  the  case  is  different.  In  this  sense  the  most  profitable  use  of  New  York's 
sewage  is  that  which  nature  provides  in  the  digestive  capacity  of  the  harbor  water, 
whereby  a  large  part  of  the  offensive  and  harmful  ingredients  of  sewage  are  ren- 
dered harmless  without  cost.  There  is  here  a  valuable  asset  which,  if  it  does  not  pro- 
duce visible  return,  is  none  the  less  capable  of  effecting  an  immense  saving  to  the  city 
over  the  cost  of  works  whose  object  it  is  to  purify  the  sewage. 

COMPOSITION  OF  SEWAGE  WITH  REFERENCE  TO  UTILIZATION 

It  has  been  impracticable  to  analyze  the  sewage  produced  throughout  New  York 
City  and  it  has  never  appeared  to  the  Commission  desirable  to  do  so.  The  sewage 
is  contributed  by  the  houses  and  streets  through  a  large  number  of  local  sewerage 
systems,  most  of  which  discharge  through  outlets  which  are  submerged  at  most 
stages  of  the  tide.  During  all  stages,  the  water  of  the  harbor  backs  up  into  the  sewers, 
thereby  materially  affecting  the  quality  of  the  sewage.  The  effect  produced  is  com- 
plicated.   The  sewage  is  not  only  diluted,  but  changes  are  produced  in  its  composi- 


342         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

tion  by  reason  of  the  salty  condition  of  the  harbor  water.  Owing  to  the  interference 
produced  in  the  flow  of  sewage,  deposits  occur  and  an  opportunity  is  afforded  for 
decomposition  to  take  place. 

The  distance  from  the  water  front  to  which  the  effects  of  the  tide  may  produce 
decided  alterations  in  sewage  varies  with  the  part  of  the  city  under  consideration.  In 
some  parts  of  Manhattan  and  the  Bronx,  the  sewers  feel  the  effects  of  the  tides  in  the 
harbor  for  over  a  mile  from  the  sewer  outlets.  It  would  be  impossible  to  collect 
samples  of  sewage  near  the  outlets  at  any  stage  of  tide  which  would  show  the  average 
composition  of  the  sewage  through  the  twenty-four  hours,  and  samples  taken  at  any 
other  point  could  not  be  considered  as  representative  of  the  sewage  with  which  main 
drainage  works  would  have  to  deal. 

The  standard  sewage  assumed  by  the  Commission  is  based  upon  the  known  com- 
position of  the  sewage  of  such  other  cities  as  afford  reliable  data  on  the  composition 
of  their  sewage  and  in  which  the  conditions  of  residence  and  manufacture  are  more 
or  less  similar.  It  is  not  expected  that  the  standard  sewage  assumed  will  actually  be 
met  with  when  main  drainage  works  are  constructed,  but  the  basis  of  this  standard 
sewage  being  stated,  it  will  be  easy  to  make  such  changes  as  may  be  necessary  in  the 
main  drainage  works  in  order  that  they  may  meet  the  requirements  of  sewage  which 
varies  from  the  standard  in  any  important  particular. 

Origin  and  Variable  Quality  of  the  Mixture.  The  sewage  from  the  average 
American  city,  when  fresh,  possesses  a  dirty  gray  color  and  gives  off  a  slightly  un- 
pleasant and  rather  musty  odor.  A  large  sample  is  likely  to  contain  small  pieces  of 
newspaper  and  toilet  paper  and  fine  particles  of  suspended  matter.  Most  of  the  par- 
ticles will  pass  through  a  screen  with  a  mesh  of  one-eighth  of  an  inch,  the  largest 
particles  at  the  surface  of  the  sewage  being  excluded.  The  small  solid  particles  are 
composed  partly  of  fecal  matter  and  paper  broken  up  by  friction  against  the  walls 
of  the  sewers,  but  there  are  many  minute  pieces  of  fiber,  cloth  and  other  material, 
obviously  of  human  origin,  and  a  considerable  amount  of  mineral  detritus. 

It  has  frequently  been  remarked  that  the  presence  of  human  excrement  produces 
very  little  effect  upon  either  the  composition  or  appearance  of  sewage.  Excrement  is 
especially  noticeable  when  sewers  are  short.  Few  of  the  sewers  of  Manhattan  are 
long  and  an  unusually  large  amount  of  solid  particles  separately  recognizable  as  of 
human  origin  reach  the  outlets. 

Upon  standing,  many  of  the  solid  particles  of  sewage  settle  out,  causing  a  dirty, 
dark  and  somewhat  slimy  deposit  called  sludge. 

If  sewage  is  allowed  to  stand  for  a  few  hours  at  ordinary  summer  temperature, 
it  becomes  putrid  and  this  is  true  whether  the  suspended  matter  has  been  removed  or 


UTILIZATION  OF  SEWAGE  343 

not.  If  greatly  diluted  with  water  or  put  upon  a  sufficient  area  of  land,  it  will  not 
putrefy;  in  either  case,  the  organic  substances  are  gradually  converted  into  harmless 
and  inoffensive  compounds.  It  is  when  the  natural  purifying  agencies  which  are 
present  in  soil  and  water  are  overtaxed  that  putrefaction  with  its  offensive  odors  is 
produced.  All  methods  of  purifying  sewage  artificially  aim  to  resolve  the  substances 
which  are  capable  of  putrefaction  into  stable  compounds  under  conditions  which  are 
under  control. 

The  IAquid  Portion.  The  liquid  portion  of  sewage  consists  not  only  of  water, 
but  of  a  large  number  of  substances  which  are  present  in  dissolved  and  diluted  form. 
The  most  prominent  component  of  the  liquid  part  of  sewage  is  urine  and  this,  in  com- 
bined sewers,  may  have  been  derived  not  only  from  the  human  population,  but  from 
animals,  particularly  horses,  upon  the  streets  and  in  stables.  As  appears  elsewhere 
in  this  report,  the  urine  contains  more  of  the  solid  matters  excreted  by  human  beings 
in  the  course  of  a  given  interval  of  time  than  do  the  feces. 

A  part  of  the  liquid  matter  of  sewage  consists  of  extractives  of  decomposable 
and,  in  some  cases,  decomposing  organic  matters  from  kitchens,  streets  and  factories. 
Some  of  these  extractives,  especially  those  of  industrial  origin,  may  present  diffi- 
culties of  peculiarly  troublesome  nature  in  the  final  disposition  of  the  sewage. 

In  the  artificial  purification  of  sewage,  it  is  customary  to  dispose  of  the  liquid  por- 
tion by  some  process  of  oxidation.  In  fact  this  material  cannot  be  finally  rendered 
inert  and  incapable  of  producing  offensive  odors  unless  it  is  oxidized. 

The  Solid  Ingredients.  Grit  constitutes  the  largest  part  of  the  solid  matter  con- 
tained in  combined  sewage,  if  weight  alone  is  considered.  It  is  derived  chiefly  from 
the  surface  of  the  streets  and  is  present  in  all  degrees  of  fineness  from  particles  of 
microscopic  proportions  to  sand  and  fine  gravel. 

By  the  solid  matters,  however,  is  usually  understood  the  relatively  large  mate- 
rials of  human  origin  which  make  sewage  offensive  to  the  senses.  In  the  report  of 
the  Commission  for  April  30,  1910,  the  solids  of  sewage  are  divided  into  three  classes : 
Those  which  sink  soon  after  the  sewage  is  discharged  into  the  harbor;  those  which 
continue  to  float  after  some  time  on  the  surface  of  the  water,  and  those  which  are  long 
carried  in  suspension  in  the  bodies  of  the  tidal  streams. 

It  is  evident  that  particles  do  not  always  remain  in  any  of  these  divisions.  Many 
of  those  which  float  gradually  become  broken  up  and  water-soaked  and  sink  beneath 
the  surface  of  the  water  and  thus  pass  from  the  second  to  the  first  division  or  to  the 
third.  In  the  third  class  are  the  colloids  or  semi-solid  materials  and  finely  divided 
particles  of  suspended  matters. 

In  disposing  of  sewage  by  artificial  methods,  the  management  of  those  solid  and 


344         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

semi-solid  matters  which  are  collectively  termed  sludge  is  recognized  as  of  paramount 
difficulty.  In  fact  the  disposal  of  sewage  resolves  itself,  in  the  average  case,  into  the 
separation  of  sludge  and  the  disposition  of  the  latter.  It  is  comparatively  easy  to  dis- 
pose of  the  liquid  part  of  sewage. 

The  Gases.  Contrary  to  popular  opinion,  there  is  no  gas  properly  termed  sewer 
gas.  Aside  from  the  very  large  amount  of  moisture  which  it  contains,  the  air  of  sewers 
does  not  differ  materially,  so  far  as  analyses  indicate,  from  outside  atmospheric  air. 
In  fact,  sewers  which  are  properly  ventilated  contain  such  a  large  amount  of  outside 
air  as  greatly  to  modify  the  composition  of  such  gases  as  may  be  attributable  to  the 
sewage. 

Probably  first  in  importance  among  the  gases  contained  or  produced  by  sewage 
is  marsh  gas,  CH4.  Marsh  gas  or  methane  is  produced  when  putrefaction  takes  place ; 
and  decomposition,  either  of  the  kind  termed  putrefaction  or  other,  is  invariably  present 
in  sewage.  Aside  from  the  fact  that  it  is  a  diluting  agent  which  is  capable  of  reducing 
the  amount  of  oxygen  present  by  mere  dilution,  marsh  gas  is  not  considered  objec- 
tionable in  sewer  air.  The  amount  present  is  very  small  in  sewers  which  are  well 
ventilated  and  so  constructed  as  to  avoid  deposits. 

The  decomposition  of  the  compounds  of  carbon,  of  which  the  organic  matter  of 
sewage  is  composed,  consumes  oxygen  and  gives  off  carbon  dioxide  as  do  the  human 
lungs.  The  amount  of  carbon  dioxide  present  in  sewer  air  and  in  sewage  is  small  and 
without  any  effect  upon  health.  It  is  also  without  odor.  The  offensive  odors  which 
arise  from  sewers  are  sometimes  due  to  ammonium  compounds,  sometimes  to  sulphur 
compounds  and  sometimes  to  mould  growths  on  the  sewer.  The  explosions  which 
occasionally  take  place  in  some  cities  are  generally  due  to  gasoline  fumes  or  illuminat- 
ing gas. 

Except  when  in  a  putrefying  condition,  there  is  usually  some  dissolved  oxygen  in 
sewage.  In  fact,  it  is  desirable  that  sewage  should  always  contain  this  gas  except 
where  it  is  liquefying  the  solid  organic  particles  in  order  to  facilitate  final  disposi- 
tion. If  sewers  are  well  ventilated  and  the  sewage  is  kept  fresh,  the  air  from  them 
will  not  be  objectionable. 

The  Mineral  and  Organic  Matters.  It  is  customary  to  report  the  analysis  of  sew- 
age as  containing  certain  amounts  of  solid  matters  present  in  the  mineral  and  in  the 
organic  state.  By  mineral  matters  is  meant  such  material  as  silica,  iron,  calcium  and 
other  materials  which  are  in  a  state  which  is  permanent  and  incapable  of  producing 
offense.  The  organic  matters  are  distinguished  from  the  mineral  substances  in  that 
they  can,  and  are  likely  to,  decompose.  With  the  mineral  matters,  the  art  of  sewage 
disposal  has  but  little  concern.    The  worst  effect  which  they  can  produce  is  to  con- 


UTILIZATION  OF  SEWAGE 


345 


tribute  to  the  formation  of  deposits  injurious  to  navigation  and  to  interfere  with 
processes  for  the  removal  of  the  organic  matters. 

The  term  organic  matter  is  generally  employed  in  a  loose  and  indefinite  manner. 
Strictly  speaking,  it  should  include  only  such  substances  as  contain  carbon  in  more 
or  less  loose  combination  with  other  chemical  elements.  Practically  organic  matter, 
as  determined  by  analyses,  often  means  such  ingredients  of  sewage  as  are  capable  of 
being  driven  off  by  ignition  at  red  or  white  heat  after  the  total  solid  materials  in 
sewage  have  been  extracted  by  evaporation,  although  it  is  quite  unreasonable  to  include 
as  organic  matter  of  sewage  such  volatile  mineral  matters  as  carbonates  and  salts  of 
ammonia.  It  is  misleading  to  reckon  with  the  decomposable  matters,  such  organic 
compounds  as  paper,  wood,  matches  and  hair.  These  substances,  except  in  com- 
minuted form,  are  not  likely  to  be  included  in  a  sewage  analysis  and  yet  it  must  be 
remembered  that  from  the  time  sewage  is  produced  to  its  final  disposition,  processes 
of  division  and  sub-division  are  continually  taking  place  among  the  solid  particles, 
so  that  it  is  impossible,  without  a  microscopic  examination,  to  distinguish  between 
the  resistant  and  non-resistant  parts  of  the  organic  content. 

The  Bacteria  and  Other  Forms  of  Life.  As  may  be  inferred  from  a  consideration 
of  the  origin  of  sewage,  bacteria  and  other  minute  forms  of  life  are  usually  present 
in  great  number  and  variety.  Those  of  essential  importance  comprise  the  infective 
agents  of  disease  and  the  bacteria  which  are  concerned  in  the  decomposition  of  the 
organic  matters.  So  far  as  utilizing  the  sewage  is  concerned,  the  bacteria  of  disease 
may  be  excluded  from  consideration  except  in  so  far  as  the  method  of  disposal  may 
lead  to  infection  as,  for  example,  through  drinking  water  supplies,  shellfish,  bathing, 
fishing,  the  collection  of  driftwood,  or  by  eating  the  raw  product  of  farms  on  which  sew- 
age or  sludge  has  been  used  as  a  fertilizer. 

No  process  of  sewage  purification,  except  disinfection  and  the  application  of  sew- 
age to  land,  has  thus  far  been  found  capable  of  eliminating  disease  germs.  Most 
processes  of  sewage  disposal  produce  but  little  effect  upon  the  dangerous  character  of 
the  sewage.  Sewage  purification  is  not  properly  to  be  regarded  as  a  sufficient  means 
of  protecting  sources  of  water  supply  into  which  the  sewage  must  eventually  be  dis- 
charged. The  necessary  protection  can,  in  most  cases,  be  much  more  suitably  and 
economically  effected  through  the  purification  of  the  drinking  water  than  by  the  puri- 
fication of  the  sewage.  This  does  not  mean  that  the  sewage  of  a  great  city  should  be 
discharged  into  a  natural  body  of  water  without  regard  to  the  harmful  bacteria  which 
may  be  present.  Where  disposal  entails  serious  risk  to  health,  special  precautions  in 
the  way  of  disinfection  should  be  practised. 

When  bacteria  which  are  capable  of  producing  disease  are  discharged  into  sewers, 
material  reduction  in  the  number  of  the  disease  germs  ordinarily  takes  place.  The 


346        DATA  RELATING  TO  THE  PROTECTION  OP  THE  HARBOR 

popular  belief  that  the  harmful  bacteria  multiply  in  sewage  and  in  polluted  water  is 
unfounded.  Laboratory  experiment  and  experience  gained  in  many  investigations 
show  that  there  is  little  danger  to  be  apprehended  by  those  who  may  be  compelled  to 
work  in  sewers  or  in  sewage  disposal  plants  because  of  the  germs  of  disease  which 
may  be  present. 

Where  sewage  is  discharged  into  natural  bodies  of  water  or  upon  land,  the  un- 
favorable conditions  which  there  occur  for  the  continued  life  of  the  bacteria  soon 
lead  to  the  elimination  of  all  danger.  Epidemics  of  typhoid  and  cholera  which  have 
been  traced  to  water  have  been  due,  in  most  cases,  to  relatively  recent  and  intense  pol- 
lution. Harmful  bacteria  appear  to  live  much  longer  in  sludge  than  in  the  liquid 
part  of  sewage. 

There  seems  to  be  no  special  risk  to  health  attending  any  of  the  processes  em- 
ployed in  the  utilization  of  sewage  except  where  gross  carelessness  exists.  Inquiries 
made  in  English  cities  where  the  conservancy  system  is  employed  have  failed  to  show 
that  the  employees  engaged  in  collecting  or  disposing  of  the  excrement  are  peculiarly 
prone  to  disease.  The  laborers  and  others  who  dwell  among  the  sewage  irrigation 
fields  of  Paris  and  Berlin  enjoy  excellent  health.  It  is  dangerous  to  sprinkle  fresh  sew- 
age upon  garden  vegetables  or  fruit  and  persons  who  work  with  sewage  should  be 
careful  to  cleanse  their  hands  thoroughly  before  eating. 

In  view  of  the  potential  danger  which  would  seem  to  exist  in  sewage,  it  is  remark- 
able that  so  few  epidemics  of  disease  have  been  attributed  to  the  disposal  of  sewage 
by  application  to  land.  Aside  from  a  few  explosions  of  typhoid  fever,  said  to  have 
been  produced  by  eating  celery,  lettuce  and  watercress,  there  is  little  recorded 
evidence  to  show  that  food,  other  than  milk  and  shellfish,  is  at  all  likely  to  become 
infected. 

The  destructive  agencies  which  cause  the  disappearance  of  harmful  bacteria, 
when  the  sewage  is  discharged  upon  land  or  into  a  natural  body  of  water,  are  not  all 
understood,  but  the  subject  has  been  investigated  sufficiently  to  show  that  sunlight, 
uncongenial  temperature  and  lack  of  suitable  food  are  among  the  principal  condi- 
tions which  make  for  the  destruction  of  pathogenic  bacteria.  So  particular  are  the 
requirements  of  disease  germs  that  there  are  very  few  known  species  which  will  live 
and  multiply,  except  for  a  brief  interval,  outside  of  the  body. 

Natural  Changes  Which  Sewage  Matters  Undergo  in  the  Presence  and  Absence  of 
Air.  Prominent  among  the  bacteria  which  must  be  considered  in  the  disposal  of  sew- 
age are  those  which  carry  on  the  various  forms  of  decomposition  to  which  sewage  is 


UTILIZATION  OF  SEWAGE  347 

liable.  The  bacteria  in  this  class  find  their  nutriment  in  the  dead  organic  matter  of 
sewage  as  distinguished  from  disease  germs  which  feed  upon  a  living  host. 

In  the  presence  of  a  sufficient  supply  of  oxygen,  the  bacteria  of  decomposition  are 
capable  of  breaking  up  the  complex  organic  molecules  of  the  solid  and  liquid  substances 
of  sewage  and  resolve  them  into  harmless  inert  mineral  matters.  Among  the  bacteria 
of  this  class  are  those  which  attack  the  ammoniacal  matters  and  produce  nitrates  and 
nitrites.  These  organisms  are  everywhere  present  in  soil  and  water.  They  are  indis- 
pensible  in  preventing  sewage  from  producing  offensive  odors. 

Septicization.  When  the  oxygen  supply  is  deficient  the  bacteria  of  putrefaction 
become  active  and  break  down  the  organic  compounds,  liquefying  the  solids  and  pro- 
ducing offensive-smelling  gases.  At  one  time  it  was  thought  desirable  to  utilize  putre- 
fying bacteria  in  order  to  get  rid  of  the  solid  organic  matters  and  otherwise  prepare 
the  sewage  for  final  disposal.  The  present  tendency  is  to  keep  the  sewage  from  putre- 
fying and  to  deal  with  it  in  the  freshest  condition  practicable.  In  the  average  case, 
no  useful  end  is  to  be  accomplished  by  bringing  about  septic  action,  as  putrefaction  is 
customarily  termed.  In  fact  unfavorable  conditions  due  to  foul  odors  brought  about 
by  septic  action  often  restrict  the  application  of  this  process. 

In  addition  to  the  bacteria,  other  forms  of  life  in  great  variety  are  present  in 
sewage.  Not  improbably  enzymes  and  other  ferments  are  intimately  connected  with 
the  phenomena  of  putrefaction  and  oxidation.  In  breaking  up  solid  particles,  larger 
forms  than  the  bacteria  are  of  use.  These  larger  forms  comprise  representatives  from 
the  animal  and  vegetable  kingdoms,  such  as  are  commonly  present  in  decomposing 
matters  of  any  kind.  The  black  color  of  septic  sewage  is  due  to  the  formation  of 
sulphide  of  iron  probably  by  bacterial  decomposition  of  sulphates. 

The  peculiar  musty,  sweetish  odor  noticeable  in  most  sewers  is  generally  ascribed 
to  fungus  growths.  Fungi  of  many  kinds  find  the  conditions  of  food,  temperature 
and  moisture  suited  to  them  in  sewers,  the  result  being  that  luxuriant  growths  often 
occur. 

Composition  of  the  Standard  Sewage  Assumed  for  Neiv  York.  The  composition  of 
New  York's  sewage  has  been  described  by  the  Commission  in  its  report  of  April  30, 
1910,  Chapter  X,  page  429,  report  of  August,  1912,  Chapter  III,  page  28,  and  prelimi- 
nary report  No.  VI,  February,  1913,  page  19. 

The  following  table  gives,  without  unnecessary  detail,  and  in  form  convenient  for 
use,  the  principal  ingredients  of  the  standard  sewage  of  the  City  of  New  York.  This 
composition  is  based  on  the  assumption  that  100  gallons  of  sewage  are  produced  per 
capita  per  24  hours. 


348 


DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


TABLE  XLVII 
Standard  New  York  Sewage 

Parts  by  Weight  per  Million 
of  Water 

Solid  Matters   800 

Dissolved   500 

Suspended   300 

Organic  and  Volatile  Matters   400 

Dissolved   200 

Suspended   200 

Nitrogenous   150 

Nitrogen   15 

Non-Nitrogenous   250 

Fat,  etc   50 

Total  Carbon   200 

Table  XLVIII,  prepared  from  Table  XLVII  and  data  contained  in  the  report  of 
this  Commission  dated  February,  1913,  pages  18  and  20,  gives  the  quantities  in  tons  of 
the  various  ingredients  of  the  sewage  calculated  in  accordance  with  the  foregoing  stand- 
ard composition,  the  number  of  gallons  per  capita  of  sewage  produced  and  the  popula- 
tion producing  the  sewage  as  of  the  years  1910  and  1940. 


TABLE  XLVIII 

Weight  op  Sewage  Ingredients  Tributary  to  the  Several  Divisions  op  the  Harbor. 
The  Results  Stated  Are  Tons  of  2000  lbs.  per  12  Lunar  Hours 


Division  of  the 
Harbor 


Harlem  river  

Hudson  river  

Upper  East  river . 
Lower  East  river . 

Upper  bay  

Newark  bay  

Kill  van  Kull  

Jamaica  bay  

Harlem  river  

Hudson  river  

Upper  East  river . 
Lower  East  river . 

Upper  bay  

Newark  bay  

Kill  van  Kull  

Jamaica  bay  


1910 


Sus- 

Organic and  Volatile  Matters 

pended 

Sewage 

Mgd. 
* 

Gallons, 

Solid 

Population 

per  Capita 

Matters 

Total 

Dis- 

Sus- 

Nitro- 

Fats, 

Car- 

per Day 

solved 

pended 

genous 

etc. 

bon 

52 

70 

35 

35 

26 

9 

35 

99 

797,000 

124 

65 

87 

43 

44 

33 

11 

43 

132 

1,900,000 

131 

12 

16 

8 

8 

6 

2 

8 

21 

182,000 

115 

133 

178 

89 

89 

67 

22 

89 

264 

2,058,000 

120 

34 

45 

23 

22 

17 

6 

23 

64 

519,000 

123 

7 

9 

4 

5 

3 

1 

4 

13 

103,000 

126 

3 

4 

2 

2 

2 

0.6 

2 

7 

50,000 

140 

23 

30 

15 

15 

11 

4 

15 

53 

351,000 

151 

1940 


111 

148 

74 

74 

56 

18 

74 

253 

1,708,000 

148 

126 

168 

84 

84 

63 

21 

84 

302 

1,940,000 

156 

43 

57 

29 

28 

21 

7 

29 

99 

649,000 

152 

209 

279 

139 

140 

105 

35 

139 

454 

3,223,000 

141 

59 

79 

40 

39 

30 

10 

40 

118 

908,000 

130 

13 

18 

9 

9 

7 

2 

9 

30 

200,000 

150 

9 

12 

6 

6 

4 

2 

6 

23 

139,000 
909,000 

165 

59 

79 

39 

40 

30 

10 

39 

163 

180 

*Million  gallons  per  day. 

The  Question  of  Utilization. — So  far  as  utilization  is  concerned,  the  most  valuable 
ingredients  of  sewage  are  nitrogen,  phosphoric  acid,  potash  and  fat.  The  following 
table  gives  the  amounts  of  these  substances,  excepting  the  fat,  found  in  the  sewage  of 


UTILIZATION  OF  SEWAGE 


349 


the  Lawrence,  Mass.,  Experiment  Station  during  1912,  as  stated  by  Mr.  H.  W.  Clark  in 
the  Monthly  Bulletin  of  the  State  Board  of  Health  for  December,  1913. 

TABLE  XLIX 

Amount  and  Value  of  the  Fertilizing  Constituents  in  100  Gallons  op  Lawrence 

Sewage 


Nitrogen  as  free  ammonia  

Kjeldahl  nitrogen  

Phosphoric  acid  reckoned  as  P2O2 
Potash  reckoned  as  K20  


Pound 

Cents  per 
Pound 

Value 
(Cents) 

.27 

16 

4.3 

.09 

10.0 

.9 

.08 

5.0 

.4 

.12 

4.2 

.5 

Each  thousand  gallons  also  contained  about  one-quarter  of  a  pound  of  fatty  mat- 
ters worth,  at  3  cents  per  pound,  about  7.5  mills. 

Assuming  that  the  composition  of  Lawrence  sewage  fairly  represented  the  sewage 
of  New  York,  the  following  table  has  been  prepared  to  show  the  weight  and  value  of  fer- 
tilizing ingredients  contained  in  the  sewage  which  is  tributary  to  the  several  divisions 
of  New  York  harbor.  The  Lawrence  sewage  contained,  in  parts  per  million,  the  follow- 
ing fertilizing  ingredients : 

Nitrogen  as  free  ammonia   32 

Kjeldahl  nitrogen   10 . 8 

P,0,   10.0 

K,0   15.0 

TABLE  L 

Weight  and  Value  of  Fertilizing  Ingredients  Contained  in  the  Sewage  Tributary 
to  the  Several  Divisions  of  New  York  Harbor 


Division  of  the 
Harbor 

Sewage 
Mgd. 

1910 

Quantities  in  Tons  of  2,000  Pounds  per 
24  Hours 

Values  per  24  Hours 

Nitrogen 
as  Free 
Ammonia 

Total 
Nitrogen 

P,0S 

K20 

Fats 

Nitrogen 
as  Free 
Ammonia 

Total 
Nitrogen 

P.O. 

K,0 

Fats 

Harlem  river  

Hudson  river  

Upper  East  river . 
Lower  East  river . 

Upper  bay  

Newark  bay  

Kill  van  Kull 
Jamaica  bay  

99 
132 

21 
246 

64 

13 
7 

53 

15.04 
20.05 
3.19 
37.35 
9.72 
1.98 
1.06 
8.05 

5.08 
6.78 
1.08 
12.62 
3.29 
0.67 
0.36 
2.72 

4.70 
6.27 
0.99 
11.68 
3.04 
0.62 
0.33 
2.51 

7.08 
9.43 
1.50 
17.56 
4.52 
0.93 
0.50 
3.79 

17.80 
23.73 
3.77 
44.20 
11.50 
2.34 
1.26 
9.52 

$4,812 
6,420 
1,020 
11,950 
3,110 
634 
339 
2,576 

$1,016 
1,355 
216 
2,525 
657 
134 
72 
544 

$470 
627 
99 
1,168 
304 
62 
33 
251 

$595 
792 
126 
1,475 
380 
78 
42 
318 

$1,068 
1,424 
226 
2,640 
690 
140 
76 
571 

Total  

635 

96.44 

32.60 

30.14 

45.31 

114.32 

$30,861 

$6,519 

$3,014 

$3,806 

$6,835 

Grand  Totals,  per  24  Hours:  Weight,  318.81  Tons;  Value,  $51,035. 

Per  Year:  Weight,  116,366  Tons;  Value, 
$18,627,775. 

350        DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

TABLE  L— Continued 


Division  of  the 
Harbor 

Sewage 
Mgd. 

1940* 

Quantities  in  Tons  of  2,000  Pounds  per 
24  Hours 

Values  per  24  Hours 

Nitrogen 
as  Free 
Ammonia 

Total 
Nitrogen 

Ps06 

K20 

Fats 

Nitrogen 
as  Free 
Ammonia 

Total 
Nitrogen 

P206 

KaO 

Fats 

Harlem  river  

Hudson  river  , 
Upper  East  river . 
Lower  East  river . 

Upper  bay  

Newark  bay  

Kill  van  Kull 
Jamaica  bay  

253 
302 
99 
454 
118 
30 
23 
163 

32.00 
38.22 
12.52 
57.45 
14.94 
3.80 
2.91 
20.62 

10.81 
12.90 
4.23 
19.40 
5.04 
1.28 
0.98 
6.96 

10.05 
12.00 
3.93 
18.05 
4.68 
1.19 
0.91 
6.47 

15.04 
17.95 
5.88 
27.00 
7.01 
1.78 
1.37 
9.69 

37.84 
45.17 
14.20 
67.90 
17.65 
4.49 
3.44 
24.38 

$10,240 
12,230 
4,005 
18,380 
4,780 
1,216 
931 
6,600 

$2,162 
2,580 
846 
3,880 
1,008 
256 
196 
1,392 

$1,005 
1,200 
393 
1,805 
468 
119 
91 
647 

$1,263 
1,507 
494 
2,267 
589 
149 
115 
814 

$2,270 
2,710 
852 
4,074 
1,065 
269 
206 
1,463 

Total  

1,442 

182.46 

61.60 

57.28 

85.72 

215.07 

$58,382 

$12,320 

$5,728 

$7,198 

$12,909 

Grand  Totals,  per  24  Hours:  Weight,  602.13  Tons;  Value,  $96,537. 

Per  Year:  Weight,  219,777  Tons;  Value, 
$35,236,005. 

*  In  making  out  this  table,  account  has  been  taken  of  the  greater  dilution,  149  gallons  per  capita  instead  of  125 
gallons,  as  in  1910.    Quantities  per  million  gallons  are  therefore  taken  as  125-150  of  the  same  values  for  1910. 


Any  process  which  is  to  become  effective  for  the  utilization  of  sewage  must  comply 
with  the  sanitary  requirements  which  may  reasonably  be  prescribed  and,  in  doing  so, 
must  answer  to  a  number  of  demands  which  are  seldom  made  in  the  conduct  of  a  suc- 
cessful business  enterprise.  Prominent  among  these  requirements  is  the  necessity  for 
utilizing  the  sewage  as  it  comes  to  the  works  in  spite  of  the  variations  in  volume  and  in 
composition  which  occur.  This  variation  is  reduced  to  a  minimum  where  the  works 
are  located  at  a  long  distance  from  the  point  of  origin  of  the  sewage  and  where  the 
sewage  is  a  mixture  from  various  sections  of  the  city.  Both  the  long  distance  traveled 
and  the  mixing  are  likely  to  serve  usefully  in  counteracting  such  changes  in  composi- 
tion as  always  occur  when  the  sewage  is  derived  from  small  areas. 

If  the  works  are  to  utilize  all  the  sewage,  it  is  necessary  that  they  shall  be  elastic 
in  capacity  in  order  to  accommodate  themselves  to  the  variations  in  flow.  If  the 
process  of  utilization  is  mechanical  or  chemical  in  character,  the  necessary  elasticity 
may  often  be  readily  secured,  but  where  the  process  involves  biological  action  as,  for 
example,  application  to  land,  serious  embarrassment  from  the  fluctuations  may  result. 

From  the  composition  of  sewage,  it  is  evident  that  of  all  the  constituents  nor- 
mally present,  the  water  and  those  substances  which  may  be  of  value  to  growing 
plants  are  likely  to  be  the  most  useful.  The  mineral  part  of  the  suspended  matter, 
like  the  forms  of  life  which  are  present,  is  only  incidental  and  of  no  advantage  theoret- 
ically or  practically.    Among  the  useful  ingredients,  the  water  is  in  some  cases  the 


UTILIZATION  OF  SEWAGE  351 

most  valuable  material  which  sewage  contains,  but  this  value  exists  only  in  those  situ- 
ations where  the  land  needs  water. 

Among  the  plant  foods  which  sewage  contains,  the  nitrogen  compounds  are  the 
most  important. 

The  recovery  of  grease,  except  where  the  sewage  is  known  to  be  particularly  rich 
in  this  ingredient,  is  not  regarded  as  an  economical  procedure. 

Aside  from  the  application  of  sewage  to  farm  land,  the  idea  of  utilization  carries 
with  it  the  necessity  of  extracting  the  useful  ingredients  in  the  form  of  sludge  and  re- 
solving this  into  a  form  in  which  the  solids  can  conveniently  be  stored  and  trans- 
ported. The  presence  of  the  water,  overwhelming  in  volume  and  resistant  by  reason 
of  its  molecular  combination  with  the  fine  gelatinous  particles  of  suspended  matter,  is 
a  problem  of  peculiar  difficulty. 

THE  NITROGEN  PROBLEM 
Importance  of  Nitrogen 

The  fundamental  theory  upon  which  attempts  have  been  made  to  utilize  the 
manurial  ingredients  of  sewage  has  been  based  upon  the  belief  that  the  nitrogen  was 
worth  saving. 

Nitrogen  is  one  of  the  most  important  elements  entering  into  the  food  of  men  and 
animals.  It  is  a  valuable  constituent  of  plant  foods  and  enters  largely  into  the  com- 
position of  meat.  It  is  thrown  off  by  animals  with  their  excrement  and  is  to  some 
extent  returned  to  the  soil  from  which  it  is  derived. 

The  term  nitrogen  specifies  nitre-producer  and  was  suggested  by  the  fact  that 
nitrogen  is  an  ingredient  of  saltpeter  which  is  known  among  chemists  as  potassium 
nitrate.  Saltpeter  has  been  employed  in  various  ways  for  many  centuries.  It  occurs 
as  an  efflorescence  upon  the  earth  as  a  result  of  the  oxidation  of  organic  nitrogenous 
matter  in  the  presence  of  potash  in  the  soil.  It  is  occasionally  found  in  the  neighbor- 
hood of  villages,  more  especially  in  hot  climates,  where  urine  and  other  readily  pu- 
trescible  organic  matters  rich  in  nitrogen  exist. 

Consumption  of  Nitrogen  Compounds  in  Agriculture  and  in  the  Arts 

The  commercial  demand  for  nitrogen  compounds  arises  chiefly  from  the  require- 
ments of  agriculture  and  certain  chemical  industries.  Some  idea  of  the  extent  of  this 
demand  may  be  obtained  from  the  fact  that  the  United  States  sends  annually  abroad 
over  |32,000,000  for  the  purchase  of  nitrogen  in  various  combinations.  The  principal 
demand  is  for  the  manufacture  of  fertilizers.    Coal-tar  dyes  to  the  value  of  over 


352         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

$6,000,000  are  annually  imported  into  the  United  States.  In  addition,  indigo  in  value 
exceeding  $1,000,000  is  brought  into  this  country,  and  nitrogen,  for  the  preparation 
of  explosives,  is  imported  to  an  extent  exceeding  $1,000,000.  In  the  year  1910,  the 
imports  of  crude  nitrogen  compounds  into  the  United  States  for  various  purposes 
were  approximately  as  shown  in  Table  LI. 

TABLE  LI 

Value  of  Crude  Nitrogen  Compounds  Imported  into  the  United  States  in  1910 


Sodium  nitrate   $16,548,000 

Ammonium  salts   3,771,000 

Guano   820,000 

Anilin  oil  and  salts   715,000 

Coal-tar  dyes   6,016,000 

Coal-tar  derivatives   800,000 

Explosives   1,003,000 

Indigo   1,224,000 

Potassium  nitrate   791,000 

Miscellaneous   696,000 


Total   $32,384,000 


In  addition  to  the  foregoing,  large  quantities  of  fertilizers  are  employed  in  the 
form  of  natural  manures.  Manufactories  have  recently  been  erected  for  the  synthetic 
production  of  nitrogen  compounds  and  the  products  of  these  should  be  included  in 
estimating  the  total  consumption  of  fertilizing  materials.  Finally,  in  every  large  city 
there  are  places  where  bones,  slaughter-house  wastes  and  offal  are  rendered  into  fer- 
tilizing materials  and  the  aggregate  of  their  product  is  not  to  be  neglected. 

Main  Sources  op  the  Nitrogen  Compounds 

Most  of  the  nitrogen  compounds  which  are  used  as  manure  are  derived  from  cer- 
tain natural  supplies  of  fixed  nitrogen,  of  which  Chili  saltpeter  is  an  example,  and  the 
fixation  of  nitrogen  from  the  unlimited  supplies  of  this  gas  which  exist  in  the 
atmosphere. 

natural  sources 

Chili  Saltpeter.  The  most  important  single  source  of  combined  nitrogen  in  the 
world  at  the  present  time  is  the  deposit  of  sodium  nitrate  which  exists  in  Chili.  These 
deposits  are  believed  to  have  been  formed  by  the  decomposition  of  seaweed  and 
marine  refuse  through  favorable  conditions  of  temperature  and  the  activity  of  nitrifying 
bacteria. 

Saltpeter.  Potassium  nitrate,  or  saltpeter,  is  produced  when  organic  matter, 
such  as  urine  or  excrement,  decays  through  the  action  of  bacteria  in  the  presence  of 
potassium  carbonate.   It  has  often  been  an  important  source  of  one  of  the  chief  in- 


UTILIZATION  OF  SEWAGE  353 

gredients  of  gunpowder  at  times  of  warfare  and  up  to  about  one  hundred  years  ago 
was  practically  the  only  source  of  combined  nitrogen  available.  About  20,000  tons  are 
produced  in  India,  the  cost  being  about  $75  per  ton. 

The  natural  occurrence  of  potassium  nitrate  and  its  continued  formation  in  cer- 
tain regions  of  the  world  is  so  slight  as  to  constitute  no  serious  factor  in  business, 
but  the  conditions  which  are  most  favorable  for  the  production  of  these  nitrates  are 
worth  considering  from  the  standpoint  of  sewage  utilization.  There  are  said  to  be 
needed  (a)  porous  earth  which  will  allow  easy  access  of  air  and  water;  (b)  moisture 
sufficient  to  prevent  dryness;  (c)  an  abundant  supply  of  decaying  organic  matter  rich 
in  nitrogen;  (d)  temperatures  ranging  from  5  to  55  degrees  C.  with  37  degrees  as  the 
most  favorable  and  (e)  weak  alkalinity  of  the  soil  due  to  the  presence  of  carbonates, 
potassium,  calcium  or  magnesium. 

Guano.  Guano  is  a  nitrogenous  organic  compound  which  occurs  in  large  natural 
deposits  and  is  highly  valued  as  a  fertilizer.  Its  value  lies  not  alone  in  the  fact  that 
it  contains  combined  nitrogen,  but  it  possesses  a  useful  amount  of  phosphoric  acid 
which  is  one  of  the  most  important  manurial  ingredients.  The  chief  sources  of  guano 
are  the  islands  and  coasts  of  tropical  and  semitropical  America,  Africa,  Oceana, 
Patagonia  and  Labrador,  and  it  is  said  that  an  island  off  the  Mexican  coast,  contain- 
ing a  deposit  of  about  10,000,000  tons,  is  being  operated  by  an  American  company. 
Deposits  of  guano  are  made  up  of  the  excrement  of  birds. 

Coal.  The  largest  natural  supplies  of  combined  nitrogen  which  exist  are  con- 
tained in  deposits  of  coal.  Anthracite  coal  contains  from  y2  to  1  per  cent,  of  nitrogen, 
bituminous  coal  y2  to  iy2  per  cent,  and  brown  coal  from  1  to  2  per  cent.  Most  of  the 
nitrogen  which  is  contained  in  coal  can  be  recovered  by  dry  distillation,  as  in  the 
manufacture  of  gas,  a  part  being  given  off  as  ammonia  and  another  as  free  nitrogen. 
If  all  of  the  1,000,000,000  tons  of  coal  annually  produced  were  distilled  before  it  was 
used  as  fuel,  it  would  yield  at  least  50,000,000  tons  of  pure  ammonium  sulphate,  which 
has  a  current  market  value  of  over  $50.00  per  ton.  The  amount  of  commercial  am- 
monium sulphate  actually  secured  from  coal  was  about  1,100,000  tons  in  the  year  1910. 

Peat  and  Silt.  In  addition  to  the  stores  in  coal,  large  supplies  of  combined 
nitrogen  exist  in  the  vegetable  matter  which  is  undergoing  slow  decomposition  in  vari- 
ous parts  of  the  world  in  the  form  of  peat  and  silt.  The  world's  supply  of  peat  is 
enormous  and  increasing.  At  present  about  10,000,000  tons  are  used  annually  as  fuel. 
Dried  peat  contains  about  1  per  cent,  of  nitrogen  and  it  can  be  used  for  fuel  in  such  a 
way  that  about  three-quarters  of  this  nitrogen  can  be  recovered  as  ammonium  sulphate. 

City  Refuse.  The  vegetable  and  animal  refuse  of  cities,  aside  from  the  sewage,  is 
often  rich  in  nitrogen  and  in  some  cases  this  nitrogen  can  be  utilized.    The  waste  of 


354        DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

sugar  works  and  distilleries,  slaughter  houses,  as  well  as  of  households  and  markets, 
contains  compounds  in  which  nitrogen  exists  in  various  combinations.  Much  of  this 
nitrogenous  refuse  is  either  in  a  state  of  decomposition  or  ready  to  proceed  upon  that 
course.  The  nitrogen  is  fixed,  but  beyond  that  fact  and  the  circumstance  that  its  com- 
plicated chemical  combinations  can  be  changed  into  useful  forms,  the  refuse  is  of  prac- 
tically no  value  in  agriculture.  Before  extracting  the  serviceable  ingredients  of  city 
refuse,  it  is  necessary  to  pass  it  through  some  such  process  as  dry  distillation  for  the 
recovery  of  ammonium  sulphate  or  putrefactive  fermentation. 

ARTIFICIAL  SOURCES 

The  demand  for  nitrogen  in  chemical  combinations  suitable  for  use  as  fertilizer 
and  in  the  arts  has  led  to  the  invention  of  a  number  of  processes  for  the  recovery  of 
nitrogen  from  the  atmosphere  and  the  transformation  of  this  nitrogen  into  suitable 
compounds. 

All  these  processes  require  great  heat  and  this  is  usually  supplied  by  some  form 
of  electric  flame.  The  opportunities  for  the  electric  recovery  of  nitrogen  are  best  in 
those  places  where  large  amounts  of  electrical  power  can  be  obtained  cheaply.  Works 
on  a  large  scale  exist  in  Norway,  Italy  and  in  America. 

Mond  Gas.  It  has  been  shown  practically  that  a  large  amount  of  the  nitrogen  in 
coal  can  be  recovered  in  the  form  of  ammonia  in  the  production  of  water  gas.  An 
essential  feature  of  the  process  is  the  introduction  of  steam  superheated  to  150°  C. 
into  the  generators.  Fully  one-half  of  the  nitrogen  present  is  obtained  in  the  form  of 
ammonia.  A  short  ton  of  coal  is  said  to  yield  an  average  of  6.6  pounds  of  ammonium 
sulphate. 

The  Mond  process  has  spread  rapidly  in  England,  where  there  are  60  plants  using 
over  a  million  tons  of  coal  annually.  Of  these  plants  15  are  fit  for  the  collection  of 
ammonia.  The  yield  of  sulphate  in  1909  was  over  26,000  tons.  Other  plants  are 
located  in  Germany. 

HUMAN  EXCREMENT  VERSUS  OTHER  FERTILIZERS 

The  introduction  of  guano  in  the  early  part  of  the  nineteenth  century  produced 
a  decided  change  in  the  custom  of  agriculturalists  in  the  use  of  locally  produced 
manure.  There  was  for  the  first  time  made  available  in  concentrated  form  a  fertiliz- 
ing material  which  was  reasonably  inexpensive,  convenient  to  handle  and  capable  with 
ordinary  care  of  being  preserved  for  a  long  period  of  time  and  transported  with  little 
difficulty  and  expense. 


UTILIZATION  OF  SEWAGE  355 

The  appearance  of  guano  in  the  market  was  followed  by  the  introduction  of  other 
manures  possessing  equally  valuable  properties.  At  the  present  time  the  home-made 
manures  of  the  farm  can,  in  the  average  case,  compare  but  poorly  with  the  purchased 
product.  It  has  been  well  said  that  farmyard  manure  of  average  quality  is  of  so  little 
value  that  it  is  not  worth  while  to  pay  the  transportation  charges  upon  it  except  for  a 
few  miles  from  its  point  of  origin. 

Had  it  not  been  for  the  introduction  of  guano  and  other  concentrated  fertilizers, 
it  is  doubtful  whether  the  present  methods  of  sewerage  and  disposal  of  city  wastes 
would  have  found  the  common  usage  which  they  now  enjoy.  It  would  have  been 
thought  necessary  to  conserve  the  excrement  of  the  human  population  of  cities  and 
towns  instead  of  allowing  it  to  go  to  waste,  as  has  been  prevalent  in  Northern  Europe 
and  America  for  the  last  sixty  years.  The  fact  that  the  excrement  is  removed  by  water 
and  so  little  care  taken  to  preserve  it  in  form  for  agricultural  use  is  in  itself  testi- 
mony that  its  value,  as  shown  by  the  practical  experience  of  agriculturalists,  is  not 
great. 

The  excrement  of  carniverous  animals,  of  which  man  forms  an  example,  is  con- 
ceded to  have  greater  manurial  value  than  that  of  the  domestic  animals  whose  diet  con- 
sists exclusively  of  vegetable  matter,  larger  quantities  of  nitrogen  being  contained  in 
it,  yet  is  not  so  valuable  as  commonly  supposed. 

Factors  Influencing  the  Value  op  Fertilizers 

The  conditions  which  determine  the  value  of  any  fertilizer  include  not  only  the 
composition  of  the  material  but  its  stability  on  storage,  its  capacity  for  transportation, 
the  convenience  with  which  it  can  be  employed  and  the  competition  in  the  way  of 
price  which  it  must  meet  from  other  fertilizers. 

In  regard  to  composition,  it  is  necessary  that  the  fertilizer  shall  contain  certain 
chemical  compounds  which  are  required  by  the  growing  plants.  Along  with  the  needed 
ingredients  there  must  be  no  harmful  properties.  It  is  not  sufficient  that  there  are  the 
chemical  elements  needed  for  plant  growth.  They  must  be  present  in  suitable  form  for 
ready  assimilation  by  the  crops.  It  is  not  sufficient  that  a  fertilizer  shall  contain  a 
requisite  amount  of  nitrogen.  Many  of  the  compounds  of  nitrogen  are  of  little  or  no 
use  and  must  either  be  converted  into  assimilable  substances  in  the  soil  or  they  are 
wasted,  so  far  as  the  fertilizer  is  concerned. 

One  of  the  difficulties  which  must  be  overcome  before  human  excrement  can  seri- 
ously compete  with  artificial  fertilizers  lies  in  the  amount  of  water  which  fresh  excre- 
ment contains.  This  water  is  in  no  wise  useful.  On  the  contrary,  it  adds  to  the  bulk 
and  weight  of  the  material  and  favors  decomposition  changes  which  are  likely  either 


356         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


to  lead  to  the  production  of  offensive  odors  or  the  escape  of  much  of  the  valuable 
nitrogenous  content.  It  is  with  difficulty  that  the  water  can  be  expelled.  It  may  be 
driven  off  by  heat,  but  this  is  expensive  and  may  result  in  the  evaporation  of  some  of 
the  useful  properties.  The  water  can  be  withdrawn  by  means  of  absorbing  agents, 
such  as  dry  earth  or  chalk,  but  such  desiccators  are  in  themselves  weighty  and  can- 
not readily  be  separated  from  the  excrement.  These  remarks  refer  particularly  to 
fecal  matter.  Urine,  when  considered  from  the  standpoint  of  the  quantity  produced 
per  capita  per  day,  contains  much  more  fertilizing  material  than  fecal  matter  but  is 
more  difficult  to  deal  with. 

Stability  on  Storage.  From  what  has  been  said  under  the  last  heading,  it  will  be 
evident  that  there  are  serious  difficulties  in  the  way  of  storing  excrement  without  im- 
pairing its  manurial  value  and  in  any  scheme  of  utilization,  storage  for  considerable 
periods  of  time  must  play  an  important  part. 

The  needs  of  vegetation  require  that  fertilizer  shall  be  applied  only  at  certain 
seasons;  during  the  rest  of  the  time,  it  must  be  stored  in  a  situation  from  which  it 
can  be  transported  to  the  fields  without  great  cost,  inconvenien.ee  or  loss.  Unless 
dried  or  preserved  in  hermetically-sealed  containers,  the  loss  by  evaporation  on  storage 
may  be  considerable. 

Transportation.  No  fertilizer  can  be  profitably  used  unless  the  charges  which 
have  to  be  incurred  for  transporting  it  from  its  source  to  its  destination  are  reason- 
able. The  cost  of  transportation  has  probably  operated  more  to  prevent  the  utiliza- 
tion of  excrement  than  any  other  une  thing. 

Various  ingenious  devices  have  been  invented  to  transport  excrement  from  its 
points  of  origin  to  its  points  of  utilization.  The  dry  conservancy  system  has  had  con- 
siderable popularity  in  England.  The  tinnettes  of  France  and  Belgium  and  the 
vacuum  sewerage  system  of  Liernur  are  the  best  practicable  measures  which  have  been 
employed  for  the  transportation  of  excrement  without  water  up  to  the  present  time. 

No  system  has  proved  so  effective  as  water  carriage.  As  applied  to  cities,  the 
advantages  of  water  carriage  are  so  obvious  that  municipalities  are  content  to  spend 
large  sums  to  obtain  the  water  which  is  necessary  in  order  that  modern  sewerage 
systems  can  be  employed. 

The  water  carriage  of  excrement  introduces  a  serious  difficulty  into  the  problem 
of  utilizing  human  excrement.  It  is  capable  of  facilitating  the  distribution  of  the 
fertilizing  material  upon  land,  but  it  adds  immensely  to  the  obstacles  with  which  the 
useful  ingredients  may  be  extracted  and  concentrated  in  a  form  which  is  suitable  for 
storage  or  long-distance  transportation. 

Convenience.    It  cannot  be  too  strongly  emphasized  that  convenience  plays  a  lead- 


UTILIZATION  OF  SEWAGE 


357 


ing  part  in  determining  the  value  of  a  fertilizer.  It  is  convenience  which  requires 
that  the  fertilizer  be  of  suitable  composition  and  capable  of  storage  and  transporta- 
tion. Convenience  demands  that  the  material  which  is  used  shall  be  in  a  form  which 
can  readily  be  distributed  over  the  fields  or  in  furrows,  as  the  requirements  of  the 
crops  demand.   If  too  bulky  and  heavy,  an  excessive  amount  of  labor  will  be  required. 

Competitio7i  with  Artificial  Fertilizers.  In  the  last  analysis  the  value  of  human 
excrement  as  a  fertilizer  will  be  found  to  depend  upon  the  cost  of  other  fertilizers 
which  are  capable  of  answering  the  same  purpose. 

Most  Desirable  Constituents  op  Fertilizers 

The  chemical  analysis  of  plants  shows  of  what  they  are  composed  and  furnishes  a 
key  to  the  food  which  should  be  supplied  to  them. 

The  most  important  ingredient  from  the  standpoint  of  weight  is  water,  a  fact 
which  is  of  considerable  interest  from  the  standpoint  of  utilizing  sewage.  Crops  such 
as  are  likely  to  be  grown  with  the  aid  of  excrement  contain  from  30  to  70  or  even  80 
per  cent,  of  water,  depending  largely  upon  their  physical  constitution.  Turnips  and 
mangolds  which  are  extensively  grown  on  sewage  farms  in  England  contain  so  much 
water  that  the  solid  dry  material  in  one  ton  scarcely  weighs  more  than  an  average  man. 

The  water  of  plants  is  almost  exclusively  derived  from  the  soil.  It  is  absorbed  by 
the  roots,  a  fact  which  should  be  kept  in  mind  in  sewage  farming,  since  a  frequent  sub- 
mergence of  the  leaves  of  some  vegetables  seriously  injures  them. 

An  essential  element  in  the  composition  of  vegetable  matter  is  carbon.  So  uni- 
versal is  this  element  in  the  complex  structure  of  living  things  that  the  science  of 
organic  chemistry  has  been  described  as  the  chemistry  of  the  carbon  compounds. 

From  the  soil  are  obtained  potash,  lime,  iron,  silica  and  various  other  elements 
which  are  required  in  lesser  degree.  The  important  ingredient,  nitrogen,  upon  the 
supply  of  which  the  vigor  and  abundance  of  growth  so  largely  depends,  is  obtained  by 
most  plants  from  soluble  compounds  in  the  soil.  In  certain  cases,  as  clover  and  other 
leguminous  plants,  nitrogen  is  absorbed  from  the  atmosphere  contained  in  the  pores  of 
the  soil,  certain  forms  of  bacteria  playing  an  important  part  in  preparing  the  nitrogen 
for  assimilation. 

Function  of  the  Soil.  The  soil  serves  two  principal  uses  in  agriculture.  It  affords 
a  suitable  standard  of  support  in  which  the  plants  can  establish  a  footing  and  it  acts 
as  a  laboratory  and  reservoir  for  the  preparation  and  storage  of  such  chemical  sub- 
stances as  the  plants  require  for  growth. 

Practically  all  the  food  of  plants  can  be  assimilated  only  from  dilute  solutions. 
When  fertilizers  of  any  kind  are  applied  to  a  field,  they  must  first  be  dissolved  by 


358         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

water  before  they  can  be  appropriated  by  vegetation.  Fertilizers  differ  largely  in  re- 
spect to  solubility  and  this  fact  requires  to  be  taken  into  consideration  in  determining 
at  what  season  of  the  year  the  fertilizing  material  is  to  be  employed.  Farmyard 
manure  which  has  to  decompose  and  be  resolved  slowly  into  liquid  form  is  usually 
applied  in  the  autumn,  whereas  the  ammonia  and  nitric  acid  compounds,  if  applied  so 
long  in  advance  of  the  requirements,  are  likely  to  leach  away  before  they  can  be  used. 
With  sewage  there  is  no  choice  as  to  the  time  of  application.  It  must  be  employed 
when  produced  or  not  at  all. 

The  Most  Needed  Compounds.  The  three  most  important  ingredients  of  fertilizers 
are  nitrogen,  phosphoric  acid  and  potash.  In  commercial  fertilizers,  the  nitrogen  is 
usually  present  in  the  form  of  ammonia  or,  as  sold  in  the  market,  sulphate  of  ammonia. 
The  nitric  acid  is  most  often  sold  in  the  form  of  nitrate  of  soda.  Seventeen  parts  of 
ammonia  or  66  parts  of  pure  sulphate  of  ammonia  contain  14  parts  of  nitrogen. 

Phosphoric  acid  is  derived  from  materials  called  phosphates,  in  which  it  may 
exist  in  combination  with  lime,  iron  or  alumina.  Phosphate  of  lime  is  the  form  most 
largely  used.  Phosphoric  acid  occurs  in  fertilizers  in  three  forms:  (1)  That  which  is 
soluble  in  water  and  is  readily  taken  up  by  plants;  (2)  that  which  is  slightly  soluble 
in  water,  but  still  readily  assimilated  by  plants  and  is  sometimes  known  as  "reverted"; 
and  (3)  that  which  is  very  sparingly  soluble  in  water  and  is  consequently  slowly  used 
by  plants.  A  fourth  form,  sometimes  called  odorless  phosphate,  is  practically  insoluble 
in  water,  but  dissolves  in  the  presence  of  certain  salts  or  plant  acids  and,  therefore, 
becomes  useful  as  a  ready  source  of  phosphoric  acid  when  applied  to  the  soil.  This  and 
the  soluble  and  reverted  types  are  known  as  available  phosphoric  acid. 

Organic  phosphates  are  contained  in  bone, which  is  now  the  only  one  of  the  so-called 
insoluble  phosphates  that  is  not  largely  used  without  other  change,  and  it  is  prepared 
by  mechanical  action  such  as  grinding.  Other  phosphates  from  bone,  such  as  bone- 
black,  bone  ash,  etc.,  are  little  used. 

The  term  tankage  is  applied  to  the  dried  and  ground  animal  wastes  of  abattoirs 
and  packing  establishments.  The  material  is  thus  designated  because  it  is  the  residual 
product  after  the  waste  portions  of  the  carcass  are  steamed  under  pressure  in  large 
tanks  for  the  extraction  of  the  fatty  substances. 

The  mineral  phosphates  differ  from  so-called  organic  phosphates  in  that  they  con- 
tain no  organic  or  animal  matter  and  are  more  compact.  They  are  extensively  derived 
from  river  and  land  phosphate  beds  in  South  Carolina,  Florida  and  Tennessee  and 
phosphatic  slag  which  is  a  waste  product  from  the  manufacture  of  steel  from  certain 
iron  ores.   All  except  the  slag  are  treated  with  acid  before  use. 

Super-phosphates  or  soluble  phosphates  are  derived  from  the  insoluble  materials 
by  grinding  them  to  a  powder  and  mixing  them  with  sulphuric  acid.    The  term  super- 


UTILIZATION  OF  SEWAGE 


359 


phosphate  is  applied  to  any  material  containing  soluble  phosphoric  acid  as  its  chief 
constituent. 

Potash  exists  chiefly  as  chlorides  or  muriates  and  as  sulphates.  The  form  does 
not  exert  so  great  an  influence  upon  the  availability  of  the  potash  as  in  the  case  of 
nitrogen  and  phosphoric  acid.  All  forms  used  in  the  fertilizer  industry  are  freely 
soluble  in  water  and  are  believed  to  be  nearly,  if  not  quite  equally,  available  as  plant 
food. 

The  chief  sources  of  potash  salts  are  the  potash  mines  of  North  Germany.  Kainit 
and  sylvinit  are  crude  products  of  the  mines.  The  mine  products  may  be  used  in  crude 
condition,  or,  after  chemical  treatment,  in  the  form  of  various  salts. 

Potash  salts  are  used  to  best  advantage  on  light,  sandy  humus  and  calcareous  soils. 

Standard  materials  in  the  fertilizer  industry  are  those  which  do  not  show  a  wide 
variation  in  composition  and  in  which  the  constituents  are  practically  uniform  in  ac- 
tion. Nitrate  of  soda,  sulphate  of  ammonia,  dried  blood  and  super-phosphates  .and 
potash  salts  are  all  standard  products,  as  they  can  be  depended  upon  both  as  to  pro- 
duct and  the  form  of  their  constituents.  Ground  bone,  on  the  other  hand,  is  non- 
standard, because  it  is  variable  in  composition  and  in  the  availability  of  its  nitrogen 
and  phosphoric  acid. 

The  agricultural  value  of  a  plant  food  is  not  a  fixed  quantity.  It  varies  according 
to  the  availability  of  the  constituents,  as  well  as  upon  the  value  of  the  crop.  It  should 
be  based  upon  the  crop  increase  which  its  use  produces. 

The  agricultural  value  should  not  be  confused  with  the  commercial  value  or  cost 
of  the  fertilizer  in  the  market.  The  latter  is  determined  by  market  and  trade  condi- 
tions, as  the  cost  of  the  crude  materials  and  the  methods  of  their  subsequent  treatment. 
The  commercial  value  does  not  necessarily  bear  a  direct  relation  to  the  agricultural 
value. 

The  computation  of  the  commercial  value  of  complete  fertilizers  is  illustrated  in 
the  following  table. 

TABLE  LII 

Methods  of  Computing  Values  of  Complete  Fertilizers 


Constituent 

Pounds 
per  Hundred 

Pounds 
per  Ton 

Value 
per  Pound  of 
Constituent 

Value  of 
Constituent  per 
Ton  of  Fertilizer 

Nitrogen: 

Cents 

As  nitrate  

1 

20 

17.0 

$3.40 

As  ammonia  salts  

1 

20 

17.5 

3.50 

As  organic  matter  

1 

20 

18.5 

3.70 

Phosphoric  acid: 

Soluble  

8 

160 

4.5 

7.20 

1 

20 

4.5 

.90 

1 

20 

2.0 

.40 

Potash: 

5 

100 

4.25 

4.25 

5 

100 

5.0 

5.00 

$28.35 

360         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


The  first  figure  column  shows  the  per  cent,  (pounds  per  hundred)  of  the  constit- 
uents contained  in  the  fertilizer;  the  per  cent,  multiplied  by  20  gives  the  pounds  per 
ton  in  the  second  column ;  the  figures  in  the  latter,  multiplied  by  the  schedule  prices 
per  pound  in  the  third  column,  give  the  valuation  per  ton,  as  shown  in  the  fourth 
column. 

The  direct  value  of  a  fertilizer  is  determined  by  the  percentage  of  nitrogen,  phos- 
phoric acid  or  potash  which  it  contains,  hence  the  buying  of  a  fertilizer  is  virtually  the 
buying  of  one  or  more  of  these  constituents.  The  more  concentrated  the  material,  the 
less  will  be  the  proportionate  expense  of  handling  it.  As  a  rule,  farmers  are  inclined  to 
purchase  fertilizers  on  the  ton  basis  without  regard  to  the  amount  or  form  of  the  con- 
stituents contained  in  them. 

High  grade  mixtures  cannot  be  made  from  low  grade  materials.  The  following 
table  illustrates  the  methods  by  which  brands  of  fertilizers  may  be  made  up. 

TABLE  LIII 
Formula  for  Making  Fertilizer 

Pounda  Pounds      Per  Cent. 

Nitrate  of  soda   500,  furnishing  nitrogen   80,    or  4 

Boneblack  super-phosphate. . .  1,100,  furnishing  phosphoric  acid.  ..  .  180,  or  9 
Muriate  of  potash   400,  furnishing  potash   200,    or  10 

Total   2,000,  furnishing  total  plant  food. ...  460 

This  formula  shows  a  high  grade  product  both  as  to  quality  of  plant  food  and  con- 
centration. 

The  charges  of  manufacturers  and  dealers  for  mixing,  bagging,  shipping  and  other 
expenses  are  said  to  be  on  an  average  about  $7  per  ton,  and  the  average  actual  fertiliz- 
ing constituents  per  ton  are  said  to  weigh  about  300  pounds. 

The  foregoing  remarks  upon  commercial  fertilizing  materials  are  based  upon 
Farmers'  Bulletin  No.  44,  by  Edward  B.  Voorhees,  U.  S.  Department  of  Agriculture. 

The  Composition  of  Human  Excrement 
The  composition  of  excrement  as  collected  by  city  scavengers  depends  greatly 
upon  the  methods  of  collection,  the  presence  or  absence  of  other  materials  and  the  cir- 
cumstances under  which  the  excrement  has  been  kept  until  the  time  of  collection. 
Leaching  and  fermentation  are  capable  of  materially  changing  the  fertilizing  value 
of  the  mass. 

Analyses  of  Feces  and  Urine.  In  a  general  way  it  may  be  said  that  solid  human 
excreta  as  they  leave  the  body  contain  about  one-fourth  of  their  weight  of  dry  matter 
and  three-fourths  water.  The  dry  matter  contains  about  l1/^  per  cent,  of  nitrogen 
and  1  per  cent,  of  phosphoric  acid. 


UTILIZATION  OF  SEWAGE 


361 


According  to  Professor  Way,  formerly  consulting  chemist  of  the  Royal  Agricul- 
tural Society  of  England,  human  feces  contain  the  ingredients  shown  in  Table  LIV. 

TABLE  LIV 
Composition  op  Human  Feces 

If  Dried  Without 

In  Fresh  Condition  Loss  of  Fertilizing 

Properties 

Water                                                       75.00%   % 

Organic                                                       22.13  88.52 

Insoluble  silicious  matter                                     .37  1.48 

Oxide  of  iron                                                  .13  .54 

Lime                                                              .43  1 .72 

Magnesia                                                      .38  1.55 

Phosphoric  acid                                               1.07  4.27 

Sulphuric  acid                                                   .06  .24 

Potash                                                            .30  1.19 

Soda                                                            .08  .31 

Chloride  of  soda                                                .05  .18 

 100%   100% 

Containing  nitrogen  1.50  Containing  nitrogen  6.00 
equivalent  to  ammonia  equivalent  to  ammonia 
1.82  7.28 

If  perfectly  dry,  2  tons  of  solid  human  excreta  are  worth  about  as  much  as  1  ton 
of  Peruvian  guano.  The  urine  is  more  valuable  on  account  of  its  urea.  Urine  con- 
tains nearly  50  per  cent,  of  nitrogen  and  a  considerable  amount  of  phosphoric  acid. 

According  to  Professor  Way,  the  solid  ingredients  of  urine  are  as  shown  in  Table 

LV. 

TABLE  LV 
Composition  of  Human  Urine 

Organic  matter   67.54% 

Insoluble  material   .09 

Oxide  of  iron   .05 

Lime   .61 

Magnesia   .47 

Phosphoric  acid   4.66 

Sulphuric  acid   .46 

Potash   1.83 

Chloride  of  potash   5.41 

Chloride  of  sodium   18 .88 

 100% 

Containing  nitrogen  19.43 
equivalent  to  ammonia  23.60 

Notwithstanding  the  large  proportion  of  water,  the  solid  matter  voided  in  urine 
in  a  day  is  just  about  one-third  greater  than  the  amount  of  dry  matter  in  the  daily 
solid  evacuations.  Five-sixths  of  the  ammonia  which  is  capable  of  being  generated 
by  the  decomposition  of  human  excreta  is  furnished  by  the  urine. 

Professor  Way  found  that  one  adult  voids  in  24  hours  about  one-fourth  of  a 
pound  of  feces  and  3  pounds  of  urine.  Hence,  in  4  ounces  of  feces  there  is  1  ounce 
of  dry  matter  or  nearly  23  pounds  per  annum.  In  3  pounds  of  urine  there  is  1% 
ounce  of  dry  matter  or  nearly  34  pounds  per  annum.    The  ammonia  from  the  23 


362         DATA  KELATING  TO  THE  PROTECTION  OP  THE  HARBOR 


pounds  of  feces  amounts  to  1.60  pound  and  from  the  34  pounds  of  urine  8.12  pounds, 
or  a  total  amount  of  9.72  pounds  of  ammonia  per  year. 

Each  adult  furnishes  about  5y2  pounds  of  phosphates  per  year.  Briefly,  56  pounds 
of  dry  matter  is  produced  per  year,  containing  10  pounds  of  ammonia  and  5y2  pounds 
of  phosphoric  acid.  Allowing  16  cents  per  pound  for  the  ammonia  and  5  cents  per 
pound  for  the  phosphates  and  1  cent  per  pound  for  the  remaining  constituents,  gives  a 
total  value  for  the  excreta  per  capita  per  year  of  $2.27. 

Practical  Attempts  to  Utilize  Sewage 

In  China,  Japan,  Belgium,  France,  Italy  and  Spain,  and  in  some  parts  of  England 
there  appears  to  be  little  or  no  objection  caused  by  storing,  transporting  and  manip- 
ulating human  excrement,  but  in  America  the  case  is  different.  These  practices  are 
felt  to  destroy  the  self-respect  of  those  persons  who  are  engaged  in  them.  Those  whose 
business  it  is  to  clean  privies  and  cesspools  are  generally  regarded  with  aversion. 
They  often  carry  on  their  work  at  night  and  not  infrequently  with  an  appearance  of 
secrecy.  Nominally  under  the  jurisdiction  of  boards  of  health,  the  business  of  privy 
cleaning  is  too  often  conducted  with  little  more  regard  for  honesty  and  efficiency 
than  the  shrewd  judgment  of  the  scavengers  and  the  absence  of  oversight  deems  neces- 
sary. The  work  is  done  with  little  or  no  regulation  as  to  expense  and  seldom,  if 
ever,  until  absolutely  required. 

Such  manurial  value  as  the  contents  of  the  privies  and  cesspools  possess  is  usu- 
ally lost  in  America,  the  custom  being  for  the  scavengers  to  dump  the  material  into 
some  convenient  out-of-the-way  spot  without  any  other  idea  than  to  get  rid  of  it. 

It  is  probable  that  the  contents  of  American  privies  are  usually  of  inferior  worth, 
since  most  of  the  valuable  liquid  material  leaches  away  in  the  vault  and  there  is  cus- 
tomarily a  considerable  amount  of  ashes  and  other  refuse  intermixed  with  the  useful 
matters.  Furthermore,  owing  to  the  infrequency  with  which  the  receptacles  are 
cleaned,  fermentation  has  usually  occurred  with  the  result  that  much  of  the  more 
useful  manurial  property  has  been  converted  into  ammonia  and  nitrogen  gas  and  lost 
into  the  atmosphere. 

According  to  European  experience,  night  soil  is  a  relatively  concentrated  manure 
and  is  generally  applied  to  the  land  in  diluted  form.  It  is  often  mixed  with  other 
kinds  of  manure  and  so  serves  to  reinforce  the  nitrogen  of  the  latter  or,  it  may  be 
diluted  with  from  two  to  six  times  its  bulk  of  water  and  so  applied.  Sometimes  it  is 
dried  and  applied  as  powder,  as  was  once  done  in  Paris  and  other  cities.  Occasion- 
ally it  is  mixed  with  assorted  refuse  collected  from  the  streets  and  houses  and  com- 
posted, as  in  Holland. 


UTILIZATION  OF  SEWAGE  363 

Before  the  general  employment  of  water  to  carry  away  the  excrement  of  cities, 
many  attempts  were  made  to  chemically  treat  night  soil,  either  collected  in  com- 
bined condition  or  the  feces  and  urine  separately,  in  order  to  recover  the  useful  fer- 
tilizing ingredients,  and  various  processes  of  evaporation  were  employed  to  get  rid  of 
the  liquid  matters  and  recover  the  solids  in  relatively  concentrated  condition.  Among 
these  processes  is  that  known  as  Taffoe.  This  was  prepared  by  kneading  excrement 
and  loam  together,  moulding  the  mass  into  bricks  and  drying  the  latter  in  air. 

Another  process  mixed  excrement  with  magnesium  sulphate  and  sulphate  of  iron 
with  a  little  tar  and  potash  and  evaporated  the  clarified  liquid  by  permitting  it  to 
trickle  over  fagots  held  upon  a  frame,  as  is  done  at  some  places  to  recover  salt  from 
brine.  The  solid  matters  which  collected  upon  the  fagots  were  broken  up  and  sold. 

One  inventor  proposed  to  treat  fresh  excrement  with  smoke  in  order  to  prevent  it 
from  putrefying,  then  dry  it  partly  with  artificial  aid  and  partly  with  absorbents  and 
finally  mould  the  material  into  bricks  which  would  be  dried  in  air  and  finally  crushed 
to  powder. 

A  compound  known  as  urate  was  prepared  in  England  by  adding  gypsum  to  urine 
and  drying  the  precipitate  produced. 

Sulphate  of  urine  was  made  by  adding  enough  sulphuric  acid  to  stale  urine  to 
neutralize  the  ammonia  and  then  evaporating  the  liquid  to  dryness. 

Bolton  and  TVanklyn  proposed  to  drive  off  the  ammonia  from  urine  by  heat  and 
absorb  it  by  means  of  sulphate  of  lime,  thus  producing  sulphate  of  ammonia.  It  was 
once  believed  by  chemists  that  both  ammonia  and  phosphoric  acid  might  be  precip- 
itated from  urine  by  means  of  a  magnesium  salt  and  experiments  were  made  to  this 
end. 

Many  processes  have  been  employed  for  the  treatment  of  excrement  by  lime,  chiefly 
as  a  preservative  until  the  material  could  be  transported  to  fields  where  it  was  to  be 
employed. 

One  of  the  most  successful  chemical  processes  for  the  treatment  of  night  soil  is 
the  preparation  of  sulphate  of  ammonia,  as  practiced  in  Amsterdam.  The  principle 
is  to  add  lime  to  the  excrement  and  by  this  means  and  through  heat  drive  off  the 
ammonia  which  is  subsequently  absorbed  by  sulphuric  acid  with  the  ultimate  pro- 
duction of  a  clean,  white,  inoffensive  salt,  sulphate  of  ammonia. 

Among  the  best  known  fertilizers  produced  from  sewage  in  England  during  the 
period  when  the  manurial  value  of  sewage  was  considered  most  worthy  of  being  con- 
served was  the  product  called  native  guano  produced  by  the  ABC  process.  A  de- 
scription of  this  process  is  illustrative  of  many. 

The  ABC  process  received  skilful  and  adequate  attention  from  the  consulting 


364 


DATA  RELATING  TO  THE  PROTECTION  OP  THE  HARBOR 


chemist  of  the  Royal  Agricultural  Society  of  Englaud  at  a  time  when  the  product 
was  widely  advertised  and  offered  for  sale  at  $25  per  ton  at  any  railway  station  in 
England  or  Wales.  The  report  of  the  chemist,  A.  Voelcker,  F.R.S.,  was  published  in 
the  journal  of  the  society,  Volume  VI,  2nd  Series,  page  415. 

The  claim  of  the  company  was  that  it  could  extract  a  valuable,  dry,  artificial 
manure  from  liquid  sewage  and  render  the  sewage  as  clear  as  water  and  sufficiently 
pure  to  be  discharged  into  a  river  or  water  course  without  causing  any  nuisance.  The 
principle  was  to  add  a  precipitating  reagent  to  the  sewage  and  dry  the  resulting 
deposits.  The  reagents  consisted  of  alum,  blood,  clay,  magnesia,  manganate  of 
potash,  burnt  clay,  chloride  of  sodium,  animal  charcoal,  vegetable  charcoal  and  mag- 
nesium limestone.  The  proportions  in  which  these  ingredients  were  to  be  added 
varied  according  to  the  particular  sewage  to  be  treated.  The  resulting  deposit  was 
dried  in  centrifugal  machines  which  caused  a  reduction  of  about  50  per  cent,  of  the 
contained  water.  The  material  was  then  spread  out  in  thin  layers  to  the  sun  and  on 
becoming  sufficiently  dry  was  bagged  and  sent  out. 

Because  of  his  official  position  as  chemist  to  the  Agricultural  Society,  Voelcker  re- 
ceived a  number  of  samples  of  native  guano,  as  the  ABC  product  was  called.  He  found 
that  about  seven-eighths  of  the  useful  fertilizing  value  of  the  sewage  escaped  in  the 
dissolved  matter  and  one-eighth  only  remained  in  the  solids  in  suspension.  The  worth 
of  the  product  was  greatly  exaggerated.  The  value  varied  widely.  The  minimum  for 
the  samples  sent  to  him  was  about  $3.62  and  the  maximum  $8.11  per  ton.  To  use 
Voelcker's  language:  "At  these  prices  all  the  really  valuable  fertilizing  constituents 
in  a  ton  of  this  manure  may  be  purchased  in  a  concentrated  form  and  be  easily  car- 
ried by  a  lad  on  the  field  in  a  very  small  bag."  He  considered  it  better  to  compare  the 
material  with  ordinary  farmyard  manure  than  to  regard  it  as  a  compound  of  high  fer- 
tilizing value.  Four  of  the  samples  of  native  guano  examined  were  practically  worth- 
less if  carted  10  miles  from  the  place  where  they  were  manufactured. 

Poudrette.  The  process  of  drying  night  soil  in  order  that  it  may  be  transported 
and  used  for  fertilizer  was  at  one  time  carried  on  in  a  suburb  of  Paris  on  a  large  scale 
and  in  New  York  and  many  other  cities.  The  product  was  known  as  poudrette.  At 
Paris  some  old  quarries  supplied  the  site  where  the  material  was  prepared.  A  number 
of  the  excavations  were  used  as  settling  basins,  the  liquid  portion  running  off  and  the 
solid  matters  remaining  behind.  When  a  large  accumulation  of  solids  had  collected, 
they  were  removed  to  nearby  fields  and  spread  out  upon  the  land  to  dry,  the  process  of 
drying  being  facilitated  by  occasional  harrowing. 

The  final  result  was  a  dry,  inoffensive  powder  which  seems  not  really  to  have  had 
great  fertilizing  value,  but  was  so  convenient  to  use  and  appeared  to  contain  so  much 
of  value  that  the  production  of  poudrette  became  an  extensive  undertaking. 


UTILIZATION  OF  SEWAGE  365 

It  would  appear  that  changes  took  place  in  the  settling  basins  which  were  more 
than  mere  sedimentation  and  less  than  complete  septicization.  The  odors  produced  are 
said  to  have  been  exceptionally  offensive,  from  which  it  may  be  inferred  that  fermen- 
tation was  the  predominant  microbic  action  and  from  which  it  would  appear  that 
much  of  the  nitrogen  was  escaping  to  the  atmosphere  in  the  form  of  ammonia. 

The  following  analysis  of  the  poudrette  produced  at  Montfaucon,  a  suburb  of 
Paris,  as  well  as  at  works  at  New  York,  Hartford,  Dresden  and  Cologne,  show  the  ap- 
proximate value  of  the  product.  The  ingredients  varied  considerably  at  different 
times  and  among  the  works  in  the  different  cities. 


TABLE  LVI 
Composition  of  Poudrette  feom  Various  Sources 


Water 

Organic 
Matter 

Total 
Nitrogen 

Ammonia 

Nitric 
Acid 

Phosphoric 
Acid 

Lime 

Montfaucon: 

Boussingault  and  Payen  

1.41 

1.56 

Jaquemont  

1.90 

Soubeiran  (1S47)  

28-32 

29.00 

1.78 

0.73 

3.73 

L'Hote  (1848)  

30.20 

32.81 

1.52 

0.59 

0.30 

4.18 

6.70 

N.  Y.  City,  Lodi  Mfg.  Co.  (reported  by  J 
S.  W.  Johnson)  1 

32.52 
15.60 
25.62 

14.88 
18.40 
14.80 

0.95 
0.98 
0.95 

1.06 

1.05 

Hartford,  Conn.  (S.  W.  Johnson)  

39.97 

20.57 

1.01 

0.87 

Dresden : 

(Muller)  

19.50 

20.80 

2.10 

2.50 

2.70 

(Scheven)  

18.42 

11.25 

1.34 

(Bretschneider)  

15.91 

35.12 

1.68 

2.75 

Cologne  (Grouven)  

12.80 

36.20 

2.01 

3.01 

Compost.  By  composting  is  meant  the  systematic  mixing  together  of  various  fer- 
mentable waste  substances  in  a  heap  and  permitting  a  sufficient  interval  of  time  to 
pass  for  the  fermentation  of  the  mass.  Composting  is  a  common  practice  in  German 
and  Dutch  cities  and  in  view  of  the  value  of  the  product  obtained,  the  ease  of  prepar- 
ation and  the  completeness  with  which  all  necessary  sanitary  requirements  are  com- 
plied with,  it  is  surprising  that  more  use  has  not  been  made  of  this  principle  elsewhere. 

It  is  true  that  composting  is  widely  practiced  in  America,  but  it  is  employed  for 
another  purpose.  Farmyard  manure  which  is  allowed  to  rot  is  composted.  But  the 
method  which  is  generally  employed  in  the  United  States  is  wasteful  in  the  extreme 
and  is  usually  carried  on  with  a  poor  idea  of  the  underlying  principles  upon  which 
the  best  results  may  be  procured. 

The  city  composts  which  are  prepared  on  the  continent  of  Europe  are  generally 
mixtures  of  street  sweepings,  garbage  and  other  refuse  with  some  excrement  and 
enough  moisture  to  insure  satisfactory  fermentation.    In  the  central  depot  for  the 


366        DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

disposal  of  the  city  wastes  of  Amsterdam,  the  compost  heaps  are  arranged  in  an  orderly 
manner,  provided  with  suitable  drainage  and  built  up  and  removed  with  a  degree  of 
skill  which  is  the  result  of  long  experience. 


The  English,  who  were  among  the  first  to  apply  sewage  to  land,  first  with  the  object 
of  disposing  of  the  sewage  and  second  with  the  intention  of  gaining  a  profit  from  the 
utilization  of  the  manurial  ingredients,  divided  the  methods  of  application  into  three 
classes  according  to  (a)  the  presence  or  (b)  the  absence  of  underdrainage  and  (c) 
combination  with  chemical  or  other  preliminary  treatment. 

The  oldest  method,  called  broad  irrigation,  does  not  employ  underdrainage.  Its 
efficiency  depends  upon  the  purifying  action  which  takes  place  near  the  surface  of 
the  soil.  In  preparing  the  land,  shallow  ditches  are  dug  approximately  following  the 
contours  of  the  ground  and  tending  toward  slightly  lower  places  where  that  part  of 
the  sewage  which  does  not  soak  into  the  soil  at  first  may  be  collected. 

Irrigation  was  practiced  in  Europe  prior  to  the  year  1400,  but  the  earliest  use  of 
sewage  in  this  way  was  at  Bunzau,  Prussia,  in  1559,  where  about  35  acres  of  privately 
owned  land  were  irrigated  for  over  300  years.  The  Craigentinny  Meadows,  near 
Edinburg,  have  received  sewage  for  some  200  years.  Between  1860  and  1880  the  de- 
velopment of  sewage  farming  in  England  was  rapid.  On  the  continent,  Paris  adopted 
this  method  in  1865,  Dantzic  in  1869  and  Berlin  in  1876.  By  1883  there  were  over  200 
sewage  farms  in  Great  Britain. 

In  1868  a  Royal  Commission  announced  that :  "Irrigation  is  the  only  process  of 
cleansing  sewage  which  has  stood  the  test  of  experience."  But  from  that  time  it  was 
gradually  displaced  by  chemical  precipitation  processes. 

In  the  United  States  there  were,  in  1910,  about  103  small  plants  employing  sand 
filtration,  a  few  of  which  cultivated  crops  incidentally.  Many  of  these  were  in  Massa- 
chusetts, where  cropping  is  becoming  less  frequent.  Aside  from  these,  there  were  in 
the  year  mentioned  the  following  towns  employing  broad  irrigation: 


UTILIZATION  THROUGH  FARMING 


Arizona. . . 
California 


Kansas 


Massachusetts 


Tucson 
Fresno 
Hanford 
Pleasanton 


Humbolt 
Leicester 
Lenox 


Riverside 
Imperial 
Hiawatha 
Holton 


Massachusetts 


Ohio  

Pennsylvania 


Montana 


New  Jersey 


Michigan 


North  Brookfield 

Stockbridge 

Caro 

St.  Johns 

Red  Lodge 

Helena 

Pemberton 

Princeton 

Fostoria 

Altoona 


UTILIZATION  OF  SEWAGE  367 

Proper  Soils  for  Sewage 

A  great  deal  of  discussion  has  taken  place  during  the  last  fifty  years  concerning 
sewage  farming,  especially  with  respect  to  certain  details.  The  result  has  been  to 
show  that  no  rules  can  safely  be  laid  down  which  are  strictly  applicable  to  all  soils 
and  all  situations. 

Soils  differ  in  their  capacity  for  absorbing  sewage  according  to  their  physical  and 
chemical  composition  as  well  as  to  the  biological  processes  which  they  can  readily 
support. 

Before  estimating  closely  upon  the  capacity  of  farm  land  for  sewage,  it  is  desir- 
able that  mechanical,  chemical  and  biological  analyses  of  it  should  be  made. 

The  composition  of  the  soils  of  sewage  farms  may  be  materially  altered  by  the 
improper  application  of  sewage.  Crude  sewage  is  capable  of  depositing  a  layer  of 
black,  decomposing  material  upon  the  surface  which  clogs  the  openings  between  the 
soil  particles  and  prevents  further  absorption  of  sewage  and  of  the  oxygen  necessary  for 
nitrification.  Land  thus  heavily  coated  with  sewage  deposits  often  produces  serious 
nuisance  from  odor  and  if  the  application  of  sewage  is  continued,  the  soil  becomes  use- 
less. Land  in  this  condition  is  said  to  be  "sewage  sick."  Where  large  quantities  of 
sewage  are  being  applied  to  land,  it  is  usually  necessary  to  open  up  the  soil  by  plow- 
ing.  On  some  sewage  farms  a  large  amount  of  hand  labor  is  required. 

The  best  soil  for  a  sewage  farm  is  of  light,  porous  consistency  overlying  gravel. 
The  level  of  the  ground  water  should  be  rather  low;  low  enough  to  permit  the  fields 
to  be  well  underdrained.  There  should  be  water  courses  nearby  of  sufficient  size  to 
carry  off,  without  harmful  consequences,  such  excess  of  sewage  as  it  may  from  time 
to  time  be  necessary  temporarily  to  discharge  without  thorough  purification.  The 
land  should  be  inexpensive  and  of  great  enough  extent  to  permit  the  sewage  to  be  ap- 
plied without  excessive  dosing.  It  is  an  advantage  when  the  farms  are  remote  from 
villages  and  other  thickly  inhabited  areas.  There  should  be  a  ready  market  for  the 
produce  yielded  by  the  farm. 

Unfortunately,  the  land  within  easy  reach  of  great  cities  is  usually  divided  into 
relatively  small  plots  and  held  by  many  owners.  It  is  rather  costly  and  any  odors 
produced  upon  it  are  likely  to  cause  a  nuisance  to  many  persons.  Every  great  city 
is,  in  fact,  surrounded  by  villages  and  towns  and  the  opportunities  for  sewage  dis- 
posal by  application  to  farm  land  are  likely  to  be  in  reverse  proportion  to  their  need. 
It  is  usually  necessary  to  go  a  long  distance  from  the  center  of  a  large  city  to  find 
a  district  which  is  sufficiently  rural  to  possess  ideal  conditions  for  sewage  disposal. 


368        DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

Capacity  of  Farm  Land 

The  quantity  of  sewage  which  can  be  applied  to  farm  land  depends  upon  so  many 
factors  that  no  exact  rule  can  be  applied  to  it. 

Table  LVII,  taken  from  the  Fifth  Report  of  the  Royal  Commission  on  Sewage  Dis- 
posal, gives  in  concise  form  the  quantity  of  sewage  which  may  properly  be  applied  to 
one  acre  of  land. 

TABLE  LVII 

Quantity  of  Sewage  Which  May  Be  Applied  to  Land 

Imperial  Gallons  Acres  per  Million 

Conditions                             Settled  Sewage  Imperial  Gallons 

per  Acre  Daily  Dry  Weather  Flow 

Good  soil  and  subsoil : 

Filtration  with  cropping                                        12,000  84 

Filtration  with  little  cropping                                 25,000  40 

Surface  irrigation  with  cropping                               7,000  145 

Heavy  soil  overlying  clay: 

Surface  irrigation  with  cropping   5,000  200 

Stiff  clayey  soil  overlying  dense  clay : 

Surface  irrigation  with  cropping   3,000  334 

Moore  and  Silcock  in  their  work  on  Sanitary  Engineering  (1909)  give  the  approx- 
imate volumes  and  populations  that  can  be  taken  care  of  by  an  acre  of  different  soils 
and  with  crude  and  settled  sewage,  as  shown  in  Table  LVIII. 

TABLE  LVIII 
Allowance  of  Land  for  Sewage  Treatment 


Crude  Sewage 


Imperial 
Gallons 


Population 


Settled  Sewage 


Imperial 
Gallons 


Population 


Light  sandy  loam  on  gravel  and  sand 

Sandy  loam  on  gravel  and  sand  

Peaty  soil  on  gravel  and  sand  

Sand  and  gravel  

Gravelly  loam  on  gravel  and  sand  

Loam  getting  more  clayey  

Heavy  loam  on  marl  

Clay  soil  on  clay  

Stiff  clay  soil  on  dense  clay  


15,000 
12,000 
10,000 
8,000 
6,000 
4,500 
3,000 
1,500 
1,000 


375 
300 
250 
200 
150 
125 
75 
50 
33 


20,000 
17,000 
13,500 
10,000 
8,000 
6,000 
5,000 
4,000 
3,000 


500 
400 
325 
250 
200 
150 
130 
120 
100 


The  figures  in  the  foregoing  table  are  based  on  an  assumed  daily  flow  of  40 
imperial  gallons  per  capita. 

Rideal  estimates  that  the  sewage  from  100  persons  can  be  treated  on  an  acre  of 
loamy  gravel  and  that  the  number  may  rise  to  500  under  rarely  favorable  circum- 
stances, while  with  stiff  clay  it  falls  to  25.  The  rates  commonly  used  in  England  vary 
from  2,000  Imperial  gallons  per  acre  per  day  at  Leamington  and  Wrexham  to  15,000 


UTILIZATION  OF  SEWAGE 


369 


gallons  at  Cheltenham.  In  Germany,  "with,  on  the  whole,  better  preparatory  treat- 
ment and  a  more  favorable  soil,  the  rates  in  general  use  range  from  2,000  gallons  per 
acre  per  day  at  Brunswick  to  7,000  at  Danzig,  and  probably  average  about  4,000." 

In  the  opinion  of  the  Royal  Commission  on  Sewage  Disposal,  quoted  by  Scoble  in 
his  book  on  Land  Treatment  of  Sewage,  the  maximum  limits  of  the  rate  of  application 
to  land  by  irrigation  are  as  shown  in  Table  LIX. 

TABLE  LIX 
Data  Relating  to  English  Sewage  Farms 


Name  of  Farm 


Nature  of 
Sewage 


Nature  of  Soil 
and  Subsoil 


Method  of 
Treatment 


~*  0 

°£ 

CO  l 

<  a 


a 
(-. 

2 -a  a 
<  C  § 

.  <—  a) 
m  o  £ 

5  >> 


U  O 
—    -  -  — 

_  1 —  1- 

— 


Observations 
(Condensed) 


Aldershot  Camp 
Altrincham .... 

Cambridge  

Croyden  (Bed- 
dmgton)  

Leicester  

South  Norwood 
Nottingham  

Rugby  


Domestic . .  . 
Domestic. .  . 

Mainly  domes- 
tic  

Domestic  

%  domestic,  \i 
trade  refuse . 

Domestic  

*  domestic,  f 
trade  refuse. 

Mainly  domes- 
tic  


Sand  

Peaty  soil  on  sand 
and  gravel . . 

Sandy  loam  on 
gravel  and  sand. 

Gravelly  loam  over 
gravel  and  sand. 

Stiff  clayey  soil  over 
dense  clay.  . 

Clay  soil  on  Lon- 
don clay  

Light,  sandy  loam 
and  gravel  on 
gravel  and  sand 

Heavy  loam  over 
stiff  clay  


Screening,  settling, 
land  filtration. . . 
Settling,  land  filtra- 
tion  


Screening,  settling, 
land  filtration. . . 

Screening,  part  sur- 
face irrigation  fil- 
tration   

Screening,  settling, 
surface  irrigation 
and  filtration. . . . 
Screening,  settling, 
surface  irrigation 
Screening,  land  fil- 
tration   


Screening  —  chemi- 
cal precipitation, 
settling,  surface 
irrigation  and  fil- 
tration   


120H 
35 

74 

420 

1,350 

152 
651 

35 


8,300 
23,000 

30,400 

9,500 

5,370 

4,000 
10,750 

8,500 


166 
514 

675 

238 

146 

138 
397 

171 


Strong  sewage,  ef- 
fluent fair. 
Effluent  would  be 
good  with  some- 
what less  volume. 
Effluents  good  but 
not    in  highest 
class. 
9,500  gals,  per  acre 
somewhat  too 
high. 
Too  large  volume 
for  best  results. 

Too  large  volume 

for  best  results. 
Effluent  uniformly 
of  high  quality. 

Volume  too  great 
for  highest  class 
effluent.  , 


The  quantity  of  sewage  which  can  be  applied  to  crops  during  rainy  weather  is 
very  small  and  the  difficulty  which  arises  from  this  fact  is  increased  because  the  vol- 
ume of  sewage  is  itself  augmented  by  the  rain.  If,  as  commonly  occurs,  there  is  no 
more  land  than  is  needed  for  the  ordinary  flow  of  sewage,  it  becomes  necessary  in 
stormy  weather  to  discharge  the  sewage  from  the  farm  in  an  incompletely  purified  con- 
dition or  treat  it  by  some  supplementary  process. 

In  America,  comparatively  little  can  be  done  in  sewage  farming  and  that  which 
has  been  accomplished  has  been  under  conditions  which  are  not  general.  The  sewage 
farms  have  all  been  small.  Consequently,  there  is  little  useful  data  available  from 
this  country.   On  the  Passadena  farm,  with  300  acres  under  irrigation,  the  volume  dis- 


370         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

posed  of  per  acre  daily  was  about  2,800  gallons.  On  the  intermittent  filtration  area  at 
Framinghani,  Mass.,  crops  were  formerly  grown  with  a  rate  of  about  40,000  gallons  per 
acre  per  day.    This  was  with  comparatively  weak,  screened  sewage. 

Method  of  Applying  the  Sewage  to  the  Land 

The  methods  of  applying  sewage  to  the  land  vary  considerably.  The  simplest  plan 
is  to  allow  the  sewage  to  flow  over  the  surface,  the  sewage  being  conducted  to  the 
fields  by  ditches  and  the  effluent  being  carried  away  by  open  drains.  The  farms  are 
usually  so  arranged  that  where  passage  across  one  field  fails  to  purify  the  sewage  suf- 
ficiently, the  sewage  can  be  conducted  over  other  fields  located  at  lower  levels.  This 
kind  of  sewage  irrigation  is  most  suited  to  clayey  and  peaty  soils  which  do  not  readily 
permit  the  sewage  to  pass  through.  Some  authorities  consider  that  soils  of  this  kind 
are  not  suitable  for  sewage  farming  and  should  not  be  used  for  this  purpose.  In  Ger- 
many, it  is  customary  to  make  careful  study  of  the  soil  which  is  available  before  decid- 
ing upon  a  sewage  farm  and  only  in  those  cases  where  soil  of  proper  character  can 
be  obtained  is  it  considered  permissible  to  lay  out  a  sewage  farm.  In  England  the 
custom  of  restricting  sewage  farms  to  those  soils  which  are  suitable  has  not  always 
been  followed,  and  farms  have  often  been  laid  out  on  very  unsuitable  soil.  In  some 
cases  it  was  impossible  to  find  proper  soils  and  the  insistence  of  the  Government  upon 
the  application  of  sewage  to  land  made  it  necessary  to  use  such  soils  as  were  available. 

The  purification  effected  by  allowing  sewage  to  flow  over  the  surface  of  the  land 
is  relatively  slight  and  uncertain.  This  is  the  crudest  method  of  applying  sewage  to 
farm  land.  Where  suitable  soil  exists,  it  is  desirable  to  construct  underdrains  so  that 
the  sewage  can  pass  through  the  soil  and  so  undergo  the  purification  which  can  best 
be  carried  on  in  the  ground.  The  underdrains  are  arranged  in  various  ways  accord- 
ing to  local  circumstances  and  the  personal  opinions  of  those  who  happen  to  be  in 
charge  of  the  work;  no  exact  rules  being  followed.  The  underdrains  may  lie  from  3 
to  6  feet  beneath  the  surface  and  they  may  be  from  30  to  50  feet  apart.  Their  slope  is 
generally  about  1  in  200. 

Ridges  and  Furroivs.  The  sewage  is  conveyed  to  the  field  in  open  ditches  and  may 
be  spread  over  the  soil  evenly  or  in  furrows.  Where  furrows  are  employed,  it  is  cus- 
tomary to  dig  them  between  the  lines  of  underdrains  so  that  the  sewage  may  pass  as 
far  as  practicable  through  the  soil.  The  crops  are  sown  on  the  ridges  between  the 
furrows. 

The  ridge  and  furrow  system  has  many  advantages.  Among  them  is  the  oppor- 
tunity afforded  for  applying  the  sewage  to  the  roots  without  fear  of  doing  harm  by 
wetting  the  leaves  and  upper  stems. 


UTILIZATION  OF  SEWAGE 


371 


The  sewage  is  always  applied  intermittently.  The  frequency  and  duration  of 
dosing  varies  considerably.  The  sewage  may  be  run  upon  the  land  for  a  period  of  24 
hours  at  intervals  of  every  four  or  five  days  or  it  may  be  applied  during  a  longer 
period  with  a  shorter  interval  of  rest.  As  a  general  rule,  it  is  customary  to  allow 
from  2  to  4  times  as  long  a  period  between  applications  as  is  allowed  for  the  applica- 
tion itself. 

Preliminary  Treatment.  It  not  infrequently  occurs  that  sewage  has  to  be  treated 
by  some  process  before  it  is  applied  to  land.  If  the  large  solids  are  not  removed,  the 
land  may  become  not  only  covered  with  black,  slimy  deposit,  but  worse,  a  fetid  mat 
of  solids  may  accumulate  in  the  pores  and  on  the  surface  of  the  soil  which  greatly 
retards  the  penetration  of  the  liquid  sewage. 

In  some  cases  it  is  desirable  to  remove  the  grease  from  the  sewage  before  applying 
it  to  the  land.  The  total  quantity  of  grease  produced  in  some  cities  where  manufac- 
turing processes  are  carried  on  is  very  great.  Studies  made  at  Berlin  indicate,  ac- 
cording to  Dunbar,  that  about  20  grams  of  grease  are  produced  per  capita  per  day. 
This  is  sufficient  to  spread  one-half  a  gram  of  grease  over  each  square  yard  of  the  land 
at  the  sewage  farms  per  annum.  Grease  is  of  no  use  whatever  in  agriculture;  it  is 
harmful  to  the  sewage  farm. 

If  sewage  has  to  be  treated  for  the  removal  of  its  solid  matters  and  grease  before 
the  sewage  is  applied  to  the  land,  the  cost  of  sewage  farming  is  increased. 

The  Interests  of  Sanitation  and  op  Agriculture  Opposed 
The  interests  of  sanitation  and  of  agriculture  are  frequently  opposed  in  sewage 
farming.  It  is  of  sanitary  advantage  to  apply  the  sewage  in  such  way  as  will  produce 
the  highest  degree  of  purification  and  this  must  be  done  regularly  and  with  little  or  no 
odor  or  other  nuisance.  The  sewage  must  be  disposed  of  promptly  and  at  the  rate  at 
which  it  is  produced.  It  should  not  require  expensive  preliminary  treatment  in  order 
to  fit  it  for  absorption  by  the  soil.  The  state  of  the  weather  should  produce  no  injuri- 
ous effect  upon  the  process  of  disposition.  The  increase  in  volume  produced  by  the 
growth  of  population  should  not  require  expensive  additions  to  the  works.  There  should 
be  no  danger  of  injury  to  health.  Extensive  harm  to  property  in  the  vicinity  of  the 
works  should  not  result.  The  interests  of  agriculture  require  that  the  sewage  be  ap- 
plied only  when  needed  and  in  such  quantity  only  as  to  satisfy  the  needs  of  the  growing 
plants.   In  winter  and  in  heavy  storms  no  sewage  is  wanted. 

Factors  Affecting  Results  Obtained  by  Sewage  Irrigation 

Climate.  Climate  is  an  important  factor  in  determining  the  suitability  of  sew- 
age farming.  Where  the  atmosphere  is  humid  or  the  rainfall  abundant,  less  sewage 
can  be  taken  up  by  vegetation  than  in  the  arid  regions.     With  heavy  downpours, 


372         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

special  provision  is  required  in  the  way  of  equalizing  basins  or  filters.  Arid  regions, 
such  as  those  of  India,  Egypt  and  our  own  West  are  particularly  favorable  for  the 
reception  of  sewage  for  irrigation.  Cold  climates,  on  the  contrary,  are  not  so  suitable. 
When  led  onto  the  fields  in  furrows,  sewpge  does  not  freeze  except  during  very  low 
temperatures  provided  the  supply  of  sewage  is  nearly  continuous,  but  it  is,  of  course, 
not  usefully  employed  under  these  conditions. 

Sanitary  Considerations.  Although  slight  odors  may  be  carried  for  some  distance 
during  certain  atmospheric  conditions,  there  is  no  evidence  that  sewage  farms  are 
detrimental  to  health.  This  is  the  experience  on  the  farms  of  Berlin  on  which  over 
4,000  persons  reside  on  39,000  acres,  and  is  the  conclusion  reached  by  the  Royal  Com- 
mission on  Sewage  Disposal. 

Crops  to  be  eaten  raw  should  not  be  dosed  with  sewage  before  gathering  and,  in 
fact,  the  experts  of  the  Royal  Commission  on  Sewage  Disposal,  Messrs.  McGowan, 
Houston  and  Kershaw,  would  even  go  so  far  as  to  limit  sewage  farms  to  the  raising 
of  food  for  cattle,  but  this  seems  an  unnecessary  restriction.  Waring,  in  his  "Modern 
Methods  of  Sewage  Disposal,"  says  that  "after  all  these  years  of  experience,  it  may 
be  stated  in  the  most  positive  manner  that  there  is  no  sanitary  objection  whatever  to 
the  system  of  sewage  disposal  by  agricultural  irrigation." 

There  remains  to  consider  the  possible  pollution  of  water  supplies.  If  the  land 
is  underlaid  by  limestone,  chalk  or  seamy  rock  or  beds  of  coarse  gravel  from  which 
supplies  are  taken,  there  is  danger  of  contamination ;  but  if  the  soil  is  fine  and  homo- 
geneous, the  effluent  may  be  able  to  satisfy  the  standards  of  a  drinking  water  on  a 
well  operated  farm. 

The  location  of  the  farm  with  reference  to  the  city  is  important,  first,  in  its  effect 
on  the  price  of  land,  and  consequently  the  cost  of  the  farm,  and  second,  in  its  prox- 
imity to  a  market  for  the  products.  The  distance  of  the  farm  from  the  city  affects 
the  character  of  the  sewage,  for  sewage  becomes  offensive  with  long  carriage. 

Sociological  Conditions.  Sociological  conditions  are  so  different  in  Europe  and 
America  that  it  is  unsafe  to  infer  from  foreign  experience  what  might  be  accomplished 
in  the  United  States  in  this  respect.  If  the  farm  and  the  condition  of  the  effluent  are 
to  be  entirely  under  the  control  of  the  municipality,  a  large  body  of  employes  must  be 
added  to  those  already  on  the  city's  pay-roll.  Where  the  control  is  by  an  intelligent 
and  strong  centralized  government,  as  in  Germany,  there  is  relatively  little  objection 
from  this  standpoint. 

Greater  efficiency  in  operation  might  be  secured  by  a  private  corporation  than  by 
a  city,  but  the  principle  of  relegating  the  function  of  purifying  sewage  and  operat- 
ing a  productive  farm  to  any  but  a  public  authority  is  not  wise,  as  the  profits  to  be 


UTILIZATION  OF  SEWAGE  373 

derived  from  the  sale  of  crops  would  be  pushed,  to  the  probable  neglect  of  the  sanitary 
considerations. 

Crops 

With  the  exception  of  cereals  and  legumes  the  crops  best  adapted  to  sewage 
farming  are  those  which  it  is  found  most  profitable  to  raise  on  other  farms  in  the 
neighborhood,  provided  they  have  a  large  capacity  for  taking  up  water.  Italian  rye 
grass  has  been  found  one  of  the  best  crops  to  raise,  and  cabbages,  kale,  mangolds, 
beets,  turnips,  carrots,  onions,  potatoes  and  celery  thrive  well.  In  England,  osiers 
have  been  found  to  grow  well  in  wet  irrigated  soils  and  at  Sutton  the  raising  of  mint 
for  oil  was  found  profitable.  Cabbage  is  said  to  be  injured  in  flavor  by  sewage  and  it 
should  not  be  applied  to  lettuce,  berries  or  other  farm  products  which  are  to  be  eaten 
raw. 

It  is  often  profitable  to  devote  a  part  of  the  land  to  pasturage.  In  this  way  the 
crops  are,  at  least  in  part,  disposed  of  without  cost  for  transportation  and,  if  produced 
in  excess,  can  be  stored  by  ensilage  for  future  use.  Cows  and  horses  are  an  important 
source  of  revenue  on  the  Reading,  Nottingham,  Aldershot  and  other  farms  in  Eng- 
land and  the  sale  of  wool  from  sheep  constitutes  a  principal  source  of  revenue  on 
the  Melbourne  farm.  Where  cows  are  raised,  milk  is  a  valuable  product.  The  proper 
management  of  a  large  sewage  farm  therefore  requires  in  the  manager  a  man  of  un- 
usual qualifications  pertaining  to  irrigation,  farming,  stock  raising  and  the  dairy 
business. 

Nuisances  from  Odors 

Sewage  farms  not  infrequently  give  rise  to  considerable  nuisance  from  odors. 
This  is  particularly  true  where  the  extent  of  land  is  insufficient  to  take  care  of  all 
the  sewage  which  needs  to  be  disposed  of.  At  best  the  exposure  of  sewage  through 
several  miles  of  open  ditches  is  not  an  agreeable  procedure  when  regarded  from  the 
aesthetic  standpoint.  It  is  true  that  in  some  cases,  notably  at  the  sewage  farms  of 
Berlin,  hospitals,  convalescent  homes  and  even  playgrounds  for  children  have  been 
arranged  at  no  great  distance  from  the  sewage  fields;  but  in  those  cases  where  high 
sanitary  standards  exist,  the  advantages  to  agriculture  are  considered  of  distinctly 
secondary  importance  and  the  success  of  the  process,  as  reckoned  from  the  business 
standpoint,  is  generally  poor. 

The  secret  of  successful  application  of  sewage  to  the  growing  of  crops  lies  in  hav- 
ing a  good  soil  to  work  with,  providing  scientific  management  and  in  having  an 
abundant  area  of  land.  The  crops  should  be  given  sewage  only  when  they  want  it. 
Saturation  of  the  soil,  known  as  sewage  sickness,  should  never  occur.    There  should 


374         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

always  be  reserve  areas  to  take  up  the  excess  volume  which  frequently  occurs.  The 
land  in  the  vicinity  should  not  be  of  such  great  value  as  to  prevent  extensions  being 
made  to  the  works  which  the  increasing  quantities  of  sewage  from  growing  popula- 
tions require.  Nor  should  the  works  be  situated  so  close  to  villages  and  towns  as  to 
cause  the  latter  to  suffer  seriously  from  the  odors  to  which  the  sewage  fields  may  give 
rise. 

It  should  not  be  necessary  to  produce  an  effluent  of  the  highest  chemical  and  bac- 
terial purity.  Sewage  farming  is  capable  of  producing  an  effluent  which  is  as  clear 
and  clean  as  any  process  of  sewage  treatment  can  yield,  but  this  result  can  be  achieved 
only  under  favorable  circumstances.  It  has  frequently  been  remarked  by  impartial  ex- 
perts that  in  very  few  places  are  rigid  sanitary  requirements  fulfilled  by  sewage 
farms.  In  numerous  instances,  it  has  been  necessary  to  abandon  farms  in  order  to 
obtain  a  disposition  of  the  sewage  which  would  be  satisfactory  from  the  sanitary 
standpoint. 

Examples  of  Sewage  Farms 

PARIS 

TABLE  LX 

Data  Relating  to  the  Sewage  Farms 

Population,  1910   2,800,000 

Population,  per  acre   221 

Ordinary  volume  of  sewage  per  day   160  to  185  million  gallons 

Ordinary  sewage  per  head  per  day   57 . 1  to  64 .8  gallons 


Farm 

Areas  of  Farms  in  Acres 

Total 

Privately 
Owned 

Owned  by 
Municipality 

1,996 
386 
3,731 
2,137 

15 
2,965 
1,235 
210 

2,011 
3,351 
4,966 
2,347 

Mery-Pierrelaye  

8,250 

4,425 

12,675 

The  soil  is  largely  a  sandy  alluvial  deposit  with  some  gravel  and  some  clay  down 
to  a  depth  of  from  6  to  20  feet.  It  is  partially  underdrained  at  13  feet.  The  sewage 
before  delivery  to  the  farms  has  passed  through  a  grit  chamber  and  screen. 

From  Table  LX  the  average  amount  of  sewage  applied  per  acre  per  day  is  seen 
to  be  about  13,600  gallons,  although  the  volume  received  at  Gennevilliers  is  restricted 
by  law  to  11,800  gallons  per  acre  daily.  Experiments  have  shown  that  in  raising 
lucerne  the  land  will  take  42,700  gallons  and  that  meadow  land  will  take  49,300  gal- 
lons per  acre  daily  without  prejudice  to  the  crops  or  effluent.    At  Gennevilliers  there 


UTILIZATION  OF  SEWAGE 


375 


is  a  "model  garden"  where  various  fruits,  flowers,  vegetables  and  shrubs  are  grown  and 
it  has  been  shown  that  this  will  take  from  23,000  to  37,000  gallons  per  acre  per  day. 

On  the  lands  owned  by  the  city,  sewage  is  taken  by  the  tenant  in  fixed  amounts 
and  its  use  is  under  the  supervision  of  the  city  but  in  the  larger  area  privately  owned, 
it  is  taken  or  rejected  at  the  option  of  the  farmer.  There  is  much  that  finds  its  way 
to  the  Seine  without  treatment  during  storms.  The  sewage  used  in  irrigation  is  dis- 
charged to  the  river  in  a  well  purified  condition. 

The  cost  of  the  farms  up  to  1900  was  $7,220,000  and  the  annual  operating  expenses 
were  about  one  million  dollars.  The  Gennevilliers  crop  was  worth  about  $200  an 
acre  or  $400,000  in  1907.    Data  for  the  other  farms  are  lacking. 

It  is  a  significant  fact  that  the  city  has  been  carrying  on  experiments  with  more 
intensive  methods  of  sewage  treatment  for  some  years. 

BERLIN 

TABLE  LXI 
Data  Relating  to  the  Sewage  Farms 

Population  in  1910   2,064,153 

Sewage  treated  per  day   77  million  gallons 

Sewage,  per  capita,  daily   37  gallons 


Area  of  Farms  in  Acres 

Total 

Farmed  by 
City 

Leased  to 
Market 
Gardeners 

Unproductive 

Total  

16,657 
10,647 

3,956 
2,486 

395 
8,868 

21,008 
22,001 

27,304 

6,442 

9,263 

43,009 

At  the  end  of  1910  there  were  the  areas  of  prepared  land  as  shown  in  Table  LXII. 

TABLE  LXII 
Areas  of  Prepared  Land 


Used  for  broad  irrigation   7,994  acres 

Used  for  filtration  bed   12,250  " 

Used  for  settling  basins   502  " 

Roads  and  miscellaneous   2,105  " 


Total   22,851 


The  soil  is  light  and  sandy.  The  beds  are  about  150  to  200  feet  square  and  are 
underdrained  at  a  depth  of  from  4  to  6  feet  by  lines  of  tile  16  to  30  feet  apart.  The 
grit  and  heavier  sludge  and  fats  are  removed  before  applying  the  sewage  to  the  land. 


376         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


The  rate  of  filtration  is  about  3,700  gallons  per  acre  of  prepared  land.  There  are 
48  inhabitants  per  acre  of  farm  or  about  98  per  acre  of  land  under  irrigation. 

The  principal  crops  raised  are  rye  grass,  turnips,  beets,  cabbages,  potatoes  and 
grain.  About  a  quarter  of  the  area  operated  by  the  city  is  pasturage.  There  are  40 
acres  of  fish  ponds  which  yield  about  $80  worth  of  fish,  mostly  carp,  per  acre  per  year. 

The  total  cost  of  the  farms  to  March  31,  1910,  was  $17,470,000.  The  cost  per  acre 
was  as  shown  in  Table  LXIII. 

TABLE  LXIII 
Cost  of  the  Sewage  Farms 

Total  Area       Land  Specially 
Prepared 

Purchase  of  land   $229 . 38  $43 1 . 52 

Preparation  of  land   131.40  247.80 

Buildings  and  miscellaneous   45.42  85.26 

Total  expenses   $406 . 20  $764 . 58 

The  receipts  and  expenses  of  operation  in  1910  were  as  shown  in  Table  LXIV. 

TABLE  LXIV 

Running  Expenses  op  the  Sewage  Farms 

Receipts   $1,240,772.58 

Increase  in  value  of  live  and  dead  stock   122,593 .50 

  $1,363,366.08 

Maintenance   $1,300,385.34 

Payment  of  interest  and  loans   741,817 .62 

  741,817.62 

Deficit   $678,737.88 

From  the  foregoing  figures  there  is  seen  to  be  a  decided  loss  when  the  fixed  charges 
on  capital  invested  are  included. 

The  Berlin  farms  are  the  most  extensive  and  perhaps  the  best  managed  in  the 
world.  They  are  under  the  control  of  the  authorities,  are  on  land  admirably  adapted 
to  the  purpose,  convenient  to  the  markets  and  employing  in  part  convict  labor  at  low 
cost.  Yet,  largely  on  account  of  the  increasing  value  of  the  land,  it  is  Dr.  Dunbar's 
opinion  "that  many  of  us  will  live  to  see  the  day  when  Berlin  will  sell  its  irrigation 
farms  for  building  purposes  and  construct  artificial  biological  works  in  their  place. 

NOTTINGHAM 
TABLE  LXV 
Data  Relating  to  the  Sewage  Farm 

Population  drained  to  sewers  in  1910   258,584 

Population  per  acre  irrigated   397 

Mean  dry  weather  flow   8,400,000  gallons  per  day 

Sewage  per  head  per  day   32  gallons 

Area  of  farm   907  acres 

Irrigable  area   651  " 

Area  irrigated  at  one  time   300  " 

Gallons  of  sewage  treated  per  acre  irrigated  per  day   28,000  gallons 

Gallons  of  sewage  treated  per  acre  of  farm  per  day   12,900  " 


UTILIZATION  OF  SEWAGE  377 

Baker  says  in  his  "British  Sewage  Works"  that,  when  visited  by  him,  in  1904, 
the  dry  weather  flow  had  increased  to  10.8  million  gallons  per  day  and  the  total  area 
of  the  farm  was  1,950  acres,  of  which  1,300  acres  were  irrigable.  About  120  acres  of  this 
were  held  in  reserve  for  emergency  use. 

The  first  636  acres  were  leased  in  1878  at  $21.30  per  acre  annually  for  65  years. 
Since  then  all  but  173  acres  of  the  holdings  in  1901  had  been  bought  by  the  city  at  an 
average  gross  cost  of  $583  per  acre.    The  farm  was  first  operated  in  1880. 

The  combined  system  of  sewerage  is  used.  About  3/7  of  the  flow  is  trade  waste 
from  bleaching,  dye  and  wool  scouring  works,  breweries,  etc.,  but  the  amount  of  solid 
excreta  is  not  large  owing  to  the  fact  that  many  of  the  dwellings  are  not  connected 
with  sewers.  Storm  water  is  admitted  to  the  sewers  up  to  a  rate  of  14-inch  of  rain- 
fall per  day. 

The  soil  is  generally  of  light  sandy  loam,  7  inches  to  15  inches  thick,  overlying 
and  interspersed  with  gravel  and  sand.  This  is  all  underdrained  at  a  depth  of  from 
4%  to  7y2  feet. 

About  half  the  irrigable  area  is  irrigated  at  one  time  and  some  50  acres  of  this, 
closely  underdrained,  is  in  continuous  operation  for  a  month  or  so,  until  overdosed. 
The  balance  is  divided  into  two  parts,  each  of  which  receives  sewage  12  hours  in  al- 
ternation with  the  other. 

The  staple  crops  are  Italian  rye  grass,  mangel-wurtzel,  ox  cabbage,  kale  and  kohl- 
rabi, but  during  years  when  not  irrigated  there  are  grown  clover,  cabbage,  grain, 
potatoes  and  turnips. 

There  are  also  kept  620  head  of  cattle,  including  92  milch  cows,  620  sheep,  320 
swine  and  130  horses. 

The  gross  revenue  is  about  $78,000,  of  which  about  $11,000  is  from  the  sale  of 
milk. 

The  force  required  to  work  the  farm  comprises  110  men  and  boys  whose  wages 
amount  to  $19,400  per  annum.  The  boys  start  in  at  $1.46.  The  wages  shown  in  Table 
LXVI  are  paid  per  week  in  addition  to  the  use  of  a  house  and  garden  : 

TABLE  LXVI 
Wages  Paid  on  the  Sewage  Farms 

Foreman  Labor 

Ordinary  work                                                                       $6 . 32  $4.13 

Milkers                                                                                  6.32  4.62 

Wagoners                                                                           7.29  4.86 

Engineers  (for  agricultural  machines)                                            9.72  6.07 

For  the  first  22  or  23  years  of  operation  there  was  always  a  revenue  over  and 
above  operating  costs  amounting  to  over  $12.00  per  acre  but  the  next  year  being  un- 


378 


DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


usually  wet  there  was  a  loss.  The  favorable  showing  appears  to  be  due  mainly  to  the 
excellent  condition  of  the  soil  and  to  the  especially  efficient  superintendence  of  the 
farm. 

PASSADBNA 

In  the  United  States  the  Passadena  farm  has  been  perhaps  the  most  profitable. 
Tbree  hundred  acres  were  bought  in  1887  for  $40,000  and  150  acres  more  in  1904  for 
$9,000.  In  the  year  1903-4,  840,000  gallons  were  received  on  the  land  which  was 
planted  with  alfalfa  and  walnuts.  Later,  alfalfa  was  given  up  as  unsuitable.  The 
operating  expenses  were  $6,310.91  and  the  revenue  $11,643.57  ($7,847.29  of  which  was 
from  the  sale  of  walnuts).  Even  with  $1,400  added  to  the  expense  account,  for  inter- 
est at  3!/2  per  cent.,  there  remained  a  profit  of  over  $3,900,  or  about  $13  per  acre.  In 
spite  of  this  apparent  profit,  the  farm  has  now  been  abandoned  for  other  means  of 
disposal. 

American  and  European  Conditions  Compared 

There  are  many  reasons  why  sewage  farming  is  not  so  well  adapted  to  American 
as  to  European  conditions.  In  the  first  place,  the  water  consumption  per  capita  being 
twice  that  of  European  cities,  the  land  required  under  conditions  otherwise  similar  is 
also  twice  as  great  and  so  twice  as  costly.  The  price  of  labor,  too,  is  much  higher  in 
America  than  abroad,  and  as  about  twice  as  many  men  are  required  per  acre  as  on  an 
ordinary  farm ;  this  places  sewage  farms  in  America  at  a  disadvantage.  Finally,  polit- 
ical conditions  are  less  favorable  here.  For  successful  farming  and  to  secure  sanitary 
results,  the  city  should  control  the  application  of  the  sewage.  The  Royal  Commission 
on  Sewage  Disposal  has  placed  itself  on  record  as  against  the  practice  of  losing  con- 
trol by  leasing  farms  devoted  to  sewage  irrigation.  This  means  municipal  operation, 
often  on  a  large  scale,  with  all  the  uncertainties  connected  with  the  changing  and 
decentralized  administration  of  our  American  cities  and  the  opposition  of  those  with 
whom  the  sale  of  the  products  would  bring  the  city  into  commercial  competition. 

It  is  important  that  the  peculiar  difficulties  to  be  met  should  be  fully  appreciated 
before  committing  a  town  to  the  adoption  of  sewage  farming.  They  include  (1)  the 
cost  of  land  near  cities  and  its  equipment  (which  has  been  estimated  at  five  times  that 
of  an  ordinary  form),  (2)  the  character  of  the  land,  (3)  the  penetration  of  frost  in 
soils  otherwise  favorable,  (4)  the  removal  and  disposal  of  the  coarse  solids,  (5)  the 
possibility  of  unpurified  sewage  finding  its  way  to  a  water  supply,  (6)  the  possible 
infection  of  cattle  feeding  on  sewaged  grass,  (7)  the  possibility  of  odors  permeating 
the  atmosphere  in  warm,  damp  weather,  (8)  the  problem  of  procuring  adequate  and 
efficient  superintendence  and  labor,  (9)  transportation  and  sale  of  crops. 


UTILIZATION  OF  SEWAGE 


379 


Financial  Results 

Among  the  most  complete  financial  figures  are  those  given  by  the  Royal  Com- 
mission on  Sewage  Disposal  in  their  Fifth  Report.  These  are  based  on  a  million 
imperial  gallons  of  "normal  domestic"  sewage  per  day  from  25,000  persons  on  land  at 
$484  per  acre  and  labor  at  $5.11  per  week.  It  is  assumed  that  the  sewage  is  collected 
by  the  combined  or  partially  separate  system  and  the  last  includes  preliminary  sedi- 
mentation and  the  disposal  of  sludge  as  well  as  the  cultivation  of  the  farm. 

The  areas  required  under  different  conditions,  gross  cost  and  receipts  are  given 
in  Table  LXVII  from  the  Fifth  Report  of  the  Royal  Commission. 


TABLE  LXVII 

Data}  Cost  and  Returns  from  Sewage  Farms  in  England 


Nature  of  Soil 


Sandy  loam  overlying 

gravel  and  sand . 
Sandy  loam  overlying 

gravel  and  sand . 
Sandy  loam  overlying 

gravel  and  sand . 
Heavy  soil  overlying 

clay  

Stiff  clayey  soil  over 

dense  clay  


Process 


Filtration  with  crop 

ping  

Filtration  with  little 

cropping  

Surface  irrigation  and 

cropping  

Surface  irrigation  and 

cropping  

Surface  irrigation  and 

cropping  


Gallons 
Settled 
Sewage 
per  Acre 
Daily 


14,400 
30,000 
8,400 
6,000 
3,600 


Total  Acres 
dwf.*  in 
Mgd.*' 


70 
33 
126 
167 
280 


Gross 
Cost  per 
Mgd.** 


$13.71 
10.02 
16.89 
24.34 
34.56 


Receipts 

per 
Mgd.** 


$1.38 
.65 
2.40 
3.30 
5.52 


Net  Cost 

per 
Mgd.** 


$12.33 
9.37 
14.49 
21.04 
29.04 


Cost  per 
Capita 


17.7c. 
13.7c. 
21.3c. 
30.9c. 
42.5c. 


*  Dwf.  =  dry  weather  flow.    **  Mgd.  =million  imperial  gallons  per  day. 

Under  the  conditions  assumed,  it  was  estimated  that  irrigation  would  be  cheaper 
than  tank  treatment  followed  by  percolating  filters  where  the  soil  was  light  and 
porous,  but  not  otherwise.  The  conditions  are  subject  to  wide  variation.  The  larger 
the  area,  the  greater  the  cost,  but,  with  good  management,  the  larger  the  area  the 
better  the  prospect  for  a  profit. 

In  the  21  towns  whose  returns  from  sewage  irrigation  are  enumerated  in  the 
table  just  given,  there  are  about  8  whose  income  exceeds  their  operating  expenses  and 
there  is  none  showing  a  net  profit  after  deducting  loan  charges.  This  does  not  mean 
that  many  of  these  farms  have  not  been  an  economically  wise  investment.  That  point 
can  only  be  decided  by  comparing  their  cost  with  the  cost  which  would  have  been 
incurred  for  disposal  by  other  methods. 

Analyses  thus  sets  at  rest  the  popular  notion  that  sewage  farming  is  profitable 
as  a  purely  business  venture.  As  stated  by  the  Royal  Commission,  quoted  by  Scoble 
in  his  work  on  "Land  Treatment  of  Sewage" :  "Although  we  are  of  opinion  that  sewage 


380        DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

farms  in  general  can  never  show  a  profit,  if  interest  on  capital  expenditure  is  in- 
cluded, the  fact  that  in  favorable  seasons  some  of  them  can  more  than  cover  the 
working  expenses  is  a  point  in  favor  of  cropping." 

Authoritative  Opinions  with  Regard  to  Irrigation 

It  is  a  notable  fact  that  of  all  the  authors  of  recent  treatises  on  sewage  disposal, 
not  one  is  favorable  to  irrigation  except  in  situations  where  unusual  opportunities  for 
this  kind  of  disposal  occur. 

Dunbar,  in  his  "Principles  of  Sewage  Treatment,"  London,  1908,  page  115,  says : 

"It  will  have  been  noted  that  the  results  of  irrigation  from  a  sanitary  point  of 
view  are  influenced  by  many  factors,  some  of  which  it  is  impossible  to  control  and  yet, 
in  spite  of  this,  irrigation  is  still  regarded  as  the  best  method  of  sewage  purification. 
Its  application  as  a  method  of  raising  crops  is  only  possible,  generally  speaking,  at 
the  expense  of  the  purification.  It  has,  however,  been  generally  recognized  that 
profits  cannot  be  obtained  from  sewage  irrigation.  Contrary  opinions,  which  are 
held  by  imaginative  persons,  but  not  supported  by  actual  observations  are  continually 
cropping  up  and  being  urged  with  the  ardor  of  prophets.  They  may,  however,  reason- 
ably be  neglected  here." 

Again,  page  109 : 

"More  recently  the  value  of  domestic  sewage  as  a  manure  has  been  usually  esti- 
mated at  four  to  five  shillings  per  head  per  annum.  Hence,  by  a  rational  use  of  its 
domestic  sewage,  a  town  of  100,000  inhabitants  might  reasonably  expect  an  income 
of  nearly  f 125,000  per  annum  from  its  sewage.  Even  without  taking  into  account  the 
preparation  of  the  land  and  the  cost  of  conveying  the  sewage,  but  simply  considering 
the  working  costs,  such  incomes  have  nowhere  been  obtained.  No  case  is  known 
which  shows  a  profit  from  irrigation,  when  subjected  to  a  strictly  commercial  in- 
vestigation." 

Rideal,  in  his  book  on  "Sewage  and  the  Bacterial  Purification  of  Sewage,"  says : 
"With  careful  management  the  sale  of  produce  from  a  sewage  farm  may  be  made  to 
yield  a  small  balance  over  working  expenses,  but  not  sufficient  to  repay  the  capital, 
which  is  estimated  to  be  about  five  times  that  required  for  an  ordinary  farm." 

"The  chief  objections  to  land  filtration  have  been  summarized  as  follows: 

"1.  Generally  the  worst  part  of  the  sewage — the  sludge — is  not  dealt  with  at  all. 

"2.  As  crops  are  usually  grown,  their  cultivation  is  often  considered,  by  those 
left  in  charge,  as  more  important  than  the  purification  of  the  sewage,  and  so  the 
latter  is  not  fully  treated  except  where  irrigation  is  of  advantage  to  the  crops. 


UTILIZATION  OF  SEWAGE  381 

"3.  Unless  the  land  receives  very  careful  attention,  a  bad  result  is  generally  pro- 
duced from  even  the  best  farm  and  it  is  difficult  for  anyone  but  a  highly  trained  man 
to  keep  the  works  under  proper  control. 

"4.  There  are  many  possibilities  whereby  land  which  has  been  laid  out  carefully 
may  fail,  even  with  careful  working,  such  as  the  cracking  of  the  land,  admitting 
crude  sewage  into  the  drains  without  filtration. 

"5.  Land  of  sufficient  quantity  or  quality,  and  at  a  reasonable  price,  is  often  un- 
attainable." 

In  their  work  on  "Sewage  Disposal,"  New  York,  1910,  p.  207  et  seq.,  Messrs.  Kin- 
nicutt,  Winslow  and  Pratt  say : 

"On  the  whole,  it  may  be  said  that  a  sewage  farm  under  the  best  conditions, 
may  yield  a  better  effluent  than  that  which  can  be  obtained  from  contact  beds  or  trick- 
ling filters.  Where  the  soil  is  heavy,  however,  the  results  of  irrigation  are  very  much 
inferior  to  those  which  can  be  attained  by  the  so-called  'artificial'  processes.  Fur- 
thermore, in  sewage  farming  there  is  always  a  tendency  to  the  by-passing  of  surplus 
sewage  at  times  of  rain,  and  in  many  instances  this  militates  seriously  against  the 
general  eflieiency  of  the  process. 

"*  *  *  It  is  of  course  obvious  that  well  waters  in  the  neighborhood  of  irrigation 
areas  must  be  subject  to  strict  supervision  *  *  *. 

"The  economic  advantages  of  sewage  farming  have  long  been  a  debated  question. 
The  utilization  of  waste  products  is  always  an  attractive  idea ;  and  sewage  fields  cov- 
ered with  a  rich  mantle  of  luxuriant  vegetation  make  a  strong  appeal  to  the  imagina- 
tion. It  has  been  said,  however,  that  it  is  poor  economy  to  save  something  by  a 
process  which  costs  more  than  the  value  of  what  is  to  be  saved. 

"With  fair  soil  and  not  too  heavy  rainfall,  broad  irrigation  may  be  operated  satis- 
factorily by  cities  having  at  their  doors  large  areas  of  cheap  and  unfertile  sandy  soil. 
Its  economic  value  then  depends  upon  a  number  of  minor  variables.  The  cost  of  land, 
the  cost  of  labor,  the  available  markets  and,  above  all,  the  skilful  management  devoted 
to  the  farms  chiefly  control  the  final  result.*  *  *  Sewage  farming  is  not  likely  to  be 
one  of  the  future  activities  of  the  American  city  except  in  arid  regions." 

In  his  treatise  on  "Sewage  Disposal,"  New  York,  1912,  George  W.  Fuller  has 
said,  p.  595  et  seq. : 

"Strictly  speaking,  this  method  is  not  in  general  use  in  this  country  except  in 
the  Far  West,  although  there  are  some  intermittent  sand  filter  plants  in  the  East 
where  crops  are  raised  on  portion  of  the  area.  Some  profit  results  from  the  use  of 
these  filter  areas  for  agricultural  purposes,  but  this  seems  to  be  a  small  and  incidental 
feature  *  *  *. 


382        DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

"Many  references  in  technical  journals  can  be  found  to  the  use  in  the  West  of 
broad  irrigation  as  a  means  of  sewage  disposal.  But  the  facts  usually  show  that  such 
use  was  merely  incidental  and  not  entitled  to  serious  consideration  from  the  sanitary 
standpoint. 

««  #  «  when  the  sewage  is  not  considered  helpful  for  agricultural  uses,  there 
is  altogether  too  great  a  tendency  to  divert  it  to  some  neighboring  stream  bed.  This 
difficulty  has  been  regulated  properly  in  some  of  the  large  European  plants,  but  it 
requires  the  constant  and  careful  effort  of  a  competent  corps  of  inspectors  and  patrol- 
men. Otherwise  the  sanitary  requirements  as  to  sewage  disposal  become  entirely  sub- 
servient to  the  interest  and  convenience  of  the  farmer. 

"*  *  *  Objections  to  the  method  have  increased  rather  than  decreased  in  recent 
years.  These  relate  to  objectionable  odors,  prejudice  against  the  use  of  sewage  in 
growing  vegetables  and  to  the  transmission  of  disease  germs  by  flies  and  other  insects. 

"Experience  shows  that  only  nominal  aid  financially  has  been  received  from  the 
use  of  sewage  in  broad  irrigation." 

The  book  on  "British  Sewage  Works,"  New  York,  1904,  which  was  published  by 
M.  N.  Baker,  after  visits  to  the  principal  sewage  disposal  plants  of  Europe,  contains 
descriptions  of  various  sewage  farms  in  England  and  those  of  Paris.  Mr.  Baker,  after 
seeing  what  were  considered  to  be  the  best  managed  sewage  farms  in  Great  Britain, 
remarks,  page  104  et  seq. :  "For  some  years  past  nearly  all  the  printed  matter  relating 
to  sewage  disposal  in  Great  Britain  has  either  contained  no  reference  to  sewage  farms 
or  else  spoken  of  them  as  being  abandoned  as  rapidly  as  possible." 

On  page  114  Mr.  Baker  says:  "As  a  rule,  the  purely  natural  conditions  in  many 
sections  of  the  United  States  are  far  more  favorable  to  sewage  farming  than  they 
are  in  England,  but  nearly  all  other  conditions,  and  they  are  many,  are  against  the 
practice.  We  have  fortunately  never  been  carried  away  by  the  glowing  claims  of 
prophets  for  sewage  farming,  although  not  infrequently  they  are  urged  by  well  mean- 
ing but  ill-informed  persons." 

Among  the  foremost  scientific  authorities  who  have  considered  the  subject  of 
sewage  disposal  from  the  agricultural  standpoint  is  Prof.  F.  H.  Storer  of  Harvard 
University,  in  whose  book  on  "Agriculture  in  Some  of  Its  Relations  With  Chemistry," 
seventh  edition,  New  York,  1910,  is  an  extended  notice  of  this  subject. 

Barwise,  in  his  book  on  "The  Purification  of  Sewage"  (1899),  disclaims  any  real 
superiority  in  sewage  farming  as  a  means  of  conserving  the  fertilizing  ingredients. 
He  says :  "When  we  bear  in  mind  that  leguminous  plants  have  the  power  of  absorbing 
nitrogen  from  the  air  and  that  the  sea  requires  its  nitrogen  replenished,  on  account 


UTILIZATION  OF  SEWAGE  383 

of  the  fish  taken  from  it,  the  fallacy  of  the  uianurial-value  argument  becomes  too 
ridiculous  to  entertain  for  one  moment." 

An  adverse  opinion  of  its  value  is  that  of  Tidy  in  his  "Treatment  of  Sewage" 
(1887).  He  says:  "The  effect  of  all  the  constituents  of  a  manure  is  but  the  effect  of 
that  one  of  them  which,  in  comparison  with  the  wants  of  the  plant,  is  present  in  small- 
est quantity."  Therefore  artificial  fertilizers  are  usually  required  to  supplement  the 
deficient  potash  or  else  the  ammoniacal  and  phosphoric  acid  compounds,  which  are  in 
excess,  are  left  to  clog  the  soil.  Moreover,  while  the  crops  absorb  from  40  to  75  per 
cent,  of  the  nitrogen  from  the  ammonias  of  the  sewage,  weak  sewage,  such  as  are  often 
found  in  the  United  States,  may,  if  applied  in  excessive  amounts,  actually  remove  val- 
uable nianurial  salts  from  the  soil  by  solution. 

Another  person  has  said  that  it  would  be  as  reasonable  to  expect  farmers  to 
manure  their  land  with  the  smoke  of  cities  as  with  sewage,  for,  as  everyone  knows, 
enormous  quantities  of  ammonia  must  be  lost  in  the  aggregate  in  cities  where  domestic 
fires  are  fed  with  coal. 

Professor  Storer  considers  that  the  problem  of  how  to  dispose  of  the  sewage  of  a 
city  is  simply  a  sanitary  question.  The  danger  of  exhausting  the  fertility  of  the  soil 
by  continued  cropping  without  restoring  the  nitrogen  and  other  available  compounds 
by  means  of  manures  or  artificial  fertilizers  is  by  him  regarded  as  too  remote  for  con- 
sideration. If  the  laud  requires  enrichment,  the  use  of  artificial  fertilizers  is  capable 
of  supplying  all  that  will  be  needed.  The  present  sources  of  the  ingredients  of  fer- 
tilizers are  practically  inexhaustible  and  other  sources  will  doubtless  be  discovered 
when  needed.  There  seems  to  be  no  reason  why  agriculturalists  should  feel  the  need 
of  the  nitrogen  of  sewage  since  every  farmer  who  lives  within  reach  of  railroads  or 
steamboats  has  the  whole  world  from  which  to  draw  his  supplies  of  manure. 

In  Professor  Storer's  words: 

"No  matter  how  freely  it  may  be  admitted  that  immense  quantities  of  plant  food 
are  carried  out  from  the  city  every  year  through  the  sewers,  it  remains  none  the  less 
true  that  these  fertilizing  matters  are  carried  out  in  a  state  of  such  extreme  dilution 
that  it  is  idle  to  talk  of  recovering  any  of  them  economically  in  the  present  condition 
of  labor  and  commerce  or  of  utilizing  the  sewage  in  any  way  excepting  in  arid  regions 
and  in  some  rare  localities." 

Lawes  has  stated  the  views  of  English  experts  in  a  paper  on  "The  Disposal  of 
Sewage  by  Some  Towns  and  Villages"  in  the  Journal  of  the  Royal  Agricultural  So- 
ciety of  England,  Series  3,  Vol.  I,  1890,  page  86,  as  follows: 

"Now  that  the  sewage  question  has  been  through  the  wild  extravagance  of  its 
early  days  and  sewage  has  come  to  be  regarded  by  all  sensible  people  as  a  nuisance 


384         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

to  be  gotten  rid  of  rather  than  being  in  itself  a  mine  of  wealth,  the  solution  of  the 
problem  has  become  an  easier  matter.  The  primary  question  is  no  longer  how  to  ex- 
tract the  small  amount  of  fertilizing  matter  it  contains,  with  the  idea  of  making  a 
fortune  by  sewage  farming  or  a  valuable  artificial  manure,  but  how  to  rid  ourselves 
of  the  sewage  that  it  may  do  the  smallest  amount  of  harm  at  the  least  possible  cost." 

In  Dr.  Tidy's  opinion,  "The  story  of  one  and  all  sewage  farms  is  a  history  of  com- 
mercial failure." 

Considerations  Affecting  New  York 

As  mentioned  in  Preliminary  Report  I  of  the  Metropolitan  Sewerage  Commission, 
September,  1911,  page  5,  the  sandy  soil  of  Long  Island  lying  east  of  Greater  New 
York  between  Amityville  and  Quogue  is  the  only  region  where  it  would  be  at  all  prac- 
ticable to  treat  the  great  volume  of  the  city's  sewage,  or  any  large  part  of  it,  by  irri- 
gation. This  volume,  which  will  reach  1,330  million  gallons  by  1940,  would  require 
about  175  square  miles  for  treatment,  allowing  12,000  gallons  per  acre. 

Leaving  out  of  account  the  cost  of  the  land  the  project  is  estimated  to  cost 
$152,780.00. 

It  would  be  more  reasonable  for  the  sewage  of  parts  of  Brooklyn  and  Queens  to 
be  applied  to  farm  lands.  Aside  from  the  financial  argument  which  would  probably 
be  conclusive,  there  are  the  other  considerations  that  have  already  been  referred  to 
as  drawbacks  to  irrigation  in  the  United  States,  viz. :  possible  nuisance,  possible  con- 
tamination of  the  sources  of  well  supplies,  value  of  the  land  for  building  purposes 
and  the  uncertain  effect  of  taking  over  a  great  agricultural  enterprise  by  the  munici- 
pality with  all  its  possibilities  of  inefficiency  due  to  the  short  terms  of  office  of  those 
in  control. 

Recent  Official  Opinions  on  Utilization 

Two  reports  on  the  utilization  of  sewage  appeared  in  December,  1913,  one  in 
England  and  one  in  the  United  States.  Each  was  brief  but  well  calculated  to  show 
the  opinion  of  its  author.  The  author  was  in  each  case  qualified  in  every  way  to  form 
an  authoritative  opinion  with  respect  to  the  subject  dealt  with. 

Dr.  MacLean  Wilson  is  Chief  Inspector  of  the  West  Riding  of  Yorkshire  Rivers 
Board  and  in  this  capacity  directs  the  efforts  which  are  being  made  by  a  rural  and 
urban  population  of  over  3,000,000  persons  located  in  the  center  of  England  to  dis- 
pose of  this  sewage  in  a  sanitary  manner  and  at  the  least  practicable  cost. 

Mr.  H.  W.  Clark  is  Chemist  of  the  Massachusetts  State  Board  of  Health  and  in 
charge  of  the  Lawrence  Experiment  Station  where  a  larger  and  longer  experience 
has  been  had  in  the  disposal  of  sewage  on  an  experimental  scale  than  has  been  en- 


UTILIZATION  OF  SEWAGE  385 

joyed  elsewhere.  All  efforts  made  in  the  State  to  dispose  of  sewage  come  under  his 
critical  examination. 

Dr.  Wilson's  opinion  is  set  forth  in  an  official  report  of  the  West  Eiding  of  York- 
shire Rivers  Board;  Mr.  Clark's  in  a  monthly  bulletin  of  his  Board. 

Opinion  of  Dr.  H.  MacLean  Wilson.  In  Dr.  MacLean  Wilson's  opinion,  the  use 
of  water  carriage  for  the  removal  of  the  sewage  has  greatly  added  to  the  difficulty 
of  making  use  of  the  fertilizing  materials.  The  wastes  from  each  adult  inhabitant, 
estimated  at  about  $2.62  per  annum,  are  diluted  by  7,000  imperial  gallons  of  water 
and  to  extract  the  material  which  theoretically  is  worth  $7,500,000  would  necessitate 
dealing  with  22,000  million  gallons. 

In  practice,  Dr.  Wilson  shows  that,  owing  to  the  difficulty  of  obtaining  suitable 
land  within  reasonable  distance  of  towns  and  owing  to  the  necessity  for  dealing  con- 
tinuously with  huge  volumes  of  water  of  which  the  sewage  is  composed,  it  is  impos- 
sible to  utilize  the  sewage  profitably  in  farming  except  under  rare  circumstances,  and 
nearly  all  the  large  towns  in  England  have  found  it  necessary,  because  of  the  cost, 
to  abandon  the  use  of  their  sewage  farms  and  adopt  more  modern  methods  of  sewage 
purification. 

Dr.  Wilson  states  that  inasmuch  as  more  than  half  the  valuable  constituents  of 
sewage  are  in  solution,  unless  purification  is  accomplished  by  means  of  land  treat- 
ment, this  portion  escapes  into  the  streams  and  is  lost,  so  far  as  utilization  is  con- 
cerned. The  idea  of  discharging  sewage  effluents  into  fish  ponds  to  encourage  aquatic 
vegetation  and  so  favor  the  growth  of  insects,  crustaceans  and  other  forms  of  life 
upon  which  fish  thrive  does  not  seem  practicable  to  Dr.  Wilson  as  a  general  proce- 
dure. To  him  it  appears  necessary  to  face  the  probability  that  about  one-half  of  the 
intrinsic  value  of  the  sewage,  the  whole  of  which  is  estimated  in  his  district  to  be 
worth  about  $7,500,000  yearly,  must  be  allowed  to  escape  to  the  streams  without 
utilization. 

That  part  of  the  sewage  which  can  be  utilized  consists  in  the  sludge  which  is 
recoverable  by  screening  and  especially  by  sedimentation.  Before  it  can  be  used  Dr. 
Wilson  states  that  the  sludge  must  be  dried  either  by  filters,  so  as  to  contain  about  70 
per  cent,  of  water,  or  by  means  of  sludge  presses  to  the  form  of  a  thick  solid  cake,  in  bulk 
one-quarter  of  the  original  volume  and  in  water  about  60  per  cent.  In  either  case  it 
is  in  condition  to  be  removed  in  carts  and  spread  over  land  by  spade.  In  a  few 
towns  the  sludge  is  dried  still  further  so  that  it  can  be  ground  up  and  sold  in  the  form 
of  a  powder. 

Dr.  Wilson  describes  the  "Globe"  fertilizer  produced  at  Glasgow,  the  product  at 
Kingston-on-Thames  or  native  guano,  the  Bradford  process,  the  Oldham  method  of  dry- 


386         DATA  KELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

ing  by  means  of  heat  and  removal  of  grease  by  distillation,  all  of  which  are  described 
elsewhere  in  the  present  report  of  the  Metropolitan  Commission.  Reference  is  also 
made  of  Hebden  Bridge,  where  the  sludge  is  sold  in  a  granular  form  obtained  by  dry- 
ing the  pressed  cake  and  passing  it  through  a  disintegrator  and  Huddersfield  where  a 
new  apparatus  has  been  installed  for  wet-carbonizing  and  pressing  the  sludge,  extract- 
ing the  grease  by  means  of  a  solvent  and  reducing  the  sludge  finally  to  an  impalpable 
powder. 

In  the  West  Riding  of  Yorkshire  over  500,000  tons  of  pressed  or  filter-dried  sludge, 
containing  60  to  70  per  cent,  of  water,  are  produced  annually.  Dr.  Wilson's  report 
states  that  if  the  sludge  is  used  as  a  top  dressing  for  grass  land,  it  is  found  that  the 
grease  does  not  permit  the  sludge  to  weather  and  break  down  sufficiently  rapidly  and 
that  even  after  many  months  it  lies  in  lumps  apparently  unaltered.  If  ploughed  or 
dug  into  the  soil,  a  still  longer  time  is  required  for  it  to  become  assimilated  with  the 
humus  around  it  and,  if  used  in  large  quantities,  it  clogs  the  pores  of  the  soil  or  pre- 
vents the  percolation  of  air  and  moisture  which  are  so  important  to  plant  life.  More- 
over, the  sludge  is  likely  to  contain  seeds  of  nettles,  docks  and  other  troublesome 
weeds,  not  to  speak  of  tomatoes,  raspberries,  strawberries  and  other  fruits,  whose 
plants  spring  up  in  thousands  around  the  sludge  beds. 

Notwithstanding  its  drawbacks,  the  sludge  forms  a  valuable  manure  for  certain 
soils  and  purposes  and,  considering  its  low  cost  and  plentiful  supply,  should  be  more 
frequently  used.  Dr.  Wilson  suggests  that  a  good  way  to  use  sludge  is  to  make  it  into 
the  form  of  a  pie  with  alternate  layers  of  farmyard  manure  and  to  let  it  ripen  for 
months,  after  which  it  can  be  used  for  top  dressing  or  ploughed  into  the  soil.  This 
is  after  the  plan  of  composting,  elsewhere  referred  to  in  the  present  report  of  the  Met- 
ropolitan Sewerage  Commission. 

According  to  Dr.  Wilson,  the  manurial  value  of  sludge  does  not  vary  greatly 
whether  it  comes  from  a  town  where  the  houses  are  nearly  all  provided  with  water- 
closets  and  the  sewage  therefore  contains  all  the  excreta  of  the  inhabitants,  or  from  a 
town  where  all  the  houses  have  dry  closets  and  the  excreta  are  not  discharged  into  the 
sewers.  This  fact  is  shown  by  a  table  supplied  by  Dr.  Wilson,  containing  the  results 
of  analyses  of  the  sewage  of  about  twenty  towns.  From  the  figures  given,  it  appears 
that  sludge  containing  70  per  cent,  of  moisture  is  worth  about  $1.75  per  long  ton,  cal- 
culated on  the  basis  of  nitrogen,  phosphoric  acid  and  potash  present,  assuming  that  the 
whole  of  these  ingredients  are  present  in  available  form  and  estimating  their  prices 
from  those  of  sulphate  of  ammonia  at  about  $60;  superphosphate  at  about  $13,  and 
sulphate  of  potash  at  about  $48  per  ton. 

In  Dr.  Wilson's  opinion  the  most  substantial  reasons  for  the  unpopularity  of 


UTILIZATION  OF  SEWAGE  387 

sewage  sludge  as  a  manure  rest  upon  the  unmanageable  form  in  which  the  sludge  is 
usually  offered  for  sale  and  the  presence  of  the  relatively  large  amount  of  grease  which 
it  contains.  It  has  repeatedly  been  found  in  England  that  when  sludge  is  dried  and 
broken  up  into  a  coarse  powder,  it  commands  a  ready  sale,  either  by  direct  use  by 
agriculturists  or  to  be  strengthened  by  the  addition  of  fertilizing  compounds.  When 
the  moisture  is  reduced  from  75  per  cent,  to  25  per  cent.,  as  it  must  be  in  order  to  pro- 
duce the  powder  from  pressed  or  filtered  sludge,  the  bulk  is  greatly  diminished  and  the 
material  has  a  correspondingly  increased  commercial  value. 

The  economical  removal  of  the  grease  from  the  sludge  is  a  problem  which  Dr. 
Wilson  finds  has  not  been  solved,  although  its  solution  has  been  attempted  on  differ- 
ent lines  at  various  places. 

In  general,  the  removal  of  the  grease  necessitates,  first,  the  removal  of  the  water 
and  then  the  application  of  heat  which  has  the  agricultural  advantages  of  sterilizing 
the  disease  germs  and  destroying  the  seeds  of  hurtful  weeds,  besides  making  it  a  com- 
paratively easy  matter  to  reduce  the  sludge  to  the  form  of  a  powder.  The  removal  of 
the  grease  facilitates  the  use  of  the  sludge  in  agriculture,  for  the  material  can  then 
be  applied  to  the  land,  either  as  a  top  dressing  or  ploughed  in,  in  either  event  the 
material  breaking  down  readily  and  becoming  assimilated  with  the  soil.  Dr.  Wilson 
reports  an  increased  demand  for  this  manure. 

Taken  as  a  whole,  Dr.  Wilson's  report  takes  a  hopeful  view  of  the  possibilities  of 
utilizing  that  part  of  the  valuable  ingredients  of  sewage  which  can  be  extracted  in 
the  form  of  sludge.  An  early  solution  of  the  problem  lies,  in  his  opinion,  in  the  fact 
that  there  are  many  capable  experimenters  at  present  at  work  in  the  effort  to  prevent 
the  waste  at  a  cost  which  will  permit  the  sludge  to  be  prepared  and  transported  in  a 
condition  profitable  for  the  agriculturist. 

Opinion  of  Mr.  H.  W.  Clark.  After  reviewing  the  efforts  made  by  different  cities 
in  Germany,  England  and  America  to  make  use  of  their  sewage  since  the  middle  of  the 
last  century  and  making  some  estimates  of  the  manurial  value  of  sewage  based  on  the 
composition  of  the  fairly  strong  domestic  sewage  of  the  City  of  Lawrence  in  1912,  Mr. 
Clark  concludes  that  the  total  amount  of  fertilizing  and  fatty  matters  in  each  1,000 
gallons  of  representative  American  sewage  is  not  worth  over  6  or  8  cents.  Of  this, 
about  half  is  represented  by  the  ammonia  in  solution  and  there  is  no  method  by  which 
it  can  be  utilized  except  by  application  to  land. 

Experience  covering  many  years,  with  hundreds  of  well-operated  sewage  farms, 
has  convinced  Mr.  Clark  that  only  under  the  most  favorable  conditions  can  a  return 
from  farming  be  made  to  pay  the  operating  expenses  and  there  is  no  instance  wherein 


388         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


the  returns  both  pay  the  cost  of  operation  and  interest  on  the  capital  invested,  except 
in  regions  of  low  rainfall,  where  the  liquid  is  useful  for  irrigating  purposes. 

Mr.  Clark  estimates  that  average  American  sewage  contains  about  2,400  pounds 
of  sedimentable  matter  in  a  million  gallons  and  that  the  nitrogen,  fats,  etc.,  in  this 
material  are  worth  about  $15  to  $18.  In  order  to  reclaim  the  useful  material,  he  points 
out  that  the  solids  must  be  removed,  dried,  pressed  and  subjected  to  a  process  for  the 
separation  of  grease  from  the  fertilizing  constituents,  for  only  by  this  separation  can 
the  grease  become  an  article  of  commerce  and  the  fertilizing  constituents  be  of  real 
agricultural  value.  Only  in  a  few  places  is  the  separation  of  the  grease  attempted  as  a 
commercial  enterprise  and  the  profitableness  of  these  works  is  doubtful. 

After  the  sludge  is  practically  freed  from  its  fats,  it  consists,  in  a  large  part,  Mr. 
Clark  says,  of  inert  mineral  and  organic  matter  mixed  with  a  comparatively  small 
weight  of  fertilizing  materials  and  consequently  the  cost  of  carriage  is  great  even 
when  the  sludge  is  well  dried. 

Mr.  Clark  considers  that  it  is  well  proved  that  the  nitrogen,  phosphatic  acid,  etc., 
are  generally  in  less  assimilable  form  than  are  the  same  bodies  in  ordinary  commer- 
cial fertilizers.  The  opinion,  expressed  by  Mr.  Clark  as  the  result  of  his  study,  is  that 
the  sludge  has  some  value  and  as  the  processes  of  drying,  pressing  and  fat  separa- 
tion are  improved  and  as  nitrogen  advances  in  price,  it  seems  to  him  inevitable  that 
sewage  sludge  will  become  of  greater  agricultural  value  than  it  is  at  present,  espe- 
cially as  the  basis  of  fertilizers  enriched  by  the  addition  of  potash,  phosphates,  etc. 

SLUDGE 

When  the  normal  flow  which  is  customarily  maintained  in  sewers  in  order  that 
they  shall  be  self-cleansing  is  checked  and  the  sewage  comes  to  a  state  of  more  or  less 
complete  rest,  a  deposit  forms  which  is  termed  sludge.  This  deposit  is  so  easily  obtained 
and  the  removal  of  the  sludge  is  such  a  useful  step  toward  the  purification  of  sewage 
that  sedimentation  has  become  an  almost  invariable  part  of  disposal  works. 

Sludge  is  a  mixture  of  particles  of  various  degrees  of  density  ranging  from  fine 
sand  and  fleshy  substances  of  animal  and  vegetable  origin  to  particles  in  a  semi- 
liquid  condition.  Semi-solid  matters  called  colloids  are  characteristic  of  sludge.  They 
contain  a  large  proportion  of  water  which  they  part  with  only  with  much  difficulty. 
In  order  that  the  water  may  be  removed,  it  is  necessary  to  change  the  physical  condi- 
tion of  the  colloid  particles.  This  can  be  done  by  heat  and  by  fermentation.  On  ex- 
posure to  the  atmosphere  and  by  providing  free  drainage,  the  water  is  removed  with 
great  difficulty. 

The  density  of  sludge  depends  upon  many  factors,  including  the  composition  of 


UTILIZATION  OF  SEWAGE 


389 


the  sewage  from  which  the  sludge  was  derived,  the  length  of  the  period  afforded  for 
settlement,  the  length  of  time  during  which  the  sludge  was  stored  and  its  accessibility 
to  air  or  oxygen  in  the  water  or  sewage  which  happens  to  be  overlying  the  sludge. 

Sludge,  when  fresh,  is  usually  dark  in  color,  of  unpleasant  odor  and  of  a  con- 
sistency resembling  thin  mud.  It  becomes  more  dense  and  pasty  with  drying.  It  can 
be  pumped,  but  it  cannot  well  be  shoveled  until  it  has  parted  with  about  one-third  of 
its  moisture. 

Oxygen  generally  does  not  have  access  to  the  interior  of  sludge  masses  for  the 
reason  that  free  circulation  does  not  occur  and  active  anaerobic  decomposition  soon 
begins  under  ordinary  conditions  of  temperature.  If  the  sludge  is  overlaid  with  sew- 
age, ill-smelling  gases  may  be  produced  in  large  quantity  and  these  escape  at  the  sur- 
face in  the  form  of  bubbles.  The  odors  are  largely  due  to  the  formation  of  sulphur- 
etted hydrogen  and  to  organic  gaseous  compounds  of  complex  nature. 

If  the  sludge  is  permitted  to  ferment  with  little  or  no  sewage  over  it,  odors  are  to 
a  great  extent  prevented.  Anaerobic  decomposition  will  not  long  proceed  in  a  mass  of 
sludge  unless  provision  is  made  for  stirring  it  or  otherwise  causing  a  circulation.  A 
barrelful  of  sludge  may  remain  with  little  apparent  change  in  its  physical  condition 
for  many  months.  If,  however,  small  amounts  of  sludge  are  added  at  frequent  in- 
tervals and  the  fermented  product  removed  from  time  to  time,  vigorous  fermentation 
may  occur  and  the  entire  mass  markedly  change  in  physical  composition. 

In  the  fermented  state  the  sludge  is  charged  with  gas  bubbles,  the  peculiarly 
gelatinous  state  of  the  colloid  particles  disappears  and  a  large  amount  of  the  con- 
tained liquid  can  be  freely  drained  away.  Well  fermented  sludge  is  inoffensive  and 
incapable  of  producing  objectionable  odors;  it  resembles  humus  or  garden  mould  in 
many  respects. 

The  objectionable  gases  which  arise  from  unfermented  sludge  may  be  diminished 
in  volume  by  the  addition  of  iron  and  various  other  chemical  compounds  to  the  sew- 
age. A  small  amount  of  iron  is  always  present,  this  element  being  well-nigh  universal 
in  nature.  When  sewage  or  sludge  decomposes  in  the  absence  of  oxygen,  it  is  chiefly 
a  combination  of  the  iron  and  the  sulphur  which  causes  the  mass  to  become  black. 

Chemically  precipitated  sludge  contains  not  only  all  the  solid  and  semi-solid  in- 
gredients commonly  found  in  ordinary  sludge,  but  considerable  quantities  of  the  pre- 
cipitating agents  and  much  colloid  matter  as  well.  The  chemicals  may  or  may  not 
produce  a  restraining  effect  upon  the  behavior  of  the  sludge  in  respect  to  fermenta- 
tion, depending  upon  their  character  and  amount.  They  may  facilitate  filter  pressing, 
but  they  have  the  disadvantage  of  greatly  increasing  the  bulk  of  the  sludge  produced. 


390 


DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


Chemical  Composition 

The  analyses  shown  in  Tables  Nos.  LXVIII  to  LXX  give  the  chemical  composition 
of  some  sludges  obtained  in  various  places  in  the  United  States  and  Europe  by  plain 
sedimentation  and  chemical  precipitation.  They  also  give  the  composition  of  fresh  and 
septic  sludge  and  the  product  of  septic  tanks  and  Emscher  tanks. 


TABLE  LXVIII 
Percentage  Composition  op  Fresh  and  Septic  Sludge* 


Fresh 

Volatile  solids   45.8 

Fixed  solids   54.2 

Nitrogen   2.0 

Carbon   27.9 

Fats   15.8 


Septic 

32.6 

67.4 

1.3 
19.5 

8.0 


TABLE  LXIX 
Sludge  from  Emscher  Tanks 


City 


Philadelphia1 

Chicago3  

Recklinghausen4 

Essen*  

Bochum4  


Of  Dry  Residue 

Moisture 

Mineral 

Organic 

Nitrogen 

Fats 

82.5 

62 

38 

1.2 

6.5 

288 

61 

39 

82.9 

54.7 

45.3 

1.74 

6.87 

75.6 

45.1 

54.9 

1.22 

4.95 

78.1 

61 

38.1 

1.18 

6.12 

TABLE  LXX 
Sludge  from  Chemical  Precipitation 


Dried  at  About  110°  C. 


Moisture 

Mineral 

Volatile 

Nitrogen 

PtO, 

Kingston — Native  Guano6  

25.67 

36.14 

37.99 

1.93 

1.74 

37.67 

37.52 

24.81 

.89 

0.66 

Chorley — Alumino-ferrio6  

12.50 

50.74 

36.76 

1.28 

0.98 

Leeds — Alton's  Process5  

22.06 

30.67 

47.27 

1.04 

2.12 

Glasgow — Globe  Fertilizer5  

22.51 

43.51 

33.98 

1.30 

1.11 

*Sewage  Disposal,  p.  142,  Kinnicutt,  Winslow  &  Pratt. 

'Report  on  Sewage  Test.  Sta.  1911;     286  to  90;     'Report  Geo.  M.  Wisner,  Sanit.  Dist.  Chicago. 
4Sewage  Sludge,  p.  180. 
'Report  Royal  Com.  Sew.  Disp. 
V.  App.  VIII,  p.  9. 


Volume  and  Weight 

In  general  it  may  be  said  that  plain  sedimentation  will  produce  from  4  to  7  cubic 
yards  of  sludge  of  from  87  to  93  per  cent,  moisture;  septic  tanks  1.5  to  3  cubic  yards 
of  from  80  to  90  per  cent,  moisture ;  Emscher  tanks  1  to  2.5  cubic  yards  of  from  75  to 


UTILIZATION  OF  SEWAGE 


391 


85  per  cent,  moisture,  and  chemical  precipitation  tanks  20  to  25  cu.  yds.  of  from  86  to 
92  per  cent,  moisture  per  million  gallons  of  sewage.  Some  examples  are  given  in 
Table  LXXI. 

TABLE  LXXI 

Peb  Cent.  Moistube  Pboduced  by  Plain  Sedimentation,  Scientific  Tbeatment  and 

Chemical  Pbecipitation 


Frankfurt  

Bremen  

Hanover  

Mannheim. . . . 

Cassel  

Readingf  

Philadelphia^ . 


Manchester. . 
Accrington. . , 

Hampton  

Birmingham. 

Stuttgart  

Merseberg. . . 


London  

Salford. . . . 

Leeds  

Sheffield. . . 
Providence. 
Worcester. . 


For  Plain  Sedimentation' 


Cubic  Yards  per 
Million  Gallons 


16.3 
10.9 

9.9 
10.9 
23.8 

3  3 
4.7  to  6.31 


Cubic  Yards  per  1,000 
Population  Daily 


.930 
.655 
.301 
.877 
.628 


For  Septic  Treatment* 


12.0 
7.9 
4.36 
16.85 
18.6 
8.2 


0.62 


0.50 
0.10 


For  Chemically  Precipitated  Sludge§ 


25.2 
45.6 
19.4 
14.2 
19.4 
24.3 


•Sewage  Sludge,  Eisner,  Spiller,  Allen,  pages  18-19. 
tSewage  Sludge,  Eisner,  Spiller,  Allen,  page  217. 

JReport  on  Sewage  Testing  Station,  Bureau  of  Surveys,  Phila.,  1911,  page  161. 
§Sewage  Disposal,  Fuller,  page  93. 

Koelle**  gives  for  Frankfort,  with  92,000  inhabitants,  335,000  cu.  m.  of  sludge  or 
274  cu.  yds.  per  1,000  persons.  Dunbar  estimates  that  the  weight  of  sludge  produced 
per  year  from  the  sewage  of  1,000  persons  will  be  110  tons  by  plain  sedimentation  and 
three  times  this  amount  by  chemical  precipitation.ff 

As  to  weight,  undecomposed  sludge  and  chemically  precipitated  sludge  are  taken 
to  have  the  weights  given  in  Tables  Nos.  LXXII  and  LXXIII. 

**Guide  to  some  of  the  public  works  to  Frankfort-on-the-Main — Koelle. 
ffPrinciples  of  sewage  treatment,  Dr.  Dunbar  and  H.  T.  Calvert,  1908,  page  262. 


392         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

TABLE  LXXII 
Weight  of  Chemically  Precipitated  Sludge* 

Tons  per  Moisture,  per 

Million  Gallons  cent 

Strong  European  sewages                                                       25-35  90 

American                                                                            15-20  90 

London  sewage                                                                 30  91 

Worcester  sewage                                                                 20.6  93 

Providence  sewage                                                                16.5  91.6 


TABLE  LXXIII 

Approximate  Weight  and  Volume  of  One  Cubic  Yard  of  Wet  Undecomposed 

SLUDGEf 


Specific 

Gravity 

Per  Cent. 

1.02 

1. 

04 

1. 

06 

Moisture 

Pounds,  per 

Cubic  Yards 

Pounds,  per 

Cubic  Yards 

Pounds,  per 

Cubic  Yards 

Cubic  Yard 

Per  Ton 

Cubic  Yard 

per  Ton 

Cubic  Yard 

per  Ton 

100  

1685 

1.190 

1685 

1.190 

1685 

1.190 

95  

1700 

1.176 

1720 

1.163 

1735 

1.149 

90  

1720 

1.163 

1755 

1.136 

1785 

1.124 

85  

1735 

1.149 

1785 

1.124 

1835 

1.087 

80  

1755 

1.136 

1820 

1.099 

1905 

1.053 

*Sewage  Disposal — Kinnicutt,  Winslow  and  Pratt,  page  167. 
tSewage  Disposal — Fuller,  page  447. 


Disposal  of  Sludge 

The  simplest  and  most  satisfactory  methods  of  disposition  are  irrigation  and  air 
drying. 

Irrigation  toith  Wet  Sludge.  The  wet  sludge  may  be  applied  directly  to  the  land 
in  a  way  similar  to  sewage  irrigation.  It  can  be  run  into  trenches,  covered  with  2  or 
3  inches  of  soil  and  the  land  used  the  succeeding  year  or  two  for  cultivation.  The  size 
and  arrangement  of  the  trenches  depends  largely  upon  the  absorptive  properties  of 
the  soil.  Under  favorable  conditions  trenches  may  be  2  or  3  feet  wide,  12  to  20  inches 
deep  and  about  5  feet  apart. 

At  Birmingham  about  3,000  lin.  ft.  of  trench  3  ft.  wide  on  top  and  18  inches  deep 
were  required  daily  to  dispose  of  1,000  short  tons  of  sludge  (94.5%  moisture).  By  cul- 
tivation during  the  intervening  time  the  operation  could  be  repeated  in  from  18 
months  to  2  years. 

The  Royal  Commission  on  Sewage  Disposal  estimates  the  area  required  as  shown 
in  Table  No.  LXXIV. 


UTILIZATION  OF  SEWAGE 


393 


TABLE  LXXIV 


Area  Required  for  Disposing  op  Sludge  by  Irrigation 


Tons  90%  Water    Area  Required  per 
per  Million  Million  Gallons 

Gallons  Daily — Acres 


With  plain  sedimentation  (continual  flow) . . . 

With  septic  tanks  

With  chemical  precipitation  (continual  flow) 


10.1  3.68 
6.0  2.17 
14.7  5.32 


General  figures  relating  to  sludge  should  be  used  with  caution,  as  much  depends 
on  the  climate,  the  character  of  the  soil  and  its  treatment,  and  the  character  of  the 
sludge,  aside  from  its  moisture. 

The  disposal  of  sludge  by  burying  is  often  preceded  by  allowing  it  to  flow  upon 
drying  beds  and  into  lagoons  in  order  to  reduce  the  water  content;  in  this  way  some 
saving  is  effected  in  the  land  required  for  the  final  disposition.  In  many  cases 
lagoons  and  drying  beds  afford  all  the  preparation  which  the  sludge  receives  before  it 
is  disposed  of  by  dumping  upon  low-lying  land.  The  figures  shown  in  Table  LXXIV 
apply  particularly  to  treatment  on  drying  beds  and  in  lagoons  preparatory  to  removal 
for  the  final  disposition. 

The  time  of  drying  depends  on  the  composition  and  condition  of  the  sludge,  the 
amount  of  water  present,  facilities  for  drainage,  the  exposure  of  the  sludge  to  the 
weather,  humidity  and  wind. 

To  be  spadable,  sludge  must  not  contain  much  over  60  or  70  per  cent,  of  moisture. 
Plain  settled  sludge  usually  requires  6  to  8  weeks  in  summer  and  6  months  in  cold 
weather  and  septic  tank  sludge  takes  2  weeks  in  good  weather  and  Emscher  tank 
sludge  usually  about  5  days  to  dry  to  this  state  under  favorable  conditions. 

About  one  acre  per  million  gallons  of  sewage  is  a  fair  allowance  for  sludge 
drying. 

It  may  be  said,  in  general,  that  there  is  no  revenue  to  be  expected  from  any  of 
these  methods  of  air-drying.  If  plenty  of  suitable  land  is  available,  there  will  be  a 
certain  economy  in  using  the  sludge  so  dried  as  a  fertilizer,  but  no  results  compar- 
able with  those  obtained  from  artificial  fertilizers  can  be  looked  for,  and  this  method 
is  usually  only  applicable  to  small  plants.  There  are  several  reasons  for  this.  In 
order  to  be  efficiently  used  as  fertilizer,  the  sludge  should  be  furnished  only  as  re- 
quired. The  large  volume  of  moisture  which  fresh  sludge  contains  renders  initial 
drying  desirable  and  in  this  case  there  is  expense  for  handling.  The  grease  contained 
also  prevents  the  useful  ingredients  of  sludge  from  being  readily  assimilated. 

Unless  derived  from  septic  or  Emscher  tanks  or  buried  in  trenches,  there  is  almost 
certain  to  be  an  evolution  of  foul  gases  and  odors  and  the  nuisance  of  flies,  besides 
which  the  liquids  draining  off  are  so  offensive  as  to  require  treatment.    Mr.  Watson 


394         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

has  found  bleach  useful  in  preventing  the  occurrence  of  odors  and  flies  at  Birming- 
ham. He  has  applied  it  at  the  rate  of  30  lbs.  of  bleach  containing  36.35  per  cent, 
available  CI  per  100  cu.  yds.  of  sludge.  At  Biebrich,  Germany,  from  .1  to  .2  gallons 
of  "facilol,"  and  at  Frankfort  from  .1  to  .2  gallons  of  "facilol"  per  sq.  yd.  of  exposed 
surface  of  sludge  has  proved  effective.  Facilol  is  an  oil  having  a  specific  gravity 
equal  to  0.79  and  costs  there  lSy2  cents  per  gallon.  A  covering  of  peat  has  sometimes 
been  found  to  be  a  good  deodorizer  for  sludge.  At  Cassell,  7  pounds  of  lime  per  cu. 
yd.  of  sludge  was  found  a  good  preventive  for  flies  although  reducing  the  value  of 
the  sludge  as  a  fertilizer.  In  spite  of  efforts  made  to  the  contrary,  sludge  beds  almost 
always  prove  to  be  a  nuisance. 

The  cost  of  air-drying  septic  sludge  at  Birmingham  by  spreading  on  land  pre- 
viously plowed  is  stated  by  the  Royal  Commission  on  Sewage  Disposal  in  its  Fifth 
Report  to  have  been,  for  the  Saltley  Works,  2.67  cents  per  ton  and  for  the  Minworth 
Works,  2.40  cents  per  ton. 

Pressed  Sludge 

When  it  is  desired  to  remove  the  greatest  practicable  amount  of  suspended  solids 
and  colloidal  matter  from  sewage,  recourse  may  be  had  to  chemical  precipitation. 
This  process  is  particularly  applicable  to  sewage  which  contains  trade  waste  which 
makes  it  difficult  to  treat  satisfactorily  by  plain  sedimentation.  The  sludge  obtained 
from  chemical  precipitation  plants  may  be  concentrated  by  pressure  in  filter  presses 
in  the  form  of  cakes,  the  contained  moisture  being  reduced  to  about  60  per  cent. 

The  moisture  contained  in  sludge  cake  can  be  reduced  by  air-drying  and  by  heat. 
When  kept  protected  from  rain  and  sun,  sludge  cake  remains  inoffensive  and,  after 
air-drying,  may  be  used  for  filling  in  land. 

Sludge  from  plain  sedimentation  or  when  containing  much  grease  cannot  be 
readily  pressed;  in  the  former  case  passing  through  the  filter  cloths  and  in  the  latter 
clogging  them.  Even  with  sludge  produced  by  chemical  precipitation,  it  is  often  neces- 
sary to  add  8  or  10  lbs.  of  lime  per  cubic  yard  of  sludge  before  pressing.  This  adds  to 
the  cost  of  the  process  and  increases  the  bulk  to  be  disposed  of. 

It  has  been  stated  that  septic  or  digested  sludges  may  be  pressed  without  difficulty, 
but  evidence  furnished  the  Royal  Commission  on  Sewage  Disposal  and  presented  in  its 
Fifth  Report  seems  to  refute  this  claim.  Digested  sludge,  nevertheless,  drains  and 
dries  with  much  less  difficulty  than  does  fresh  sludge  and  less  nuisance  is  caused  by  it. 

The  following  are  a  few  examples  of  works  in  which  sewage  sludge  is  pressed. 

Worcester,  Mass.  Here  the  sewage  contains  much  trade  waste  from  wire  mills, 
foundries  and  tanneries  and  is  normally  acid.    The  sludge,  containing  92.4  per  cent. 


UTILIZATION  OF  SEWAGE 


395 


moisture,  is  first  dosed  with  from  6  to  10  lbs.  of  lime  per  cubic  yard  and  then  sub- 
jected to  a  pressure  of  80  lbs.  per  square  inch.  The  cake  produced  in  1910,  of  69.4 
per  cent,  moisture,  amounted  to  3.7  tons  per  million  gallons  of  sewage  or  0.167  ton  per 
cubic  yard  wet  sludge. 

Providence,  R.  I.  The  sewage  contains  wastes  from  wool  washing,  dyeing  and 
bleaching  establishments.  In  the  year  1911,  4,657  million  gallons  were  treated  chem- 
ically, producing  about  124,000  cu.  yds.  of  sludge,  or  26.6  cu.  yds.  containing  92.57 
per  cent,  water  per  million  gallons  of  sewage.  Of  this,  101,500  cu.  yds.  were  pressed 
after  the  addition  of  10.9  lbs.  of  lime  per  cubic  yard  of  sludge.  There  are  18  presses ; 
the  pressure  used  varies  from  60  to  80  lbs.  per  square  inch.  There  were  28,819  tons  of 
cake  produced  in  1911,  which  is  equivalent  to  .284  ton  per  cubic  yard  of  wet  sludge. 

Glasgow,  Scotland  (Dalmarnock  Works).  The  sewage  contains  much  trade  waste 
from  chemical,  textile,  iron,  paper  and  cotton  works,  is  variable  in  character  and  diffi- 
cult to  treat.  The  chemicals  used  for  precipitation  are  lime,  sulphate  of  iron,  nitrate 
of  soda  and  sulphuric  acid.  Two  and  three-quarter  tons  or  3^  cu.  yds.  of  sludge  con- 
taining 90  per  cent,  moisture  are  produced  per  million  gallons  of  sewage.*  This  is 
pressed  to  a  state  in  which  it  contains  66  per  cent,  moisture. 

Bradford,  England  (Esholt  Works).  Bradford  is  at  the  center  of  the  English 
woolen  industry  and  the  sewage  is  very  foul,  containing  large  quantities  of  grease, 
soap  and  suspended  solids.  The  following  analysis  of  the  sewage  gives  some  of  the 
principal  ingredients  in  parts  per  million : 


The  sludge  is  produced  by  treating  the  sewage  with  sulphuric  acid,  3  long  tons  per 
million  imperial  gallons  of  sewage  being  the  proportion  of  chemical  used.  When 
drawn  from  the  tanks,  the  sludge  contains  80  per  cent,  moisture.  It  is  then  passed 
through  a  i/i-inch  bar  screen,  heated  by  steam  and  pressed  at  60  lbs.  per  square  inch. 
One  hundred  and  thirty-two  presses  are  required  to  handle  the  670  tons  of  wet  sludge 
produced  daily.  The  pressed  cake  has  about  28  per  cent,  moisture  and  contains  com- 
paratively little  grease,  which  passes  off  while  warm  with  the  drainage  water. 

Spandau,  Germany.  The  daily  flow  of  sewage  to  the  Spandau  plant  is  2,400,000 
gallons  per  day  from  80,000  inhabitants ;  it  includes  some  trade  wastes.  It  is,  accord- 
ing to  American  standards,  a  very  strong  sewage,  containing  over  1,000  parts  per 
million  of  solids  in  suspension.  It  is  treated  as  follows  by  what  is  known  as  the 
Degener  process. 

In  the  Degener  process  brown  coal  or  lignite  is  first  rough-ground,  put  through 

*Sewage  Disposal,  Kinnicutt,  Winslow  &  Pratt,  p.  99. 


Suspended  matter  

Total  organic  matter  

Organic  matter  in  solution 
Grease  


800 
1,300 
670 
440 


396         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

a  fine  grinding  mill  and  then  mixed  with  water.  It  passes  to  a  tank  where  more  water 
and  sulphate  of  alumina  are  added  and  then  by  a  trough  with  baffles  to  one  of  five 
vertical  sewage  settling  tanks  or  towers  of  steel,  each  containing  a  conical  baffle 
and  a  mechanically-operated  stirrer.  Sedimentation  takes  place  in  the  steel  towers, 
removing  90  per  cent,  of  the  suspended  solids  and  producing  10.4  tons  of  sludge  per 
million  gallons  of  the  original  sewage.  This  reduces  its  moisture  to  60  per  cent.  The 
sludge  is  then  filter-pressed  under  a  pressure  of  from  60  to  80  lbs.  per  square  inch  for 
20  hours,  after  which  it  is  removed  to  tip  cars  which  are  waiting.  The  sludge  cake 
is  practically  odorless  and  from  1*4  to  2^  inches  thick.  There  is  a  noticeable  ab- 
sence of  odor  about  the  plant  and  the  effluent  which  passes  to  the  river  Havel  is  clear. 

Cost  of  Pressing.  The  cost  of  pressing  sludge  is  usually  combined  with  the  cost 
of  precipitation  in  consequence  of  which  it  is  difficult  to  ascertain  its  cost  separately. 

At  Providence,  in  1910,  the  cost  of  precipitation  was  |3.11  and  the  cost  of  sludge 
disposal  was  $4.06  per  million  gallons  sewage.  The  cost  of  pressing  the  sludge  was 
$2.62  per  ton  of  solids. 

At  Worcester,  in  1910,  the  total  cost  of  precipitation  and  disposal  was  $4.53  per 
million  gallons  of  sewage  or  $3.88  per  ton  of  solids. 

At  Glasgow,  in  the  year  1911-1912,  there  were  produced  per  million  gallons  of 
sewage  36.7  tons  of  wet  sludge  and  6.88  tons  of  pressed  cake  at  a  cost  of  $2.22  per 
million  gallons  of  sewage  or  39  cents  per  ton  of  cake. 

At  Spandau,  the  lignite  (at  $1.10  per  ton)  and  the  sulphate  of  alumina  cost 
$8,400  per  annum,  $9.60  per  million  gallons  of  sewage  and  $0.94  per  ton  of  wet  sludge. 
The  costs  of  operation  are  $21,500  per  annum,  $24.50  per  million  gallons  of  sewage 
and  $2.35  per  ton  of  wet  sludge.  About  6%  tons  of  lignite  and  1,600  lbs.  of  sulphate 
of  alumina  are  required  per  million  gallons.  The  cost  per  inhabitant  per  year  is  33.1 
cents. 

The  cost  of  pressing  varies  greatly,  depending  largely  on  the  cost  of  the  lime  or 
other  chemicals  and  the  nature  of  the  sludge.  It  also  depends  on  the  size  of  the  plant. 
Experience  in  pressing  has  been  more  extensive  in  England  than  elsewhere,  in  conse- 
quence of  which  peculiar  value  attaches  to  the  opinions  reached  by  the  Royal  Com- 
mission on  Sewage  Disposal  in  regard  to  this  subject. 

Eisner  gives  the  cost  of  pressing  sludge  in  Germany  as  from  6Sy2  to  85  cents 
per  ton  of  cake;  Reichle  and  Thiesing  (without  the  addition  of  lime,  but  including 
fixed  charges)  49  cents  under  favorable  conditions,  while  Schiele  estimates  the  cost 
under  English  conditions  at  from  42  cents  to  $1.28  per  ton.  According  to  Moore  and 
Silcock,  in  their  "Sanitary  Engineering,"  the  cost  of  pressing,  per  ton  of  wet  sludge, 
is,  exclusive  of  fixed  charges,  24.2  cents  at  Manchester.    According  to  Raikes,  in  his 


UTILIZATION  OF  SEWAGE 


397 


"Sewage  Disposal  Works,"  a  complete  plant  sufficient  to  press  33  tons  per  day  costs 
in  England  about  $3,900  and  the  cost  of  pressing  varies  from  iy2  to  11  cents  per  ton 
of  wet  sludge  or  from  43^2  to  54  V£  cents  per  ton  of  cake. 

According  to  George  C.  Whipple,  the  value  of  pressed  sludge  is  seldom  equal 
to  the  cost  of  the  lime  and  pressing.  When  taken  by  farmers  it  sometimes  about 
pays  for  these  charges,  but  otherwise  there  is  a  loss. 


Centrifugal  machines  for  drying  sludge  require  less  space  and  auxiliary  machin- 
ery than  presses  and  have  the  further  advantage  of  not  requiring  the  addition  of  lime 
or  heat  for  their  proper  operation. 

A  centrifugal  sludge  machine  has  been  designed  after  much  experimentation  in 
Germany  by  Stadtbaumeister  Schaefer  of  Frankfort.  It  is  now  in  operation  at 
Frankfort,  Hanover  and  Harburg.  In  operation,  the  sludge  passes  through  a  0.4- 
inch  screen  to  an  elevated  storage  tank,  from  which  it  is  admitted  to  the  rotating 
chambers  of  the  machine.  A  period  of  2V2  to  3  minutes  is  required  to  complete  the 
cycle  of  filling,  dewatering  and  emptying  the  sludge.  The  product  contains  from  60 
to  70  per  cent,  moisture.  Once  in  about  10  minutes  the  interior  of  the  machine  is 
cleaned  by  flushing  with  water. 

Hanover.  The  data  contained  in  Table  LXXV  have  been  furnished  by  the  manu- 
facturers of  the  centrifugal  machines  used  at  Hanover. 


Centbifugalized  Sludge 


TABLE  LXXV 


Cost  of  Centrifugalizing  Sludge  at  Hanovee 


Population  

Sewage  per  day  

Wet  sludge  per  day  

Resulting  dried  sludge  

Number  of  centrifugal  machines 


280,000 
7,920,000  gallons 
130  to  195  cubic  yards 
2.62  to  3.92  cubic  yards 


4 


Cost,  per  Month 


Machinists  (day  and  night  shift)  , 

Laborers  (for  drying  machines)  

Coal  (for  gas  generators)  

Electric  current  (for  lighting  and  for  circulating  pump) 
Oil  and  waste-cleaning  tanks,  etc.  (2  men  in  day  shift) . 


$136.25 
62.50 
82.50 
40.00 
43.75 


Total,  30  days  at  $13.50 


$405.00 


From  the  above,  we  have — 


Cost  per  head  of  population  daily. 
Cost  per  million  gallons  of  sewage 
Cost  per  cubic  yard  of  wet  sludge. 


Cost  per  cubic  yard  of  dried  material 


$1.70 


6.88  to  10.3  cents 
33.7  to  51.6  cents 


0.005  cents 


Frankfort.  At  Frankfort  there  are  8  machines,  each  having  a  capacity  of  about 
4  cu.  yds.  of  wet  sludge  and  turning  out  from  6G0  to  1,000  lbs.  of  dried  product  per 
hour.    Six  of  these  are  usually  in  operation,  two  being  held  in  reserve.    They  deal 


398        DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

with  325  cu.  yds.  of  wet  sludge  per  day  of  10  hours.  The  moisture  is  reduced  from  90 
per  cent,  in  the  raw  sludge  to  from  50  per  cent,  to  70  per  cent,  in  the  product;  the 
volume  is  reduced  from  one-seventh  to  one-fifth  of  the  volume  of  the  raw  sludge.  The 
cost  of  operation  is  from  9  to  15  cents  per  cubic  yard  of  wet  sludge. 

These  figures  compare  favorably  with  those  for  sludge  pressing,  especially  when 
the  cost  of  land,  plant  and  chemicals  and  the  volume  of  dried  material  in  each  case 
are  taken  into  account;  but  the  effluent  is  not  so  well  clarified  as  when  precipitation 
is  resorted  to  nor  is  the  moisture  reduced  to  the  same  extent. 

Drying  Sludge  by  Heat 

Although  sludge  may  be  dried  directly  by  heat,  it  is  usually  cheaper  first  to  reduce 
the  moisture  to  50  per  cent,  or  60  per  cent,  either  by  pressing  or  centrifugalizing  it. 
The  object  of  drying  is  generally  to  reduce  the  bulk  and  weight  so  that  the  sludge  may 
be  transported  conveniently  and  to  prevent  putrefactive  changes.  Sometimes  the 
principal  aim  is  to  obtain  a  product  that  can  be  utilized  more  readily  than  crude 
sludge. 

It  is  not  common  to  dry  beyond  50  per  cent,  moisture  by  pressing.  Drying  by 
heat  is  practiced  at  the  Dalmarnock  works  at  Glasgow,  Scotland,  at  Bradford,  Old- 
ham, Norwich  and  Kingston,  England. 

At  Glasgow  the  sludge  cake  is  raised  by  an  elevator  and  delivered  through  a  chute 
to  a  dryer  consisting  of  an  inclined  plate  heated  by  a  furnace.  By  an  iron  scraper 
shaped  like  the  letter  L,  the  material  is  gradually  pushed  down  the  plate  to  the  lower 
end  and  then  carried  by  a  screw  conveyor  to  a  14-inch  mesh  screen  which  revolves  on 
a  horizonal  axis.  The  screen  is  36  inches  long,  about  18  inches  diameter  at  one  end 
and  24  inches  at  the  other.  The  coarse  material  retained  by  the  screen  is  conveyed  to 
the  hot  inclined  plate  and  passes  over  it  again.  The  dried  and  screened  material  goes 
to  a  pug  mill  where  it  is  ground  to  powder.  It  is  then  known  as  "Globe  Fertilizer." 
Two  analyses  of  this  fertilizer  given  in  the  Fifth  Report  of  the  Royal  Commission  are 
contained  in  Table  LXXVI. 

TABLE  LXXVI 
Composition  of  Globe  Fertilizer  Produced  at  Glasgow 

Per  Cent.  Per  Cent. 

Moisture  (at  about  110°  C.)   22.51  18.60 

Volatile  matter   33.98  35.20 

Non-volatile  matter   43.51  46.20 

100.00  100.00 

The  cost  of  producing  Globe  Fertilizer,  excluding  the  cost  of  pressing,  is  $1.20 
per  ton. 


UTILIZATION  OF  SEWAGE  399 

At  Bradford  about  a  quarter  of  the  sludge  cake  from  the  presses,  or  enough  to 
supply  the  demand,  is  dried  and  sold  to  a  fertilizer  company.  The  cake  is  first  broken 
up  in  a  simple  mill  and  is  then  dried  from  50  per  cent,  to  about  10  per  cent,  moisture 
in  a  rotary  dryer.  The  dryer  consists  of  two  concentric  horizontal  steel  cylinders. 
The  sludge  cake  is  fed  to  the  annular  space  between  the  cylinders  at  one  end  and  de- 
livered in  a  dried  condition  to  an  elevator  at  the  other  end.  The  hot  gases  from  a 
furnace  enter  the  central  cylinder  at  the  same  end  as  the  sludge,  are  cooled  from  per- 
haps 1400°  to  250°  in  the  passage  and  return  through  the  annular  space  containing 
the  sludge.  In  the  return  the  gases  are  cooled  to  100°  if  forced  draught  is  employed 
and  the  sludge  heated  to  about  212°.  The  loss  of  heat  in  the  exhaust  is  but  about  7 
per  cent,  and  the  efficiency  of  the  plant,  based  upon  the  calorific  value  of  the  fuel,  some 
70  or  75  per  cent.  In  a  test  lasting  96  hours  the  cost  for  fuel  and  labor  was  $12.94 
or  33.6  cents  per  ton.  If  the  first  cost  of  the  dryer  is  taken  at  $4,000,  the  fixed  charges 
at  5  per  cent,  and  the  capacity  at  40  tons  of  product  per  10  hours,  we  may  estimate  the 
total  cost'  per  ton  dried  from  50  per  cent,  to  10  per  cent,  moisture,  as  indicated  in 
Table  LXXVII. 

TABLE  LXXVII 
Cost  of  the  Fertilizer  Produced  at  Bradford 

Operating  costs: 

Coal  at  $3  per  ton   38  cents 

Stoker  at  20c.  per  hour   5  " 

Man  feeding  and  delivering  at  20c.  per  hour   5  " 

Oil,  Waste  and  Miscellaneous  expenses   5  " 

53  cents 

4000x.05  2  " 

Fixed  Charges   365x  40  55  cents 

The  material  as  delivered  is  in  the  form  of  small  pellets  the  size  of  pears  which 
are  inodorous  and  non-putrefactive. 

Kingston-on-Thames.  As  stated  in  the  Fifth  Report  of  the  Royal  Commission  on 
Sewage  Disposal  the  sewage  is  treated  with  alumino-ferric,  blood,  charcoal  and  clay. 
The  sludge  is  pressed,  dried,  passed  through  a  sieve,  dried  further  and  is  then  known 
as  "Native  Guano."  The  precipitation  and  sludge  disposal  cost  42%  cents  per  capita 
annually.    Two  samples  analyzed  are  shown  in  Table  LXXVIII. 

TABLE  LXXVIII 
Composition  of  Fertilizer  Produced  at  Kingston-on-Thames 

Per  Cent.  Per  Cent. 

Moisture                                                                             25.87  10.19 

Volatile  matter                                                                     37 . 99  45 . 08 

Non-volatile  matter                                                                36.14  44.73 


100.00 


100.00 


400         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

Destructive  Distillation  op  Sludge 

By  raising  the  temperature  of  sludge  sufficiently,  the  organic  constituents  can  be 
volatilized,  leaving  the  residue,  which  is  largely  mineral.  This  treatment  is  carried 
out  at  Oldham  by  a  process  known  as  Watson  and  Butterfield's  Patent  Sludge 
Distilling  Process.  The  sludge  dried  so  as  to  contain  not  over  20  per  cent,  of  water, 
is  put  in  a  retort  and  heated  to  from  1500°  to  1800°  Fahr.  The  volatilized  products 
are  passed  through  a  condenser  and  then  through  a  scrubber  which  extracts  the  mois- 
ture, oil,  tar  and  ammonia.  The  inflammable  gas  which  remains  is  passed  into  the 
combustion  chamber  of  the  retort  and  there  burnt.  Steam  is  blown  into  the  retort, 
near  the  bottom,  and  in  passing  through  the  hot  zone  in  the  retort  it  reacts  on  the  car- 
bonaceous material  in  the  sludge,  and  in  the  presence  of  lime  and  at  the  high  tem- 
perature there  existing,  the  nitrogen  in  the  sludge  is  evolved  as  ammonia. 

The  Royal  Commission  estimate  the  cost  of  pressing  and  burning  sludge  at  Old- 
ham, including  fixed  charges,  at  321/2  cents  per  ton  of  wet  sludge  (containing  90  per 
cent,  of  water)  or,  say,  double  the  cost  of  pressing  alone. 

Production  of  Fertilizer 

Eisner*  gives  the  nitrogen  and  phosphoric  acid  in  sludge  as  each  comprising  about 
1.5  per  cent,  and  the  potash  as  0.5  per  cent,  of  the  dried  material  of  settled  sludge.  He 
estimates  their  theoretical  value  at — 

28  cts.  per  cu.  yd.  of  wet  sludge  (containing  90  per  cent,  water). 
$1.10  per  cu.  yd.  of  dry  sludge  (containing  60  per  cent,  water). 

Eisner  also  estimates  that  sludge  to  the  value  of  $14.30  to  $19.00  per  day  is  produced 
by  every  1,000,000  inhabitants,  but  points  out  that  these  figures  are  only  possible  theo- 
retically. On  the  basis  of  28  cents  per  cubic  yard,  as  above,  and  an  output  of  0.786 
cubic  yards  daily  for  each  1,000  persons,  he  estimates  that  an  annual  revenue  of  $78.50 
could  be  derived  from  the  utilization  of  sludge  which  would  cover  a  part  or,  in  excep- 
tional cases,  perhaps  the  entire  cost  of  operating  a  plant  for  the  production  of 
fertilizer. 

Ammonia  is  usually  the  most  valuable  fertilizing  ingredient,  amounting  to  10 
lbs.  per  capita  per  annum,  worth,  according  to  F.  N.  Taylor,  $1.62. 

Tidy,  quoted  by  Rideal  in  his  "Sewage,"  1901,  estimates  the  value  of  the  components 
of  1,000  long  tons  of  London  crude  sludge  as  shown  in  Table  LXXIX. 
•Sewage  Sludge,  Eisner,  Spillner,  Allen-p.  83. 


UTILIZATION  OP  SEWAGE  401 


TABLE  LXXIX 
Composition  of  Sludge  from  London  Sewage 

Pounds  Price  per  Pound 

Ammonia                                                                       219.37  14.2c. 

Phosphoric  acid: 

Soluble                                                                     27.61  8.1 

Insoluble                                                                   24.20  4.0 

Potash                                                                            50.65  6.1 

Resulting  in  a  total  value  of       cents  per  ton. 


Professor  Robinson,  also  quoted  by  Rideal,  estimates  the  value  of  air-dried  English 
sludge  as  shown  in  Table  LXXX. 


TABLE  LXXX 


Value  of  Aie-Dried  English  Sludge 


Moisture 

Phosphate 
of  Lime 

Nitrogen 

Value  per 
Ton 

Aylesbury  

 1879 

12.60 

4.61 

1.60 

$6.27 

 1879 

13.16 

1.57 

0.49 

2.48 

 1879 

14.34 

1.35 

0.61 

2.90 

 1879 

6.92 

1.59 

0.66 

3.33 

 1879 

10.04 

4.52 

1.27 

5.90 

 1876 

9.56 

1.39 

0.66 

3.08 

 1879 

11.93 

2.64 

1.08 

4.68 

 1877 

11.76 

1.90 

0.52 

2.48 

In  1907  the  Royal  Agricultural  Society  of  England  carried  out  an  extended  series 
of  trials  with  seven  different  kinds  of  partly  dried  sewage  sludge  supplied  them  by 
the  Royal  Commission  on  Sewage  Disposal.  These  experiments  were  continued  for 
two  years.  One  kind  of  sludge  was  compared  with  another  in  growing  wheat  and  these 
were  compared  with  artificial  equivalents  in  the  shape  of  fertilizers.  As  a  result  of 
the  two  years'  work,  substantially  the  following  conclusions  were  reached,  as  stated 
by  Voelcker  in  the  Fifth  Report  of  the  Royal  Commission  on  Sewage  Disposal : 

1.  The  sludges  when  used  so  as  to  supply  40  lbs.  of  nitrogen  per  acre  in- 
creased the  grain  and  straw  of  wheat  10  to  12  per  cent,  above  unmanured 
produce. 

2.  The  increase  will  be  5  or  6  per  cent,  less  than  the  increase  obtained  with 
artificial  equivalents  supplying  the  same  constituents  in  equal  amounts. 

3.  Practically  all  the  benefit  is  imparted  to  the  first  crop  and  little  is  left 
for  a  second. 

4.  The  best  sludges  were  moist  and  contained  much  lime. 

5.  The  nitrogenous  organic  matter  is  not  the  determining  factor  in  the 
value  of  sewage  sludge :  It  is  in  an  inert  condition  which  requires  lime  to  bring 
it  into  action. 


402         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

6.  Two  dollars  and  a  half  per  ton  is  an  outside  figure  for  the  value  on  the 
farm  of  the  sludges  used  (moisture  1.55  to  38.5  per  cent.;  nitrogen  0.53  to 
2.24  per  cent,  and  lime  3.87  to  26.67  per  cent.). 

At  Hanover  and  Harburg  partially  air-dried  sludge  brings  24  cents  for  a  two-horse 
load  or  12  cents  per  cubic  yard  and  at  Unna  septic  sludge  brings  36  cents  per  load. 
Apparently  the  demand  is  not  sufficient  to  take  all  that  is  produced. 

Probably  the  best  form  in  which  to  prepare  sludge  as  a  fertilizer  is  by  drying  and 
grinding  as  practiced  at  Glasgow,  Bradford  and  Kingston. 

At  Glasgow,  Globe  Fertilizer  sells  for  fl.95  to  $2.40  per  ton  in  bulk  or  $3.40  in 
bags,  but  the  demand  does  not  equal  the  supply. 

According  to  the  manufacturer  of  the  dryer  used  at  Bradford,  the  price  of  the 
dried  product  is  $2.17  per  ton  of  material  dried  to  10  per  cent,  moisture,  whereas 
formerly  it  cost  $1.21  per  ton  to  dispose  of  the  cake.  This  cost  was  equivalent  to 
$1.62  per  ton  of  material  with  10  per  cent,  moisture,  making  the  saving  on  38.4  tons 
at  $3.79  ==  $145.54  per  day.  Deducting  $12.94  for  labor  and  fuel,  the  net  profit  from 
drying  appears  to  be  $132.60  per  day  or  $48,000  per  annum.  Table  LXXXI  gives  two 
analyses  of  the  dried  sludge. 

TABLE  LXXXI 
Composition  op  the  Dried  Sludge  at  Bradford 

i  ii 

Per  Cent.  Per  Cent. 

Moisture   10.00  Nitrogen  .   2.61 

Ammonia   2.61  Phosphoric  acid   0.11 

Phosphoric  acid   .31  Potash   0  .31 

Equivalent  of  bone  phosphate   .66 

•    Potash  24 

Grease   14.50 

Non-fertilizing  material   71.68 

100.00 

The  valuations  based  on  these  analyses  were  $6.76  and  $10.79  per  ton,  respectively. 
The  cost  of  preparation  is  roughly  estimated  as  shown  in  Table  LXXXII. 

TABLE  LXXXII 
Cost  of  Preparing  the  Fertilizer  at  Bradford 

Pressing   $0.80 

Drying   40 

Grinding   .15 

Bagging   .15 

Depreciation,  etc   .10 

•  $1.60  per  ton 

The  freight  on  the  material  to  America  is  $3.50  per  ton,  where  it  is  said  to  sell  for 
$5.50  per  ton. 


UTILIZATION  OF  SEWAGE  403 

At  Boston  a  sludge  has  been  obtained  containing  about  23  per  cent,  grease  when 
dried  to  5  per  cent,  moisture.  The  ammonia  amounts  to  about  3  per  cent.  By  ex- 
tracting the  grease  with  naphtha  the  ammonia  content  is  raised  to  about  5  per  cent., 
producing  a  fertilizer  of  value.  A  sample  containing  5.26  per  cent,  was  analyzed  at 
the  Massachusetts  Agricultural  College  and  appraised  at  |16  per  ton. 

At  Norwich,  England,  a  trial  is  being  made  with  the  "Echlenberg"  process  by 
which  the  wet  sludge  is  blown  through  a  3-inch  pipe  located  in  the  center  of  a  5-inch 
pipe.  The  sludge,  introduced  into  the  opposite  end  of  the  larger  pipe  flows  toward 
the  steam  supply  and  is  drawn  through  the  smaller  pipe  with  the  steam  and  is  in  this 
way  heated  nearly  to  the  boiling  point.  It  is  then  readily  pressed  to  50  per  cent, 
moisture  and  dried  in  a  Ruggles-Coles  dryer,  the  product  being  sold  at  about  $3.80 
per  ton. 

In  some  situations  there  is  sufficient  local  demand  to  dispose  of  sludge  cake  to 
farmers  without  cost  and  perhaps  with  a  little  return.  This  is  the  case  at  Glasgow 
and  Bradford.  Eisner  states  that  in  England  18  cents  per  cubic  yard  is  sometimes 
paid  for  its  removal.  At  Halifax,  England,  about  one-tenth  of  the  cake  is  given  away 
and  the  rest  buried  in  the  ground.  At  Bradford,  the  cake  sells  for  74  cents  a  ton, 
rough  ground  cake  for  $1.41  and  fine  ground  material  for  $2.28  a  ton.  At  Spandau 
the  cake  brings  but  5  cents  a  cubic  yard.  At  Manchester,  the  humus  from  contact 
beds  is  dried  on  floors,  ground  and  sold  for  $5.43  per  ton. 

At  Bockenheim,  pulverizing  in  a  rotary  drum  at  212°  Fahr.  and  drying  to  5.15  per 
cent,  moisture  was  tried,  but  the  cost  of  fuel  ($6.48)  per  ton  of  poudrette  was  greater 
than  the  value  of  the  material  itself. 

In  a  general  way  it  may  be  said  that  under  favorable  conditions  as  to  transporta- 
tion a  sludge  containing  50  per  cent,  moisture,  whose  dried  material  contains  3  per 
cent,  of  ammonia  and  less  than  10  per  cent,  grease,  might  be  further  dried,  ground  and 
sold  as  a  filler  for  fertilizer  with  some  slight  profit  in  the  case  of  large  works ;  but  that 
no  other  than  an  occasional  and  uncertain  offset  to  a  part  of  the  cost  of  operation  can 
be  looked  for  even  under  favorable  circumstances  from  the  sale  of  sludge  in  the  form 
of  crude  cake  or  containing  over  30  or  35  per  cent,  of  moisture. 

Mr.  John  D.  Watson,  of  Birmingham,  in  an  address  published  in  the  Surveyor, 
January  9,  1914,  describes  a  process  for  the  concentration  of  sewage  sludge  which  has 
been  experimented  with  at  Dublin,  Ireland,  with  the  object  of  producing  a  fertilizer. 

Brewery  yeast  is  added  to  the  sludge  and  the  latter  is  heated,  whereupon  rapid 
fermentation  occurs  and  the  molecular  condition  of  the  mass  is  changed  so  that  it 
readily  parts  with  its  excess  water.  The  fermentation  takes  place  in  troughs  50  feet 
long  by  4  feet  wide,  holding  about  3,000  gallons  each.    The  sludge  is  heated  before 


404         DATA  RELATING  TO  THE  PROTECTION  OP  THE  HARBOR 

being  delivered  to  these  troughs  and  is  kept  at  a  temperature  of  90°  Fahr.  in  them 
for  24  hours.  After  fermentation,  the  water  is  drawn  off  from  below,  the  sludge  being 
reduced  to  about  one-quarter  of  its  original  volume.  A  compound  of  phosphate  and 
potash  is  then  added,  weight  for  weight,  and  the  mass  is  dried  in  a  cylindrical,  vertical 
casing  containing  a  series  of  arms  and  platforms  revolving  upon  a  center  shaft.  The 
platforms  have  large  perforations  in  the  shape  of  sectors  and  the  mixture,  which  is 
fed  in  at  the  top,  gradually  falls  through  the  drier  to  an  outlet  at  the  bottom.  Air 
at  a  temperature  of  about  450°  Fahr.  is  blown  in  at  the  bottom  and  passes  out  at  the 
top.  The  dried  product  falls  into  a  disintegrator  consisting  of  a  revolving  paddle 
which  beats  up  the  product  into  a  powder  which  is  finally  blown  out  at  one  end  of  the 
machine  by  a  draft  of  hot  air. 

Recovery  of  the  Grease  in  Sludge 

Grease,  while  one  of  the  most  objectionable  ingredients  of  sludge  when  used  as 
fertilizer,  is  one  of  the  most  valuable  when  in  sufficient  quantity  to  warrant  its  extrac- 
tion. The  amount  of  grease  found  in  (German)  sewage  is  estimated  by  Dr.  Beckhold 
quoted  by  Rideal  in  his  "Sewage"  at  8  lbs.  per  capita  each  year.  The  same  author 
states  that  grease  varies  in  sludge  from  3  per  cent,  to  27  per  cent.,  reaching,  in  scum, 
80  per  cent.  In  the  dried  sludge  of  several  German  towns,  it  ranged  from  10  per  cent, 
to  20  per  cent.  The  sludge  from  Emscher  tanks  contains  from  3  per  cent,  to  7  per  cent, 
in  the  case  of  Essen-N.  W.  and  Bochum.  Where  produced  in  large  quantities,  as 
at  slaughterhouses,  restaurants,  wool  scouring  works,  etc.,  it  would  seem  that  the  grease 
could  profitably  be  recovered  at  the  source  and  sold. 

The  works  at  Bradford  furnish  perhaps  the  best  example  of  the  recovery  of  grease. 
The  sewage,  which  is  about  one-tenth  wool-scouring  liquor,  contains  440  parts  per  mil- 
lion of  grease.  The  sludge,  which  contains  7.43  per  cent,  grease,  is  first  treated  with 
sulphuric  acid  and  then  heated  to  about  212°  Fahr.  The  grease  is  mostly  pressed  out 
with  the  hot  press  liquor.  Prom  the  presses,  it  goes  to  separating  vats  where  the 
water  is  drawn  off  from  the  bottom.  Thence  it  passes  to  tanks  where  it  is  boiled 
with  black  oxide  of  manganese  and  sulphuric  acid  or  other  chemicals  and  then,  after 
standing  24  hours,  it  is  barreled  or  else  pumped  to  a  large  storage  vat.  It  is  sold  at 
from  $35  to  $50.50  per  ton. 

For  the  six  months  ending  September  30,  1907,  the  total  cost  of  operation  of  the 
disposal  works,  exclusive  of  the  Chief  Engineer's  salary,  interest  and  sinking  fund, 
was  $48,472,  and  the  receipts  for  grease  and  fertilizer  amounted  to  $57,067,  leaving  a 
net  profit  of  $8,595,  most  of  which  may  be  credited  to  the  sale  of  grease. 

In  Germany  the  extraction  of  grease  was  tried  at  Cassel,  as  stated  by  Eisner  in 


UTILIZATION  OF  SEWAGE  405 

"Sewage  Sludge,"  by  disintegrating  and  drying  the  pressed  cake,  subjecting  it  to  steam 
and  then  extracting  the  grease  by  benzine  in  an  extractor  holding  8yo  cubic  yards. 
The  grease  and  sediment  were  then  separated  from  the  benzine  by  steam  and  the  lat- 
ter condensed  and  used  over.  The  distilled  grease  averaged  15  per  cent,  of  the  dried 
material  in  the  sludge,  which  originally  contained  18  per  cent. 

The  Cassel  plant  cost  $17,600.  Sixty-five  cubic  yards  of  new  sludge  produced  6y2 
cubic  yards  of  dry  sludge,  1,650  lbs.  of  crude  grease  and  990  lbs.  of  refined  grease, 
realizing  $18.20,  aside  from  fertilizer  and  other  products,  which  are  valued  at  about 
$10  more.  The  refined  grease  is  sold  at  4.87  cents  per  pound.  But  in  spite  of  the 
large  return,  the  expenses  were  greater  than  the  receipts.  This  was  due  to  the  first 
cost  of  the  plant,  the  wages  of  the  men  required  and,  especially,  to  the  large  amount 
of  fuel.   After  three  years'  operation  the  plant  was  abandoned. 

From  this  trial  at  Cassel  and  a  similar  unsuccessful  attempt  at  Frankfort,  Eisner 
concludes  that  no  profitable  use  can  be  made  of  benzine.  It  would  be  preferable,  he 
thinks,  to  remove  the  grease  mechanically  from  the  sludge  in  a  Kremer  tank.  When 
the  grease  is  first  removed  in  a  Kremer  tank,  it  contains  72  per  cent,  moisture  and  the 
dried  material  contains  15  per  cent,  grease.  The  product  is  placed  in  a  perforated 
vessel  for  further  drying  and  is  then  ready  for  the  market. 

Eisner  further  concludes  that  a  plant  for  this  purpose  is  only  warranted  for 
towns  having  at  least  15,000  inhabitants,  while  Spillner  holds  out  the  hope  of  a  pos- 
sible profit  only  in  those  cases  where  the  percentage  of  grease  in  the  dried  sludge  is 
above  15  per  cent. 

Grease  from  the  Kremer  apparatus  at  Charlottenburg  is  treated  with  bisulphate 
of  potassium,  charcoal  and  common  salt  and  then  cooked  with  steam.  The  clarified 
fat  rises  and  the  residue  is  disposed  of  with  the  sludge  from  the  plant. 

If  the  recovery  of  grease  is  attempted,  its  extraction  from  the  sewage  should  be 
as  complete  as  practicable.  In  this  way  it  may  be  possible  to  make  the  process  re- 
munerative by  the  use  of  certain  precipitants  when  it  would  not  be  so  with  others. 
Sulphuric  acid  has  been  mentioned  in  this  connection  as  promoting  precipitation  of 
the  dissolved  or  emulsified  fats  and  yet  at  Bradford  there  remains  14!/2  per  cent,  of 
grease  in  the  fertilizer  containing  10  per  cent,  moisture.  The  grease  is  a  detriment  to 
its  use  as  a  fertilizer  as  well  as  a  direct  loss  of  an  otherwise  valuable  product. 

Experiments  which  have  been  carried  on  at  the  Boston  Drainage  Works  indicate 
that  by  the  use  of  sulphur  dioxide,  the  dissolved  grease  is  "cracked"  or  coagulated  and 
so  made  recoverable  much  more  completely  than  in  any  other  way.  This  treatment, 
moreover,  renders  the  effluent  practically  odorless  and  sterile. 

Aside  from  its  intrinsic  value,  the  removal  of  grease  is  desirable  in  those  cases 


406 


DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


where  sludge  is  to  be  pressed,  where  it  is  to  be  used  as  fertilizer,  where  it  is  to  be 
dried  and  in  those  cases  where  the  sewage  is  to  be  distributed  by  sprinklers.  The 
benefits  derived  from  its  removal  may  properly  be  added  to  the  return  from  the  sale 
of  grease  in  judging  the  economy  of  the  entire  treatment. 

The  Use  op  Sludge  as  Fuel 

Sludge  after  being  dried  has  a  certain  value  as  fuel,  depending  on  its  original 
character  and  treatment  which  it  has  received.  The  percentage  of  moisture  which  the 
sludge  contains  is  an  important  element  in  determining  its  value.  If  this  is  much 
over  70,  combustion  is  not  practicable  and  the  expense  of  artificial  drying  below  50 
per  cent,  is  not  warranted  unless  for  considerations  relative  to  transportation  or 
preparation  in  a  marketable  form. 

The  British  thermal  units  developed  by  the  burning  of  sludge  from  various  cities 
are  stated  in  Table  LXXXIII. 

TABLE  LXXXIII 
Heat  Units  Developed  from  Burning  Sludge 

SLUDGE  FROM  PLAIN  PRECIPITATION 

Stuttgart   47%    moisture   8,035  British  thermal  units 

Hanover   28%     ash  :   15,870  British  thermal  units 

Hanover   18^%  ash  17,120  British  thermal  units 

Experiments  at 

Philadelphia   51 .8%  moisture   3,768  British  thermal  units 

Philadelphia   34 . 8  %  volatile  

Experiments  by 

Bredtschneider  and  Proskauer. .  .  20%    volatile   8,730  British  thermal  units 

Bredtschneider  and  Proskauer. . .  30%    combustible  material .... 

SLUDGE  FROM  SEPTIC  TREATMENT 
Stuttgart   40%    moisture   6,456  British  thermal  units 

SLUDGE  FROM  LIGNITE  PROCESS 

Potsdam   60%     moisture   5,950  British  thermal  units 

Copenick   40%    moisture   8,630  British  thermal  units 

Experiments  on  the  combustion  of  sludge  mixed  with  pea  coal  were  made  in 
Philadelphia  with  the  results  stated  in  Table  LXXXIV,  taken  from  the  Report  of 
the  Sewage  Testing  Station,  1911.    The  coal  contained  12,065  b.  t.  u. 


TABLE  LXXXIV 
Results  Attained  on  Burning  Sludge  and  Coal 


Sludge 


Coarse 
Particles 
Removed 


Complete 
Sample 


Partly 
Digested 


Partly 
Digested 


British  thermal  units  as  burnt  

Pounds  per  cubic  yard,  broken  

Percentage  moisture  

Percentage,  dry  residue,  volatile. .  . . 
Pounds  of  coal  burnt,  per  pound  of: 

Wet  Sludge  

Dry  residue  

Volatile  matter  


1877 
1015 

32.2 

30 


2165 
835 
40.2 
28.3 


.83 

.817 

.246 


.68 

.875 

.25 


1216 
840 
35.8 
29.2 

.75 
.86 
.25 


1360 
710 
15.3 
24.5 


.895 
.945 
.233 


UTILIZATION  OF  SEWAGE 


407 


At  Worcester  experiments  were  made  in  1891  in  which  45  tons  of  sludge,  con- 
taining 46  per  cent,  water,  were  burned  with  three  cords  of  wood  at  a  total  cost  of  $3 
per  ton  of  dry  solids ;  the  cost  was  chiefly  due  to  the  handling  of  the  material.  Sludge 
with  72  per  cent,  water  was  burned  at  the  rate  of  .24  tons  per  hour  with  very  little 
fuel. 

Kinnicutt,  Winslow  and  Pratt  in  the  "Sewage  Disposal"  conclude  that  if  sludge 
contains  60  per  cent,  or  less  moisture,  it  may  be  burned,  and  that  even  with  72  per 
cent,  moisture,  burning  is  possible  if  great  care  is  exercised. 

Sludge  dried  to  10  or  20  per  cent,  moisture  can  be  briquetted  and  in  this  condi- 
tion it  can  be  transported  readily  as  fuel.  At  Bradford  a  briquetting  machine  has 
recently  been  installed  by  which  the  sludge  not  sold  as  fertilizer  may  be  treated  in 
this  way.  The  machine  has  a  capacity  of  five  long  tons  per  hour  and  requires  about 
20  HP.  to  operate.  No  binder  is  required,  possibly  due  to  the  fact  that  a  consider- 
able percentage  of  grease  still  remains  in  the  dry  sludge. 

Sludge  produced  by  the  lignite  process  is  well  adapted  to  utilization  as  fuel.  With 
the  use  of  from  4  to  8  tons  of  lignite  per  million  gallons  of  sewage,  the  pressed  cake  is 
combustible.  The  lignite  process,  therefore,  while  costly  in  operation  has  this  possi- 
bility of  a  partial  financial  compensation  beside  producing  a  very  clean  effluent. 

A  moderate  amount  of  coal  may  profitably  be  added  to  ordinary  partially-dried 
sludge  for  use  under  boilers.  This  was  tried  at  Bradford,  using  one  part  of  coal  with 
seven  parts  of  pressed  cake  and  with  forced  draught.  It  was  estimated  that  $4,760 
was  saved  in  one  year  by  this  practice. 

At  Huddersfield  the  Fifth  Report  of  the  Royal  Commission  on  Sewage  Disposal 
states  that  one  part  of  coke  breeze  was  mixed  with  five  parts  of  sludge  cake  and  burned 
at  a  cost  of  56  cents  per  ton.   The  cost  follows: 


The  process  was  found  costly,  but  the  sludge  was  finally  disposed  of.  Its  calo- 
rific value  was  certainly  considerable  and  the  clinker  produced  was  a  further  asset. 

At  Ealing  sludge  was  formerly  first  mixed  with  two  volumes  of  refuse  and  then 
burned  with  four  additional  volumes  of  refuse.  More  recently  the  sludge  pressed  to 
60  per  cent,  moisture  has  been  mixed  and  burned  with  1%  to  2  parts  of  refuse  at  a 
cost  of  from  36  to  40  cents.  This  cost  is  recovered  by  the  sale  of  clinker,  leaving  a 
margin  of  steam  for  power  according  to  Kinnicutt,  Winslow  and  Pratt  in  their  work 
on  "Sewage  Disposal." 

At  Bury  from  67  to  78  tons  of  cake  mixed  with  twice  that  amount  of  refuse  daily 
was  burned  under  boilers  and  furnished  38  HP.  besides  which  the  clinker  was  util- 


Coke  breeze 

Stokers  

Mixers  


33  He 
13c. 
9Mc 


408         DATA  RELATING  TO  THE  PROTECTION  OP  THE  HARBOR 

ized.  At  Charlottenburg  one  part  of  sludge  with  75  per  cent,  moisture  mixed  with 
three  parts  of  refuse  evaporated  from  0.67  to  1.08  lbs.  of  water  per  pound  of  mixture 
when  burned  under  boilers. 

It  would  appear  from  the  experience  cited  above  that  if  no  more  profitable  use 
can  be  made  of  partially  dried  sludge  than  depositing  in  dumps,  as  is  frequently  done, 
there  will  be  a  probable  saving  in  burning  it  under  boilers  with  coal.  If  a  refuse 
destructor  is  accessible,  then  it  may  very  well  be  mixed  with  the  refuse  and  consumed. 
In  exceptional  cases,  as  where  containing  lignite  which  has  been  used  as  a  precipitant 
or  where  the  sewage  contains  much  coal  from  mine  wastes,  the  recovery  of  the 
calorific  value  will  be  yet  more  profitable.  If  the  sludge  contains  much  grease  this 
should  first  be  separated  out,  both  for  its  own  value  and  to  improve  the  remaining 
sludge  for  use  as  fuel. 

Production  op  Gas  from  Sludge 

Gases  Produced  by  Decomposition.  When  sludge  is  allowed  to  decompose  in  the 
absence  of  oxygen,  as  in  a  septic  or  Emscher  tank,  large  quantities  of  inflammable 
gas  are  produced.  The  gas  is  a  mixture  of  methane,  nitrogen,  carbon  dioxide  and 
various  other  ingredients.  The  composition  varies  greatly  and  the  quantity  of  gas 
given  off  depends,  in  large  measure,  upon  the  temperature  of  the  sludge. 

It  has  been  suggested  that  the  gases  be  recovered  and  utilized  but  no  works  have 
as  yet  been  built  to  carry  out  this  idea.  It  would  appear  that  its  feasibility  was  most 
promising  in  the  tropics. 

According  to  Rideal,  the  chemical  processes  which  take  place  in  the  septic  tank 
are  as  follows : 

1.  An  hydrolysis  of  complex  albuminous  bodies  which  takes  place  in  two 
stages:  (a)  conversion  to  a  soluble  form,  peptonization;  (b)  hydrolysis  of  the 
peptones  into  amino  acids,  leucin,  tyrosin  and  aromatic  bodies.  This  process 
involves  no  gas  formation. 

2.  Splitting  up  the  amino  acids  into  fatty  or  aromatic  acids,  with  the  for- 
mation of  ammonia  or  nitrogen  or  both  together. 

3.  The  acids  formed  by  the  split  of  the  albumin  molecules  break  down  into 
still  simpler  acids.    In  this  process  hydrogen  and  methane  are  generated. 

4.  The  hydrolysis  of  urea  to  carbon  dioxide  and  ammonia,  which  unite  to 
form  ammonium  carbonate. 

5.  The  decomposition  of  cellulose  into  fatty  acids  and  carbon  dioxide  with 
the  evolution  of  hydrogen  or  methane. 

6.  The  hydrolysis  of  starches,  sugars  and  gums  to  butyric  and  lactic  acids 
with  the  formation  of  carbon  dioxide,  hydrogen  and  water. 


UTILIZATION  OF  SEWAGE 


409 


7.  The  decomposition  of  fats.    This  is  practically  nil  under  anaerobic 
conditions. 

8.  The  formation  under  the  influence  of  bacteria  of  hydrogen  sulphide  and 
mercaptans  from  the  sulphur  in  the  organic  molecule. 

Carbon  dioxide  results  from  the  breaking  down  of  organic  acids  and  the  decom- 
position of  the  cellulose  and  carbo-hydrates.  It  varies  greatly  in  amount,  ranging 
from  practically  0  to  over  50  per  cent,  of  the  total  amount  of  gas,  with  an  average 
percentage  apparently  of  less  than  20. 

The  methane  is  sometimes  over  90  per  cent,  of  the  total  amount  of  gas,  the  usual 
proportion  being  about  70  or  80  per  cent.  The  quantity  of  sulphuretted  hydrogen  is 
very  small ;  there  is  frequently  a  total  absence  of  this  offensive  odor.  There  is  usually 
a  trace  of  oxygen  present  and  a  small  amount,  usually  less  than  1  per  cent,  of  a  gas 
which  is  absorbed  by  Cu2  CH2  and  has  frequently  been  taken  for  carbon  monoxide. 
Blood  spectrum  and  iodine  pentoxide  tests  made  by  Jesse  in  a  systematic  examina- 
tion of  the  gases  produced  by  septic  tanks  in  Illinois  led  to  the  opinion  that  this  gas 
was  not  carbon  monoxide.  Its  identity  remains  unknown.  There  appears  to  be  little 
or  no  ammonia  produced.  A  considerable  amount  of  nitrogen  is  usually  given  off. 
The  amount  may  be  as  great  as  60  per  cent,  or  more,  but  is  usually  between  5  and  30 
per  cent. 

Table  LXXXV,  prepared  from  data  collected  by  Jesse,  gives  a  considerable  num- 
ber of  analyses  of  gas  from  septic  tanks  and  Emscher  tanks.  The  results  given  are 
stated  as  percentages. 

TABLE  LXXXV 


Gases  fkom  Sewage  Tanks 


Town 

COj 

0, 

Gas 
Absorbed 
by 
Cu2Cl2 

CH4 

Nj 

H,S 

Urbana  (averages  of  12  samples)  

12.28 

.13 

.45 

81.02 

6.14 

Champaign  (averages  of  3  samples)  

27.23 

.06 

.08 

72.18 

.45 

Highland  Park: 

Tank  A  

12.18 

.0 

.32 

79.77 

7.72 

Tank  B  (averages  of  4  samples)  

13.93 

.35 

.11 

84.20 

.99 

Tank  C  (averages  of  2  samples)  

20.3 

.0 

.0 

73.96 

5.73 

Chicago : 

Tank  A,  open  septic  

8.60 

.0 

.30 

84.92 

6.18 

Tank  B,  closed  septic  (averages  of  2  samples)  

6.08 

.16 

.34 

83.6 

9.7 

.06 

Tank  C  

9.31 

.62 

.45 

83.9 

5.72 

Dortmund  Tank  

6.42 

.30 

.0 

60. 

33.06 

.22 

Winnetka  (averages  of  3  samples)  

9.35 

.0 

.44 

87.12 

3.09 

Lake  Forest  (averages  of  2  samples)  

8.5 

.24 

.65 

87.78 

2.76 

Woodstock  (averages  of  3  samples)  

15.14 

.08 

.58 

81.79 

2.41 

Downers  Grove  (averages  of  3  samples)  

19.83 

.04 

.41 

79.72 

.003 

LaG  range  

7.31 

.0 

.37 

80.81 

11.51 

Naperville  (averages  of  3  samples)  

15.43 

.24 

.41 

76.56 

7.37 

Wheaton  

9.33 

.0 

.72 

82.10 

7.85 

.04 

DeKalb  (averages  of  4  samples)  

28.45 

.04 

.70 

70.41 

.40 

Collinsville: 

16.53 

.22 

.38 

80.27 

2.37 

.20 

Tank  II  

9.46 

.09 

.65 

86.00 

3.80 

Edwardsville  

11.33 

.15 

.21 

87.34 

.97 

410         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

The  decomposition  of  sludge  at  the  bottom  of  rivers  produces  gases  which  do  not 
differ  materially  from  those  which  are  produced  by  the  putrefaction  of  sludge  in 
tanks. 

Following  are  the  results  of  analyses  of  gases  collected  from  the  New  York  harbor 
and  examined  for  the  Metropolitan  Sewerage  Commission. 

TABLE  LXXXVI 

Gases  Collected  from  the  Heavily  Polluted  Parts  of  New  York  Harbor  and 

Examined 


August  11,  1911 


CO, 

0, 

CH4 

N, 

5.2 

0.1 

89.8 

4.6 

October  31,  1911 

East  109th  Street,  Harlem  

7.6 

0.2 

85.4 

6.8 

East  of  Degraw  Street  

1.8 

2.4 

82.1 

13.7 

East  24th  Street  

2.4 

1.3 

83.3 

13.0 

4.2 

0.4 

86.7 

8.7 

11.5 

0.4 

84.8 

3.3 

Recovery  for  Utilization.  Besides  grease,  sludge  yields  appreciable  volumes  of 
other  materials  in  the  gaseous  form  on  distillation.  In  1910  the  Massachusetts  State 
Board  of  Health  published  the  components  found  on  the  destructive  distillation  of 
400  grams  of  different  kinds  of  dried  sludge  as  stated  in  Table  LXXXVII. 

TABLE  LXXXVII 


Gas  Produced  from  the  Destructive  Distillation  of  Sludge 


Source 

Cubic  Feet 
Gas,  per  Ton 

Per  Cent. 

of  Sample 

CO, 

IUuminant 

O 

CO 

H 

CH4 

N 

Lawrence  sludge*  

Andover  sludge*  

Clinton  sludge*  

4,900 

4.4 

2.2 

0.3 

30.7 

34.9 

18.6 

9.1 

6,400 

7.4 

15.1 

0.6 

14.3 

22.9 

34.3 

5.4 

9,100 

8.3 

6.7 

0.0 

20.4 

33.2 

24.5 

7.0 

Brockton  sludge*  

6,000 

16.5 

21.4 

0.2 

10.3 

22.6 

29.1 

0.2 

Worcester  sludge  f  

8,100 

14.2 

4.9 

0.3 

29.8 

32.6 

16.2 

2.2 

Septic  tank  sludge  

4,900 

7.5 

1.9 

0.1 

24.3 

44.0 

13.0 

10.2 

Trickling  filter  sludge  

6,000 

20.2 

17.4 

0.3 

6.6 

32.7 

22.8 

0.0 

Illuminating  gas  

3.4 

9.1 

0.0 

21.5 

42.5 

19.7 

3.8 

*Plain  settled. 
fChemically  precipitated. 


UTILIZATION  OF  SEWAGE  411 

The  calorific  value  of  sludge  depends  to  a  large  extent  on  the  moisture  contained 
in  it;  the  moisture  has  to  be  evaporated  before  the  more  valuable  constituents  can  be 
recovered. 

Eisner  in  "Sewage  Sludge"  gives  the  calorific  value  of  the  dried  material  of  sludge 
as  about  7,200  b.t.u.  per  pound  and  then  proceeds  to  show  how  many  heat  units  must 
be  absorbed  in  the  distillation  of  sewages  with  different  degrees  of  moisture  before 
the  7,200  units  can  be  realized.   His  figures  are  contained  in  Table  LXXXVIII. 

TABLE  LXXXVIII 


Heat  Units  Absorbed  in  Converting  the  Moisture  of  Sludge  to  Steam 


Per  Cent.  Moisture 

British  Thermal  Units 
to  Convert  to  Steam 

Per  Cent.  Moisture 

British  Thermal  Units 
to  Convert  to  Steam 

10  

126.7 
288.0 
495.4 
771.8 
1,152.0 

60  

1,728.0 
2,684.2 
4,608.0 
4,608.0 

20  

70  

34  

80  

40  

90  

50  

From  this  Spillner  concludes  that  unless  it  is  first  reduced  to  80  per  cent,  mois- 
ture, sludge  has  no  practical  calorific  value  and  that  if  it  is  dried  artificially,  there 
will  be  little  gain  in  carrying  this  reduction  beyond  50  or  60  per  cent,  moisture. 

Experiments  have  been  made  at  Oberschoneweide  in  which  5.63  to  8.23  tons  of 
lignite  with  0.75  to  1.13  tons  of  sulphate  of  alumina  were  used  per  million  gallons  of 
sewage.  It  furnished  12.5  tons  of  sludge  64  per  cent,  moisture  with  a  calorific  value 
of  3,202  b.t.u.  This  was  air-dried  to  51  per  cent,  moisture  for  it  was  shown  that  when 
the  sludge  contained  as  much  as  58  per  cent,  moisture,  conversion  to  gas  was  not 
practicable.   The  results  were  as  shown  in  Table  LXXXIX. 

TABLE  LXXXIX 
Gases  in  Sludge  Treated  with  Chemicals 

Carbon   22.3%  Oxygen   12.8% 

Hydrogen   2.7  Sulphur   0.5 

Nitrogen   1.0  Ash   9.8 

The  calorific  value  per  1,000  cu.  ft.  of  the  gas  was  81,000  b.t.u.  By  the  use  of 
this  gas  in  a  gas  engine  the  cost  of  operation  of  the  clarification  plant  was  reduced 
from  33.1  to  24.5  cents  per  capita  per  annum  or  by  fl6.20  per  million  gallons  of 
sewage,  including  fixed  charges. 

In  general  it  may  be  said  that  little  has  been  done  in  the  way  of  utilizing  the  gas 
from  sludge  either  for  illumination  or  power.   The  Massachusetts  experiments  showed 


412         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

a  great  variation  in  the  composition  of  sludge  of  different  towns.  The  sludge  from 
Andover,  Brockton  and  trickling  filters  was  high  in  value  as  an  illuminant,  while  that 
from  Lawrence,  Worcester  and  septic  tanks  was  low. 

It  is  probable  that  although  the  digested  sludge  is  not  valuable  for  gas  produc- 
tion, the  gas  evolved  from  septic  or  Emscher  tanks  might  in  large  installations  be 
utilized  for  either  light  or  power  in  the  neighborhood  of  the  plant. 

Experiments  in  the  distillation  of  gas  for  power  from  sludge  have  been  mostly 
confined  to  Germany  and  the  results  obtained  have  not  given  promise  of  any  great 
pecuniary  benefit  to  be  derived  unless  under  such  special  conditions,  as  when  the 
sludge  contains  coal  dust,  lignite  or  other  material  of  high  calorific  value. 

Financial  Results 

A  general  review  of  the  attempts  that  have  thus  far  been  made  to  utilize  sludge 
do  not  encourage  the  belief  that  any  great  profit  can  be  derived,  except  in  cases  where 
the  nitrogen  or  fats  are  abnormally  high.  Under  other  conditions,  past  attempts  to 
secure  anything  more  than  a  nominal  revenue  have,  as  a  rule,  resulted  in  failure.  The 
crux  of  the  problem  is  the  separation  of  the  water  and  the  concentration  of  the  valu- 
able ingredients.  This  is  necessarily  costly,  whether  done  mechanically  or  by  the  direct 
action  of  heat. 

The  cost  of  pressing  sludge  so  that  its  moisture  is  reduced  from  95  per  cent,  to  55 
per  cent,  is  shown  in  Table  XC. 


TABLE  XC 
Cost  of  Pressing  Sludge 


Large  Towns 

Small  Towns 

Per  Ton 

Per  Ton 

Per  Ton 

Per  Ton 

Wet  Sludge 

Pressed  Cake 

Wet  Sludge 

Pressed  Cake 

$0.10 

$0.50 

$0.23 

$1.00 

The  cost  of  drying  from  90  per  cent,  to  60  per  cent,  by  centrifugal  machines 
amounts  to  about  10  cents  per  cubic  yard  of  wet  sludge  or  45  cents  per  cubic  yard  of 
product. 

The  further  drying  from  60  per  cent,  to  10  per  cent,  moisture  by  rotary  dryers 
may  cost  75  cents  per  ton  of  dried  material. 


UTILIZATION  OF  SEWAGE  413 

The  revenue  to  be  derived  from  the  sale  of  dried  sludge  as  fertilizer  and  from 
grease  will,  in  many  eases,  more  than  offset  the  cost  of  production,  in  large  towns,  be- 
sides furnishing  a  sanitary  and  inoffensive  method  of  disposing  of  sludge. 

The  drying  of  sludge  for  fertilizer  and  the  extraction  of  the  contained  grease 
offer  a  more  promising  outlook  than  others.  In  many  works  where  it  would  not  be 
worth  while  to  undertake  these  somewhat  elaborate  processes,  it  will  be  found  of  ad- 
vantage to  dispose  of  the  semi-dried  centrif uged  or  pressed  sludge  to  farmers  for  what 
it  will  bring  or  else  burn  it  under  the  boilers  of  the  plant. 


CHAPTER  II 


PRINCIPLES  OF  MAIN  DRAINAGE  AND  SEWAGE  DISPOSAL  APPLI- 
CABLE TO  NEW  YORK,  WITH  EXAMPLES  DRAWN 
FROM  VARIOUS  LARGE  CITIES 

MAIN  DRAINAGE 

By  main  drainage  is  meant  an  arterial  sewerage  system  whose  function  it  is  to  col- 
lect the  sewage  of  one  or  more  local  sewerage  systems  and  carry  it  to  one  or  more  cen- 
tral points  for  final  disposition. 

Main  drainage  is  contrasted  with  local  drainage  chiefly  in  its  ultimate  object. 
Whereas  the  purpose  of  main  drainage  is  to  protect  the  rivers,  lakes  and  harbors  upon 
which  cities  are  situated,  the  object  of  local  drainage  is  to  remove  the  sewage  of  the 
houses  and  streets  from  its  immediate  points  of  origin.  Local  sewers,  as  ordinarily 
built,  may  pollute  the  natural  waterways.  With  main  drainage  these  natural  bodies 
of  water  can  be  kept  reasonably  clean. 

The  sewage  which  is  collected  by  a  main  drainage  system  must,  of  necessity,  be  dis- 
charged somewhere,  and  to  prevent  excessive  pollution  at  the  point  of  outfall,  it  is 
often  desirable  and  usually  feasible  to  pass  the  sewage  through  some  process  of  puri- 
fication before  the  final  discharge  takes  place.  The  method  of  disposal  which  it  is  best 
to  employ,  like  the  system  of  main  drainage  which  is  tributary  to  it,  depends  upon 
various  conditions,  including  the  quantity  of  sewage  and  the  facilities  which  exist 
for  the  discharge  of  the  effluent. 

Some  of  the  engineering  principles  upon  which  a  system  of  main  drainage  is  con- 
structed are,  in  many  respects,  the  same  as  those  upon  which  local  sewerage  systems 
are  based.  In  each  case  the  sewage  generally  flows  in  closed  conduits  which  are  built 
large  enough  to  accommodate  the  greatest  flow  of  sewage  which  is  expected.  The  cur- 
rents are  maintained  by  gravity  and  the  gradients  upon  which  the  sewers  are  laid  are 
such  as  are  intended  to  insure  rates  of  flow  sufficiently  rapid  to  prevent  deposits  taking 
place.  In  many  instances  catch-basins,  screens  and  other  forms  of  apparatus  are  pro- 
vided, in  order  to  permit  the  removal  of  solid  matters  which  would  interfere  with  the 
flow  of  the  sewage  or  with  the  operation  of  pumps.  Other  appurtenances  commonly 
employed  are  pumps  to  raise  the  sewage,  regulators  to  deliver  into  the  main  drainage 
system  that  part  of  the  sewage  which  it  is  intended  to  carry  and  divert  the  excess  to 
storm  overflows,  and  tide-gates,  whose  duty  it  is  to  exclude  tidal  water. 


MAIN  DRAINAGE  415 

Practically  all  main  drainage  works  operate  in  connection  with  local  sewerage 
systems  built  upon  the  combined  plan.  The  collection  of  house  sewage  and  storm 
water  in  separate  systems  of  conduits  is  practiced  in  very  few  large  cities. 

Terms  and  Assumptions  Used  by  the  Commission 

In  the  studies  of  the  Commission  various  terms  have  been  employed  to  describe 
the  types  of  sewers  used  in  the  main  drainage  works,  and  the  meaning  which  has  been 
attached  to  these  terms  has  been  always  the  same.  Sewers  running  parallel  to  the 
shore  line  and  intended  to  intercept  the  flow  of  sewage  from  the  local  sewers  have 
been  termed  interceptors.  Sewers  which  have  penetrated  for  a  considerable  distance 
inland  to  collect  the  sewage  from  a  territory  not  adjacent  to  the  harbor  have  been 
called  collectors.  Sewers  extending  from  pumping  stations  to  more  or  less  distant 
points  and  intended  to  carry  the  sewage  from  one  place  to  another  without  receiving 
additions  on  the  way  have  been  called  mains,  whether  operated  under  pressure  or  by 
gravity.  Siphons  are  deep-lying  sewers  usually  extending  under  some  part  of  the  har- 
bor and  intended  to  carry  the  sewage  under  an  obstacle.  Marginal  sewers  are  rela- 
tively short  interceptors  near  the  waterfront  connected  with  larger  near-lying  inter- 
ceptors in  the  same  territory.  No  distinction  has  been  made  between  sewers  built  as 
tunnels  and  in  open  cut,  the  method  of  excavation  being  of  no  importance  in  the  final 
works. 

The  term  district  has  been  restricted  by  the  Commission  to  the  metropolitan  sew- 
erage district  of  New  York  and  New  Jersey,  which  is  the  territory  laid  out  by  the  Com- 
mission in  1908  for  the  purpose  of  its  studies.  A  description  of  the  metropolitan 
district,  its  distinctive  topographical  characteristics,  population,  industries  and  the 
increasing  pollution  of  its  waters  were  described  in  the  report  of  the  Commission, 
April  30,  1910,  Part  II,  Chapter  I,  page  51  and  following. 

The  term  division  has  been  used  by  the  Commission  to  indicate  one  of  the  four 
principal  parts  into  which  the  City  of  New  York  was  separated  in  these  studies  for 
the  purpose  of  working  out  the  general  principles  of  main  drainage  and  sewage  disposal 
which  were  most  applicable  to  the  situation.  A  subdivision  was  a  smaller  part  into 
which  a  main  division  was  separated.  The  divisions  have  been  known  by  the  waters 
to  which  their  drainage  areas  were  naturally  tributary.  The  subdivision  was  described 
by  its  location,  by  the  name  of  some  well-known  locality  or,  where  the  subdivisions 
were  very  numerous,  by  a  number,  the  location  of  which  could  easily  be  ascertained. 

Drainage  area  has  meant  natural  drainage  area  and  not  the  territory  which,  by 
pumping  or  other  means,  could  be  made  tributary  to  a  single  sewer  outlet  or  group  of 
outlets. 


416         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

Sewage  has  included  the  drainage  of  houses,  streets  and  industrial  establishments, 
such  as  contribute  to  the  flow  of  sewage  in  the  combined  sewers  of  New  York  City. 
Where  the  drainage  of  houses  has  alone  been  considered,  the  term  domestic  sewage  or 
house  sewage  has  generally  been  employed.  The  term  sanitary  sewers  or  sanitary  sew- 
age has  never  been  employed  in  the  reports  of  the  Commission. 

The  evidences  of  pollution,  whether  recognizable  to  the  senses  or  detectable  by 
analyses  have  rarely  been  referred  to  in  the  Commission's  reports  as  sewage.  Seivage 
matter  or  sewage  materials  or  organic  matter  have  generally  been  employed  to  indicate 
the  contaminating  substances,  whether  solid  or  liquid. 

In  referring  to  methods  of  disposal,  the  term  purification  has  been  used  sparingly 
to  indicate  practically  all  methods  by  which  sewage  may  be  more  or  less  completely 
relieved  of  its  harmful  and  offensive  properties.  The  production  of  an  absolutely  pure 
effluent  has  not  been  thought  to  be  necessary  in  employing  this  term.  Seicage  treat- 
ment is  a  synonym  of  purification,  the  difference  in  meaning  being  slight  and  relatively 
unimportant,  so  far  as  the  Commission's  reports  have  been  concerned.  By  submerged 
outlets  the  Commission  has  meant  pipes  or  other  structures  intended  to  discharge  sew- 
age at  the  bottom  of  the  harbor.  Surface  water  is  water  near  the  top  in  the  harbor 
and  not  the  actual  surface. 

Local  sewers  are  often  built  by  cities  in  a  piecemeal  manner  and  with  little  or  no 
consideration  for  the  need  of  co-ordinating  the  various  outlets.  In  a  city  such  as  New 
York,  with  several  hundred  outlets,  it  may  be  said  that  several  hundred  local  sewerage 

systems  exist. 

In  course  of  time  the  independent  outlets  require  to  be  wholly  or  partly  eliminated 
and  the  unrelated  sewerage  systems  made  tributary  to  a  comprehensive  main  drainage 
system.  Where  careful  scientific  design  forms  the  basis  of  the  main  drainage  works, 
the  sewage  will  not  only  be  carried  away  to  the  best  advantage,  but  a  sanitary  disposi- 
tion will  be  accomplished  at  a  minimum  of  cost,  obsolete  methods  will  be  avoided  and 
haphazard  work  will  be  prevented. 

The  quantities  of  sewage  to  be  provided  for  in  the  plans  which  the  Commission 
has  made  for  the  main  drainage  of  New  York  have  been  based  upon  estimates  of  pop- 
ulations and  allowance  of  per  capita  production  of  sewage  per  24  hours. 

The  population  has  been  the  subject  of  long-continued  study.  A  discussion  of 
this  subject  will  be  found  in  the  report  of  the  Commission  of  April,  1910,  Part  III, 
Chapter  II,  page  133  and  following.  Where  the  most  accurate  estimates  practicable 
have  been  necessary  for  certain  areas,  the  Commission  has  proceeded  as  follows:  The 
latest  census  returns  have  been  plotted  upon  a  map,  using  the  smallest  political  divi- 


MAIN  DRAINAGE  417 

sions  included  in  the  census  as  the  boundaries  within  which  the  data  were  included. 
Dots  made  with  inks  of  different  colors  were  used  to  represent  units  of  500,  1,000  and 
5,000  of  the  population,  the  distribution  of  the  dots  within  the  area  being  based  upon 
personal  judgment  resting  upon  familiarity  with  the  neighborhood.  The  number  and 
color  of  the  dots  thus  found  to  be  contained  within  a  drainage  area  have  been  taken  to 
indicate  the  number  of  persons  whose  sewage  was  tributary  to  the  sewers  whose  flow 
was  to  be  estimated.  Allowance  was  made  for  transitory  population  in  those  parts  of 
the  city  wherein  this  factor  seemed  likely  to  play  a  considerable  part. 

The  per  capita  allowance  of  sewage  derived  from  the  public  water  supply  was 
based  largely  upon  information  obtained  from  the  authorities  in  charge  of  the  public 
Avater  supply.  The  average  production  per  capita  per  day  for  the  several  boroughs 
has  been  taken  at  160  gallons  for  Manhattan  and  125  gallons  for  the  other 
boroughs.  It  has  been  assumed  that  one-half  the  total  quantity  of  domestic  sewage 
would  flow  off  in  eight  hours,  which  is  equivalent  to  a  maximum  rate  of  50  per  cent,  in 
excess  of  the  average  rate.  The  maximum  rates  then  are  240  gallons  for  Manhattan 
and  187.5  gallons  for  Brooklyn,  Bronx,  Queens  and  Richmond. 

The  trade  wastes  were  allowed  for  in  the  per  capita  volume  of  domestic  sewage  on 
the  assumption  that  the  volume  of  water  becoming  trade  wastes  over  and  above  that 
secured  from  the  water  supply  would  be  balanced  by  the  loss  of  water  from  the  water 
supply  which  did  not  reach  the  sewers. 

From  measurements  made  on  maps  of  the  Boroughs  of  Manhattan,  The  Bronx, 
Brooklyn  and  Queens,  it  was  found  that  there  were  on  an  average  from  about  26  to 
28.5  miles  of  streets  measured  on  the  center  lines  per  square  mile  of  area  of  built-up 
district.  With  each  street  sewered  and  making  a  deduction  for  length  of  sewers  not 
carried  across  intersections,  it  was  considered  reasonable  to  assume  the  length  of 
sewers  to  be  25  miles  per  square  mile  in  built-up  districts  and  15  miles  in  suburban 
districts. 

The  leakage  into  the  sewers  was  assumed  at  a  maximum  of  30,000  and  an  average 
of  15,000  gallons  per  mile  of  sewers  per  24  hours. 

Combining  these  leakages  with  the  lengths  of  sewers  the  following  assumptions 
for  the  leakage  per  square  mile  of  area  were  arrived  at. 


Character  of  district 

Miles  of  sewers 
per  square  mile 
of  area 

Leakage  into  sewers 
Gal.  per  square  mile  per  24  hours 

Maximum 

Average 

Built-up  

Suburban  

25 
15 

750,000 
450,000 

375,000 
225,000 

418 


DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


Sewers  over  2  feet  in  diameter  were  designed  to  carry  the  maximum  rate  of  sew- 
age flow  when  running  three-quarters  full  (not  three-quarters  full  depth).  Sewers  2 
feet  in  diameter  and  less  were  designed  to  carry  the  maximum  rate  of  sewage  flow 
when  running  one-half  full  capacity. 

The  coefficient  of  roughness  in  Kutter's  formula  was  taken  at  N  =  0.013  for  pipe 
sewers  and  0.015  for  concrete  and  brick  sewers. 

The  minimum  velocities  provided  for  in  the  design  of  the  main  drainage  system 
are  calculated  as  for  circular  sewers  and  are  believed  to  be  approximately  correct  for 
ordinary  cross-sections.    If  Q  =  the  maximum  volume  of  discharge  per  second,  the 

minimum  velocity  was  1.9  feet  per  second  when  the  volume  of  discharge  was  —  Q  and 

the  depth  of  flow,  in  terms  of  the  diameter,  was  0.34.   The  minimum  velocity  was  2.25 

2  3 

when  flowing  at  the  rate  of  —  Q  or  —  Q. 

3  4 

Storm  Water 

It  is  not  customary  for  cities  to  build  works  to  treat  all  their  storm  water.  The 
volume  is  so  great,  even  when  moderate  falls  of  rain  occur,  that  the  works  required  to 
purify  all  the  storm  water  would  be  excessively  large  and  costly.  There  is,  moreover, 
a  general  belief  that  the  waste  water  from  the  roofs  of  houses  and  from  the  streets 
does  not  contain  enough  putrescible  material  to  add  materially  to  the  pollution. 

The  literature  relating  to  the  treatment  of  storm  water  shows  that  experts  gener- 
ally consider  that  storm  water  from  closely  built-up  cities  is  capable  of  producing  at 
least  as  much  offense  as  house  sewage.  There  is  reason  for  believing  that  the  first  flush 
of  storm  water  is  worse  than  even  the  relatively  concentrated  sewage  of  European 
cities,  and  that  it  is  therefore  desirable  to  treat  a  portion  of  the  storm  water. 

European  and  American  Seivage. — Much  of  the  recorded  information  and  opinion 
which  exist  with  respect  to  the  polluting  effects  of  storm  water  is  based  upon  European 
conditions,  where  the  quantity  of  sewage  at  times  of  dry  weather  may  amount  to  20  or 
30  gallons  per  capita  per  24  hours.  If  the  quantity  of  sewage  in  American  cities  is 
taken  at  120  to  180  gallons  per  capita,  it  is  evident  that  the  argument  for  treating 
storm  water  has  more  weight  in  America  than  it  has  abroad,  for  if  storm  water  is  as 
bad  as  domestic  sewage  when  the  latter  is  concentrated  to  the  extent  of  20  or  30  gallons 
per  capita  per  day,  it  must  be  about  six  times  as  bad  when  the  domestic  sewage  is  so 
dilute. 

The  aggregate  weight  of  solid  matter  carried  by  storm  water  is  very  great.  Analy- 
ses can  be  quoted  which  show  that  the  percentage  of  suspended  matter  is  several  times 


MAIN  DRAINAGE  419 

as  high  in  sewage  containing  storm  water  as  it  is  in  purely  house  sewage.  This  being 
so,  and  it  being  remembered  that  the  volume  of  sewage  is  greatly  increased  at  times  of 
storm,  it  follows  that  the  total  amount  of  suspended  matter  carried  by  a  given  volume 
of  storm  water  is  much  greater  than  the  analyses  indicate. 

Numerous  experts  have  expressed  the  opinion  that  careful  attention  should  be 
given  to  the  polluted  character  of  the  first  flush  of  storm  sewage.  In  the  opinion  of 
Samuel  Rideal,  whose  familiarity  with  the  chemical  and  biological  composition  of  sew- 
age and  whose  knowledge  of  current  practice  in  England  entitles  him  to  be  regarded  as 
an  authority,  "whatever  system  be  adopted,  the  raw  storm  water  of  populous  districts 
should  never  be  allowed  to  pass  in  large  volumes  at  the  beginning  of  a  storm  directly 
into  a  stream."  Dr.  Dunbar,  Director  of  the  Hygienic  Institute  at  Hamburg,  and  an 
authority  on  sewage  disposal  on  the  Continent  of  Europe,  as  well  as  in  England,  says : 
"It  must  not  be  supposed  that  the  contents  of  rain  water  sewers  are  in  general  not  so 
polluted  as  ordinary  sewage.  In  busy  districts,  the  washings  from  the  streets,  even  if 
these  are  thoroughly  cleaned  daily,  are  everywhere  found  to  be  worse  in  every  respect, 
including  putrescibility,  than  ordinary  sewage."  Dr.  Houston,  the  celebrated  English 
bacteriologist,  says  that  storm  water  is  as  "potentially  dangerous  to  health  as  normal 
crude  sewage."   To  these  opinions  many  more  could  be  added  to  the  same  effect. 

American  Analyses. — There  is  scant  information  on  record  to  show  the  composi- 
tion of  storm  water  in  American  cities,  although  some  data  are  available  to  indicate 
the  average  composition  of  sewage  containing  the  combined  drainage  of  houses  and 
streets.  This  information  is  not  as  valuable  as  it  would  be  if  it  had  been  collected  with 
the  intention  of  showing  the  difference  in  composition  which  occurs  in  the  sewage  of  a 
given  city  during  dry  weather  and  at  periods  of  storm,  but  some  facts  exist  with  respect 
to  this  subject. 

At  a  testing  station,  established  at  Gloversville,  N.  Y.,  at  which  analyses  were 
made  continuously  for  about  one  year,  1908-1909,  the  marked  effect  of  storm  water 
upon  the  dry-weather  flow  was  shown  in  the  following  manner.  Following  a  period 
of  dry  weather,  rain  fell  for  practically  24  hours  on  June  5th  and  the  flow  of  sewage 
increased  31  per  cent.,  although  comparatively  few  storm  water  drains  were  connected 
with  the  sewers.  The  storm  water  came  chiefly  from  the  roofs  of  houses  and  from  the 
streets.   The  strength  of  the  sewage  increased  as  follows  :* 

Total  suspended  solids  from  312  to  622  parts  per  million,  or  166  per  cent. 

Volatile  suspended  matter  from  196  to  254  parts  per  million,  or  73  per  cent. 

Fixed  suspended  solids  from  116  to  368  parts  per  million,  or  324  per  cent. 

*  Report  to  the  City  of  Gloversville,  N.  Y.,  by  Eddy  and  Vrooman,  Aug.  7,  1909,  p.  57. 


420         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

It  is  worth  noting  that  the  largest  increase  in  suspended  matter  was  due  to  non- 
volatile, fixed  or  mineral  matter.  This  suggests  that  storm  water  is  peculiarly  sus- 
ceptible of  improvement  by  settlement,  an  inference  which  is  not  strictly  correct,  for 
the  removal  of  mineral  matter  would  not  produce  nearly  as  much  benefit  as  the  removal 
or  organic  or  nitrogenous  matter.    A  large  part  of  the  suspended  matter  is  grit. 

The  average  composition  of  the  combined  sewage  of  some  American  cities,  as  deter- 
mined by  numerous  analyses  made  at  investigating  laboratories,  is  indicated  in  Table 
XCI. 


TABLE  XCI 

Composition  of  Sewage  at  Various  Testing  Stations. 

(Parts  per  Million) 


Suspended  Solids. 

Nitrogen  as 

Oxygen 
Consumed. 

CI. 

Fat. 

Total. 

Fixed. 

Vola- 
tile. 

Or- 
ganic. 

Free 
Am. 

Nitrite. 

Ni- 
trate. 

Total. 

Sus. 

Dis. 

1.  Boston,  1903-5  

18.5 
13.9 
11.0 

7.8 
12.0 

4.0 

.19 
.00 
.09 
.14 

.38 
.23 

.10 
.20 
.20 

1.52 
.87 

1.00 

43.1 
56.0 
51.0 
46.0 
95.0 
76.0 

19.3 
13.0 
25.0 
20.0 
50.0 

23.8 
43.0 
26.0 
26.0 
45.0 
40.4 

2.  Boston,  1905-7  

135 
209 
165 
406 
189 

44 
130 

50 
177 

59 

91 
79 
115 
229 
130 

9.1 
9.0 
14.8 
23.0 
6.3 

3.  Columbus,  1904-5  

4.  Waterbury,  1905-6  

5.  Gloversville,  1908-9  

6.  Philadelphia,  1909-10 

65 
48 
158 
39 

25 
26 
48 
28 

In  each  of  the  investigations  whose  results  are  indicated  in  the  foregoing  table,  an 
effort  was  made  to  obtain  results  which  would  be  helpful  in  the  design  of  works  for  the 
purification  of  the  sewage.  Certain  peculiarities  were  thought  to  exist  in  the  sewage  to 
be  dealt  with  which  it  was  necessary  to  determine  and  the  amenability  of  the  sewage  to 
purification  was  tested  in  each  case. 

It  will  be  observed  that  the  sewages  tested  at  the  experiment  stations  varied  con- 
siderably in  the  amount  and  nature  of  the  suspended  matter,  as  well  as  in  the  dis- 
solved impurities.  If  partial  treatment  only  had  been  thought  sufficient,  it  would  not 
have  been  necessary  to  make  the  analyses  so  complete.  So  far  as  the  general  character  of 
the  average  sewage  dealt  with  is  concerned,  the  figures  given  are  satisfactory,  but  they 
should  be  employed  with  caution  in  forming  an  opinion  as  to  the  composition  of  the 
sewage  of  other  cities  where  importance  attaches  to  questions  of  detail. 

Opinion  With  Respect  to  Manhattan  and  Brooklyn. — Should  the  house  and  storm 
sewage  of  Manhattan  be  collected  in  separate  systems,  it  would  be  desirable  certainly 
to  treat  all  of  the  one  and  perhaps  part  of  the  other.  This  could  not  conveniently  be 
done  in  the  same  plants.   Should  both  house  and  storm  sewage  be  collected  by  the  com- 


MAIN  DRAINAGE  421 

bined  system,  the  treatment  works  should  be  so  designed  as  to  deal  with  the  dry-weather 
flow  and  have  enough  more  capacity  to  take  care  of  the  heavily  polluted  water  which 
would  be  washed  from  the  streets  and  houses  with  the  first  flush  of  the  rain.  It  would 
be  well  to  have  the  capacity  of  the  main  sewers  and  disposal  works  equal  to  twice  the 
average  dry-weather  flow. 

SEWAGE  DISPOSAL 

The  method  of  final  disposition  which  it  is  best  to  employ  in  any  case  depends 
largely  upon  the  facilities  which  are  available  for  discharging  the  sewage  after  treat- 
ment into  the  natural  body  of  water  which  must  receive  it. 

If  the  volume  of  sewage  is  relatively  small  as  compared  with  the  quantity  of 
water  into  which  it  can  be  discharged  and  the  point  of  outfall  is  so  situated  as  to  be 
removed  from  localities  where  there  is  likely  to  be  offense,  a  minimum  degree  of  treat- 
ment is  all  that  is  required.  On  the  other  hand,  if  the  diluting  capacity  of  the  natural 
body  of  water  is  small  and  the  point  of  outfall  so  situated  that  the  discharge  of  the 
sewage  may  produce  a  nuisance,  a  more  thorough  removal  of  the  offensive  ingredients 
is  called  for.  Every  situation  requires  independent  study.  There  are  no  rules  which 
it  is  safe  to  lay  down  for  universal  application.  What  is  permissible  with  one  group  of 
conditions  may  prove  to  be  entirely  unsatisfactory  with  another. 

Considerable  misapprehension  exists  on  the  part  of  the  public  concerning  the  pos- 
sibilities of  sewage  purification,  it  being  believed  by  many  persons  that  the  manurial 
ingredients  constitute  a  rich  source  of  profit  and  by  many  others  that  it  is  within  the 
range  of  practicability  to  so  deal  with  sewage  in  disposal  plants  that  the  effluent 
shall  be  incapable  of  producing  nuisance  and  be  harmless  from  the  standpoint  of 
disease.  Theoretically,  such  thorough  purification  can  be  effected,  but  practically  it 
is  rarely,  if  ever,  accomplished.  Only  in  rare  instances  is  it  necessary  or  possible  to 
attempt  such  thorough  treatment.  The  cost  of  completely  ridding  sewage  of  its  nui- 
sance or  disease-producing  capacity  and  the  nuisance  which  is  likely  to  be  produced 
in  the  vicinity  of  such  works  make  it  desirable  to  seek  some  other  solution  of  the  sew- 
age problem.  It  may  be  better  to  collect  the  sewage  to  some  other  central  point  or 
discharge  the  effluent  into  some  other  natural  body  of  water  or  to  modify  the  standard 
of  purity  required  for  the  effluent. 

Among  the  methods  of  disposal  most  often  employed  is  the  discharge  of  the  crude 
sewage  into  a  river,  lake  or  harbor  under  circumstances  which  seem  likely  to  carry  it 
promptly  away.  This  has  been  termed  the  method  of  dilution,  but,  as  practiced  by 
most  cities,  disposal  in  this  manner  is  less  a  method  than  a  means  of  escaping  the 
methodical  disposition  of  the  sewage. 


422         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

In  disposal  through  dilution,  the  sewage  is  ordinarily  carried  by  a  local  or  main 
drainage  system  to  one  or  more  points  and  discharged  where  the  prevailing  currents 
will  carry  it  away.  Where  the  discharge  can  be  made  into  rivers,  especially  those 
whose  waters  are  muddy  and  of  ample  volume,  and  where  the  chances  of  nuisance  or 
injury  to  health  to  other  communities  further  down-stream  may  be  neglected,  this  way 
of  getting  rid  of  the  sewage  has  much  to  recommend  it.  It  is  the  cheapest  plan  that 
can  be  followed.  Where  the  diluting  power  of  the  natural  body  of  water  is  insuffi- 
cient, where  the  currents  oscillate,  as,  for  example,  in  tidal  harbors  or  where  water  sup- 
plies are  likely  to  be  injuriously  affected,  disposal  by  dilution  is  less  applicable. 

Engineers  who  have  studied  the  subject  have  arrived  at  the  opinion  that  so  far  as 
nuisance  is  concerned,  disposal  through  dilution  is  likely  to  prove  satisfactory  in  inland 
rivers  where  the  quantity  of  water  flowing  is  equal  to,  or  greater  than,  about  3y2  cubic 
feet  per  second  per  thousand  of  population  supplying  the  sewage.  See  this  report, 
Part  III,  Chapter  II,  Section  IV,  page  335,  and  Part  IV,  Chapter  VI,  page  633.  For 
reasons  which  are  explained  elsewhere,  it  is  impossible  to  calculate  the  dilution  which 
the  sewage  of  New  York  receives  when  discharged  into  New  York  harbor.  See  this 
report,  Part  IV,  Chapter  III,  page  493. 

Where  the  dilution  is  insufficient  to  dispose  of  crude  sewage  satisfactorily,  some 
form  of  treatment  which  will  remove  sufficient  of  the  impurities  to  permit  the  remain- 
der to  be  discharged  is  usually  resorted  to.  The  design  of  the  disposal  works  depends 
upon  the  degree  of  purification  required  and  the  opportunities  which  are  available, 
such  as  area  of  land,  hydraulic  head  at  which  the  sewage  may  be  obtained,  location  of 
the  works  with  respect  to  the  congestion  of  resident  or  business  population  in  the 
vicinity  and  the  facility  with  which  the  impurities  which  are  removed  can  be  disposed 
of.  The  best  design  of  works  will  take  into  consideration  all  of  these  factors  as  they 
relate  to  the  particular  situation  under  consideration  and  have  due  regard  to  the  need 
of  keeping  the  cost  of  construction  and  maintenance  down  to  the  lowest  terms. 

The  methods  which  are  available  for  the  purification  of  sewage  may  be  divided 
into  two  large  classes:  Those  which  contain  processes  for  the  mechanical  removal  of 
the  impurities  and  those  in  which  oxidizing  processes  are  employed. 

No  single  process  is  in  itself  complete.  Even  the  simplest  methods  of  sewage  dis- 
posal which  are  likely  to  be  employed  in  any  city  require  the  combination  of  two  or 
more  distinctly  different  steps. 


MAIN  DRAINAGE  423 

Mechanical  Processes 
1.    Fine  Screens 

Screens  designed  primarily  for  the  removal  of  the  small  particles  of  suspended 
matter  in  sewage  as  distinguished  from  rags,  sticks,  straw,  orange  skins,  etc.,  are  gen- 
erally known  as  "fine"  screens  and  have  free  spaces  between  the  bars  or  wires  of  15 
mm.  (0.6  inch)  or  less. 

They  may  be  classified  as  consisting  of  bars,  links,  a  wire  mesh  or  a  perforated 
plate;  as  fixed  or  movable;  according  to  the  general  design.  There  are,  in  particular, 
three  prominent  types  of  fine  screens,  all  of  them  of  German  origin,  viz. :  the  Ham- 
burg, the  Frankfort  and  the  Dresden  types. 

These  are  all  in  successful  and  satisfactory  operation  in  a  number  of  German 
cities.  They  are  usually  operated  by  electric  motors  and  are  cleaned  above  the  surface 
of  the  sewage. 

The  Hamburg  Screen.  The  Hamburg  screen  consists  of  a  band  composed  of 
aluminum  links  0.2  in.  thick,  14.4  in.  long  and  spaced  15  mm.  (0.6  in.)  apart.  There 
are  two  screens,  side  by  side,  at  the  lower  end  of  the  grit  chamber,  each  11%  ft.  wide. 
They  pass  in  an  inclined  position  over  two  rollers,  one  above  and  the  other  below  the 
sewage.    The  entire  length  from  out  to  out  is  32.8  ft. 

As  the  upper  links  rise  slowly  from  the  surface  they  carry  the  material  which  has 
collected  over  the  top  roller.  Behind  the  screen,  near  the  top,  there  is  a  rake  of  hard 
rubber  which,  by  mechanism,  engages  between  each  set  of  links,  scraping  off  the 
detritus,  which  is  then  scraped  from  the  rake  on  its  withdrawal  on  to  a  lateral  belt 
conveyor.    The  velocity  of  the  screen  is  about  0.2  or  0.24  in.  per  second. 

To  operate  the  screen  and  the  cleaning  device  about  5  H.  P.  is  required. 

The  Frankfort  Screen.  At  Frankfort- on-the-Main  there  are  three  screens  in  form 
like  paddle-wheels.  Each  is  composed  of  five  blades  or  wings  extending  9.8  feet  from 
the  axis  and  6.6  feet  wide.  The  wings  themselves  are  made  up  of  straight  parallel 
bars  placed  radially  to  the  axis  and  spaced  10  mm.  (0.4-in.)  apart.  In  operation  the 
lower  wings  move  against  the  current,  intercepting  the  detritus  which  is  unable  to 
pass  beyond,  as  one  wing  of  the  screen  always  occupies  the  cross-section  of  the  stream. 

As  the  wing  rises,  a  straight  scraper  of  rubber,  hung  at  each  end  by  a  long  arm 
from  above  the  center  of  the  screen,  is  forced  from  near  the  axle  to  the  outer  edge, 
carrying  with  it  the  screenings,  which  drop  on  a  horizontal  plate.  On  the  horizontal 
motion  of  this  plate  the  screenings  are  scraped  off  to  a  lateral  belt  conveyor  and 
transported  for  disposal.  After  reaching  the  edge  of  the  wing  the  scraper  drops  to 
the  inner  part  of  the  following  wing  and  the  operation  is  repeated. 


424         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

The  sewage  passes  a  coarse  screen  with  155  mm.  (6.1-in.)  spaces  between  the  round 
bars  and  then  a  grit  chamber  before  reaching  the  fine  screens.  Of  the  suspended  solids 
in  the  raw  sewage  16%  are  removed  by  the  grit  chamber  and  10%  more  by  the  screens 
(Koelle).    Other  analyses  made  several  years  ago  gave  the  following  average  results: 


Suspended  Matter 

Per  Cent. 

Parts  per  Million. 

Removal. 

Total. 

Organic. 

Total. 

Organic. 

411 

241 

325 

185 

20^9 

23  !2 

The  Dresden  Screen.  The  Dresden,  otherwise  known  as  the  Riensch-Wurl,  screen 
consists  of  a  circular  bronze  disc,  26.2  ft.  in  diameter,  on  the  center  of  which  is  placed 
a  conical  plate  of  less  diameter.  These  plates  are  perforated  with  slots  2x30  mm. 
(.08x1.20  in.)  in  size.  The  whole  is  mounted  on  a  central  shaft  inclined  15°  to  the 
vertical  around  which  it  revolves  once  in  about  three  minutes.  Being  partly  sub- 
merged in  a  channel  closely  fitting  the  lower  edge  of  the  disc,  the  suspended  material 
is  gently  raised  above  the  surface  and  on  reaching  the  highest  point  is  brushed  off  the 
disc  by  cylindrical  brushes  on  the  ends  of  four  revolving  arms.  The  conical  surface 
is  cleaned  by  a  single  large  cylindrical  brush.  The  screenings  fall  to  a  conveyor  by 
which  they  are  removed  from  the  vicinity  of  the  screen. 

The  sewage  first  passes  a  grit  chamber,  then  coarse  screens  with  bars  spaced  45 
and  66  mm.  (1.8  and  2.6  in.)  apart,  which  remove  about  V20  cu.  yd.  of  paper,  rags 
and  other  coarse  material  for  each  million  gallons  of  sewage. 

The  fine  screens  remove  15  to  20  cu.  yds.  additional,  containing  80%  moisture. 
The  following  table  gives  the  results  of  22  tests  made  between  Feb.  18  and  May  4,  1913 : 


Samples  taken: 


Before  Screening. 


After  Screening. 


Suspended  solids,  ppm*  

Specific  gravity  

Per  cent,  moisture. . . . 
Weight  of  dried  material — 

In  grams  per  litre  

Mineral     "  "   

Organic     "  "   


5590 
1.5537 
95.8 

0.30512 
0.11162 
0.18995 


3520 
1.5622 
95.1 

0.23672 
0.09280 
0.13673 


*  Parts  per  million. 

About  2y2  H.  P.  is  consumed  in  operating  one  of  these  screens. 


MAIN  DRAINAGE  425 

2.    Grit  Chambers 

All  sewage,  and  particularly  the  sewage  from  combined  systems  of  sewers,  con- 
tains grit  and  other  relatively  heavy  particles.  Attempts  are  often  made  to  remove  as 
much  of  this  heavy  matter  as  possible  before  the  sewage  passes  entirely  from  the  street 
gutters  to  the  sewers.  The  devices  customarily  employed  for  this  purpose  are  called 
catch-basins. 

Theoretically  desirable,  catch-basins  are,  in  reality,  among  the  most  useless  de- 
vices employed  for  the  removal  of  solid  material  from  sewage.  They  are  generally  inef- 
fective because  they  are  not  cleansed  with  sufficient  frequency  to  enable  them  to  serve 
as  traps.  It  seems  impracticable  to  keep  them  clean.  To  maintain  catch-basins  in  ser- 
viceable condition  requires  much  hand  labor,  and  this  is  costly.  The  work  is  usually 
carried  on  to  the  annoyance  of  pedestrians  and  householders.  Some  sewerage  systems 
are  without  catch-basins,  and  their  elimination,  as  a  general  procedure,  is  much  to  be 
desired. 

Where  sewage  from  a  combined  system  of  sewers  has  to  be  pumped,  it  is  custom- 
ary to  construct  at  the  pumps  coarse  screens  to  remove  large,  light  suspended  solids, 
and  grit  chambers  to  collect  sand  particles  and  such  heavy  suspended  matters  as 
are  capable  of  being  quickly  deposited  when  the  sewage  is  brought  to  a  state  of  com- 
parative rest.  Grit  chambers  are  capable  of  being  efficiently  operated,  for  their  size, 
location  and  form  make  them  comparatively  easy  to  clean.  Mechanical  dredging 
apparatus  may  be  located  above  the  grit  chambers  and  so  operated  as  to  remove  the 
accumulations  as  rapidly  as  they  are  deposited.  The  solids  extracted  are  of  little  or 
no  use.  They  are  commonly  removed  in  cars  which  run  upon  industrial  railways  and 
discharge  their  contents  into  barges  or  into  railroad  conveyances  for  ultimate  dump- 
ing. The  gritty  material  may  produce  offensive  odors  because  the  organic  matters 
which  cling  to  it  are  capable  of  putrefaction. 

Grit  chambers  are  of  much  practical  service  when  used  in  connection  with  coarse 
and  fine  screens.  The  sewage  first  flows  through  the  coarse  screens,  then  through  the 
grit  chambers  and  finally  through  the  fine  screens.  It  is  customary  to  build 
screens  and  grit  chambers  in  duplicate  so  as  to  facilitate  the  work  of  cleaning  and 
repairing. 

Grit  chambers  and  screens  take  up  but  little  room.  They  can  be  constructed  in 
the  built-up  parts  of  cities.  No  offensive  odor  need  be  produced  by  them.  They  are 
appropriately  employed  wherever  the  pumping  of  sewage  is  necessary,  wherever  much 


426         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

gritty  matter  is  washed  from  the  streets,  and  in  those  cases  where  the  sewage  is  subse- 
quently to  be  treated  for  the  more  complete  removal  of  its  impurities.  In  Germany, 
where  much  sewage  is  discharged  into  large,  rapidly  flowing,  turbid  rivers,  fine  screen- 
ing is  a  standard  procedure,  except  where  a  more  complete  removal  of  the  suspended 
matters  by  sedimentation  is  adopted.  Even  in  this  case  they  are  sometimes  placed 
before  the  tanks  to  take  out  the  floating  material. 

To  remove  the  greater  part  of  the  grit  with  the  least  amount  of  organic  matter 
the  velocity  of  flow  through  the  grit  chamber  should  not  vary  greatly  from  one  foot 
per  second. 

3.    Sedimentation  Basins 

Sedimentation  basins,  wherein  the  sewage  stands  almost  at  rest  for  a  period  gen- 
erally of  two  hours,  more  or  less,  generally  take  the  form  of  large,  shallow,  open 
masonry  reservoirs.  The  sewage  enters  at  one  end  and  flows  out  at  the  other,  the  de- 
sirable rate  of  passage  being  generally  not  over  an  inch  per  second.  Compartments, 
baffles,  wiers  and  other  devices  are  sometimes  employed  in  order  to  secure  a  uniform 
rate  of  flow.  If  left  to  itself  in  a  large  basin  the  sewage  will  flow  in  and  out  by  the 
shortest  route  and  will  not  circulate  with  that  completeness  necessary  to  afford  the 
longest  period  possible  for  deposition.  Special  pains  must  be  taken  to  compel  the  sew- 
age to  flow  uniformly  through  the  basin  in  order  that  all  the  solid  particles  shall 
have  an  equal  opportunity  to  settle  out. 

In  some  cases  sedimentation  basins  are  constructed  with  hopper-shaped  sumps  in 
the  bottom,  facility  in  cleaning  being  thus  obtained. 

The  ordinary  sedimentation  basin  is  cleaned  by  drawing  off  the  sewage  and  send- 
ing laborers  with  rubber  boots  and  squeegees  to  push  the  solid  accumulations  on  the 
bottom  to  the  outlet  pipes.  This  cleaning  is  expensive  and  unsatisfactory  from  a  sani- 
tary standpoint.  It  is  an  exceedingly  dirty  operation.  Tanks  built  with  hopper  bot- 
toms require  little  or  no  hand  labor  in  removing  the  sludge. 

A  type  of  settling  basin  which  has  recently  received  much  favorable  notice  has  a 
relatively  small  superficial  area  and  great  depth.  The  solid  matters  which  are  depos- 
ited can  be  drawn  off  from  the  bottom  without  emptying  the  tank  of  sewage.  Several 
forms  of  this  deep  tank  are  in  use.    The  oldest  is  known  as  the  Dortmund  tank. 

The  Dortmund  tank  resembles  a  cylinder  or  cube  with  a  conical  or  pyramidal  bot- 
tom. The  most  recent  forms  are  somewhat  complicated,  but  have  advantages  which 
appear  to  make  them  a  distinct  improvement  over  earlier  types  of  settling  basins. 


MAIN  DRAINAGE  427 

The  latest  advance  lies  in  providing  the  deep  settling  basins  with  traps  or  com- 
partments at  the  bottom,  into  which  the  depositing  solid  matters  settle  and  decom- 
pose. The  gases  of  decomposition  which  rise  from  the  deposits  in  the  lower  chamber 
escape  through  vents  especially  provided  for  them.  The  sewage  does  not  decompose  as 
it  passes  through  the  settling  basin,  nor  become  foul  smelling,  but  remains  almost  as 
fresh  and  inodorous  as  it  was  when  it  arrived  at  the  works.  The  deposited  matter 
which  ferments  gives  off  large  volumes  of  gas  which  are  inoffensive.  This  settling 
basin,  known  as  the  Emscher  tank,  from  the  name  of  a  small  river  valley  in  Germany, 
where  it  was  first  employed,  is  now  being  installed  in  many  cities  in  Europe  and 
America. 

The  period  of  settlement  allowed  for  the  deposit  of  the  solid  matters  from  the 
sewage  is  commonly  four  hours  or  more,  but  occasionaly  it  is  less  than  two  hours. 
The  material  which  is  deposited  from  the  sewage  and  allowed  to  ferment  in  the  sepa- 
rate chamber  of  the  Emscher  tank  is  reduced  in  volume  by  decomposition  and  so  al- 
tered in  physical  constitution  that  it  easily  parts  with  its  water  when  spread  out  upon 
a  coarse  draining  bed. 

When  ordinary  sewage  is  allowed  to  remain  in  a  quiescent  condition  for  eight 
hours  or  more,  it  undergoes  a  process  of  biological  change  which  is  essentially  putre- 
faction. The  oxygen  which  was  present  in  dissolved  form  is  consumed  and  anaerobic 
fermentation  sets  in.  Sedimentation  basins  in  which  anaerobic  action  takes  place 
throughout  the  volume  of  sewage  are  known  as  septic  tanks.  They  are  usually  offen- 
sive by  reason  of  the  unpleasant  odors  which  they  give  off.  In  order  to  reduce  the 
nuisance  from  smell  and  to  facilitate  the  biological  actions  which  are  desired,  the 
tanks  are  sometimes  covered. 

At  one  time  it  was  supposed  that  the  putrefactive  fermentation  of  sewage  was 
highly  desirable  from  the  standpoint  of  purification.  It  was  believed  that  the  solid 
organic  matters  which  the  sewage  contained  could  be  completely  converted  into  liquid 
and  gaseous  forms  by  the  so-called  septic  action  and  that  the  greatest  obstacle  to  the 
purification  of  sewage,  namely,  the  disposition  of  the  sludge,  would  in  this  way  be  done 
away  with.  Experience  has  failed  to  justify  this  expectation.  Septic  tanks  are  now 
regarded  with  less  favor  than  formerly.  It  is  not  held  to  be  desirable  to  putrefy  sew- 
age as  a  step  toward  complete  purification.  It  seems  better  to  keep  it  as  fresh  as  prac- 
ticable throughout  the  purifying  process. 

Septic  tanks  have  usually  been  built  in  the  form  of  large  and  comparatively  shal- 
low basins.  They  should  not  be  located  in  a  closely  built-up  city.  The  sewage  which 
passes  from  them  is  often  highly  offensive.    If  the  sewage  is  to  be  subjected  to  final 


428  DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

treatment  on  sprinkling  filters,  the  odors  in  the  vicinity  of  the  filters  are  likely  to 
cause  complaint.  There  are  some  situations  in  which  septic  tanks  may  be  useful,  as, 
for  example,  in  small  installations  where  the  quantity  of  sludge  must  be  reduced  to  a 
minimum  and  where  odors  are  not  seriously  objectionable. 

Sludge. — The  disposition  of  the  solid  impurities  which  are  removed  from  sewage 
in  sedimentation  basins  constitutes  the  most  serious  problem  usually  confronting  sew- 
age engineers.  This  material,  termed  sludge,  unless  it  is  retained  a  long  time  in  the 
basin  so  as  to  decompose,  consists  largely  of  colloidal  matter.  Its  specific  gravity  is 
but  slightly  greater  than  that  of  the  sewage  from  which  it  has  been  deposited.  It  con- 
sists largely  of  water,  and  this  water  can  be  extracted  only  with  the  greatest  difficulty. 
Sludge  will  remain  for  months  without  perceptible  change  in  physical,  chemical  or 
biological  condition.  It  flows  like  water,  a  fact  which  has  led  engineers  to  say  that 
pumping  was  the  only  thing  which  it  was  easy  to  do  with  sludge. 

Sludge  can  be  dried,  although  drying  is  usually  a  difficult  and  expensive  process. 
The  water  can  be  extracted  by  filter  presses.  It  can  be  removed  in  centrifugal  machines. 
When  dried,  sludge  can  be  burned. 

The  usual  way  of  dealing  with  sludge  is  to  dtimp  it  upon  low-lying  land.  Cities 
situated  upon  the  sea  sometimes  pump  it  into  ships  which  carry  it  to  the  ocean  and 
there  discharge  it  overboard.  Some  cities  bury  it,  others  dig  it  into  the  soil,  a  few 
dry  and  burn  it,  and  perhaps  a  dozen  turn  it  into  fertilizer. 

If  sludge  is  so  managed  as  to  permit  it  to  ferment,  it  undergoes  changes  which 
alter  its  physical  condition.  In  place  of  the  amorphous,  almost  slimy  consistency 
which  it  originally  possessed,  it  becomes  somewhat  granular  and  porous.  Placed  upon 
a  suitable  under-drained  piece  of  land,  fermented  sludge  quickly  drains  itself  of  a 
large  part  of  its  water,  so  that  in  a  few  days  it  may  be  spaded.  It  is,  moreover,  with- 
out unpleasant  odor.  It  is  obvious  that  in  fermentation  there  lies  a  good  prospect 
of  dealing  with  sewage  sludge  in  an  economical,  sanitary  and  otherwise  effective  man- 
ner. The  deep  settling  tanks  employed  in  the  Emscher  district  produce  a  sludge  of  this 
character. 

It  is  not  necessary  to  employ  any  special  type  of  settling  basin  in  order  to  fer- 
ment sludge.  It  may  be  fermented  as  readily  a  mile  or  more  away  as  in  the  basin  in 
which  it  was  produced  from  the  sewage.  For  fermentation  to  proceed  satisfactorily 
it  is  necessary  only  that  the  sludge  shall  be  kept  in  a  tank  or  compartment  separate 
from  the  sewage.  Fermentation  will  not  proceed  satisfactorily  in  a  tank  which  is  im- 
mediately filled  with  sludge  to  a  depth  of  6  feet,  but  a  tank  which  is  filled  very  grad- 
ually will  permit  fermentation  to  proceed  in  a  satisfactory  manner. 


MAIN  DRAINAGE  429 

Settling  basins  are,  for  the  most  part,  devices  which  should  be  employed  at  points 
removed  from  built-up  residential  or  commercial  districts.  The  older  types  of  tanks 
are  so  large  as  to  require  more  space  than  can  ordinarily  be  afforded  where  the  value 
of  property  is  high  and  a  considerable  amount  of  odor  arises  from  tbem  during  the 
process  of  cleaning. 

The  newer  type  of  tanks,  which  require  but  little  space,  which  are  nearly  inodor- 
ous in  operation  and  not  emptied  during  cleaning,  may  more  suitably  be  constructed 
near  built-up  parts  of  cities.  The  size  of  the  installation,  or,  in  other  words,  the  quan- 
tity of  sewage  to  be  dealt  with  must  be  considered  in  this  connection.  A  small  plant 
might  not  be  objectionable  where  a  large  one  would  cause  complaint.  The  great  depth 
of  the  newer  tank  and  its  somewhat  complicated  shape  make  it  more  expensive  to 
construct  than  the  older  form  of  basin. 

There  are  situations,  as,  for  example,  where  sufficient  land  is  not  to  be  had,  where 
the  deep  form  may  be  more  desirable  than  the  shallow  form.  The  advantage  which 
attaches  to  the  fermentation  of  the  sludge,  accomplishing,  as  it  does,  a  substantial 
reduction  in  the  bulk  and  facilitating  an  easy  removal  of  the  contained  water,  makes 
this  type  of  sedimentation  basin  of  peculiar  value. 

4.    Chemical  Precipitation 

To  facilitate  the  deposition  of  finely  divided  particles  of  suspended  matters,  re- 
course is  sometimes  had  to  chemicals.  The  chemicals  which  are  most  commonly  em- 
ployed are  lime,  alum  and  salts  of  iron.  They  are  added  in  solution  and,  immediately 
forming  floculi,  unite  the  minute  particles  of  suspended  matter  of  the  sewage  into  rela- 
tively large  masses,  which  sink  with  comparative  rapidity  through  the  sewage.  The 
principle  is  somewhat  like  that  employed  when  white  of  egg  is  used  to  clear  coffee.  If 
the  sewage  is  acid  in  character  lime  is  usually  employed  and,  if  lacking  in  iron,  this 
may  be  added  in  the  form  of  a  sulphate  to  add  weight  to  the  coagulated  particles,  caus- 
ing them  to  settle  more  rapidly. 

If  the  sewage  is  strongly  alkaline  it  may  be  treated  with  the  iron  sulphate  only; 
otherwise  alum  or  basic  sulphate  of  alumina  is  usually  added  in  sufficient  quantity  to 
combine  with  the  necessary  amount  of  iron.  If  the  sewage  is  alkaline  but  already 
containing  enough  iron,  then  alum  may  be  substituted.  Sometimes  both  alum  and  iron 
are  added.  The  particular  chemical  used  depends  largely  on  its  local  market  price. 
The  amount  used  varies  with  the  character  of  the  sewage ;  7  grains  of  ferrous  sulphate 
per  gallon  of  domestic  sewage,  from  2  to  10  grains  of  alum  and  twice  that  quantity  of 
lime  are  not  uncommon  in  practice. 


430  DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

It  is  claimed  that  the  use  of  chemicals  not  only  brings  about  a  more  rapid  set- 
tlement, but  causes  more  suspended  matter  to  subside.  There  is  also  a  slight  reduc- 
tion produced  in  the  dissolved  organic  matter.  In  exceptional  cases,  where  the  effluent 
is  discharged  to  a  large  stream,  the  use  of  chemicals  may  be  suspended  during  certain 
parts  of  the  year. 

Chemical  precipitation  is  carried  on  in  basins  of  the  same  form  and  size  as  are 
commonly  used  for  the  treatment  of  sewage  by  simple  subsidence.  Chemical  sludge  is 
much  greater  in  volume  per  unit  volume  of  sewage  than  is  sludge  produced  without 
chemicals,  but  the  physical  constitution  of  chemical  sludge  appears  to  be  not  materially 
different  from  that  of  ordinary  sludge.    It  is  neither  more  or  less  difficult  to  dry. 

Objection  to  the  chemical  precipitation  of  sewage  lies  in  the  cost  of  the  necessary 
chemicals  used  and  the  more  elaborate  plant.  To  dispose  of  the  large  volumes  of 
liquid  sludge  it  is  sometimes  pressed  into  the  form  of  thin  cakes.  For  satisfactory 
pressing  it  is  necessary  to  add  from  4  to  10  pounds  of  lime  to  each  cubic  yard  of  wet 
sludge.  The  ordinary  means  of  delivering  the  chemicals,  weighing  them,  dissolving 
them  and  applying  them  to  the  sewage  add  considerably  to  the  cost  of  operating  the 
sewage  disposal  plant.  In  most  cases  unpleasant  odors  are  produced  through  the  use 
of  the  chemicals,  although  the  chemicals  themselves  may  be  odorless. 

5.    Other  Processes 

Among  the  less  prominent  mechanical  methods  of  sewage  treatment  may  be  men- 
tioned the  hydrolytic  tanks  of  Dr.  Travis  and  the  slate  beds  of  Dibdin. 

The  hydrolytic  tank  resembles  the  Emscher  tank,  of  which  it  was  the  precursor,  in 
having  a  bottom  sludge  compartment.  Following  the  tank  the  sewage  passes  through 
a  tank  containing  a  large  number  of  sloping  slats  called  "colloiders,"  on  which  the 
very  fine  suspended  and  colloidal  matter  becomes  attached,  increasing  in  thickness 
until  it  falls  to  the  bottom  as  sludge.  It  is  claimed  that  the  removal  of  this  finer  mat- 
ter without  the  aid  of  chemicals  constitutes  an  important  advance  in  the  art  of  clarify- 
ing sewage. 

Dibdin's  slate  beds  consist  of  tanks  similar  to  those  used  for  sedimentation  but 
filled  with  slabs  of  slate  separated  by  small  blocks  about  2  inches  thick.  The  beds  are 
filled  and  drained  much  as  are  contact  beds.  In  this  way  the  sludge  accumulates  on 
the  surface  of  the  slabs  and  remains  there  until  decomposed.  The  process  being  car- 
ried on  in  the  presence  of  oxygen  is  free  from  the  odors  connected  with  decomposition 
in  septic  tanks  and  the  effluent  is  of  similar  character  to  that  from  ordinary  settling 
basins  having  an  equal  period  of  retention.  The  beds  are  flushed  out  at  long  intervals 
without  apparent  difficulty.    According  to  experiments  at  Philadelphia,  the  sludge 


MAIN  DRAINAGE  431 

removed,  which  is  gritty  rather  than  slimy  in  its  nature,  is  much  less  than  hy  other  pro- 
cesses of  sendimentation  except  Emscher  tanks,  but  the  area  required  is  relatively  great. 

The  efficiency  of  the  various  mechanical  processes  for  the  removal  of  the  suspended 
matters  is  shown  in  the  following  table : 


Removal  of 

Suspended  Matter 
Per  Cent. 

Organic  Matter 
Per  Cent. 

Coarse  Screening  

2—10 

1—6 

15—35 

10—25 

5—10 

1—3 

60  + 

30 

Chemical  Precipitation  

85 

50 

Biological  Processes 

The  biological  processes  which  are  employed  in  the  treatment  of  sewage  are, 
with  the  exception  of  septic  tank  and  Emscher  tank  treatment,  all  designed  to  take 
place  in  the  presence  of  oxygen.  In  fact,  omitting  disinfection,  ultimate  purification 
means  oxidation,  as  has  been  explained  in  the  Commission's  report  of  April,  1910,  Part 
III,  Chapter  X,  page  447. 

The  oxidizing  processes  are  roughly  divisible  into  two  main  groups :  the  first  con- 
tains those  which  require  large  areas  of  land,  as  irrigation  and  intermittent  filtration, 
and  the  second  those  in  which  relatively  small  areas  of  land  are  required.  The  methods 
contained  in  the  first  group  may  be  termed  extensive  and  those  contained  in  the  second 
intensive  processes.  Included  in  the  former  are  broad  irrigation  and  intermittent 
filtration  and  in  the  latter  contact  beds  and  percolating  filters. 

1.    Broad  Irrigation 

It  was  once  supposed  that  the  manurial  ingredients  of  sewage  could  be  extracted, 
or  at  least  employed  in  agricultural  processes,  in  a  profitable  way,  but  experience  indi- 
cates that  expectations  of  this  kind  are  usually  unfounded.  In  Europe  and  America  it 
has  been  found  that  sewage  cannot  be  applied  to  the  cultivation  of  crops  in  a  profit- 
able way  except  where  the  water  is  needed  for  irrigating  purposes.  Sewage  farms 
can  be  carried  on  to  advantage,  so  far  as  the  disposal  of  the  sewage  is  concerned, 
where  the  soil  is  suitable,  but  there  are  many  soils  which  are  practically  incapable  of 
absorbing  it.  The  areas  required  are  large,  and  a  large  margin  must  be  allowed  for  dis- 
posal purposes  during  rainy  weather.  Experience  has  shown  that  an  acre  of  land  is 
required  for  every  3,000  to  30,000  gallons  of  sewage  per  day  or  for  every  25  to  500  of 
contributing  population,  depending  on  the  climate,  soil,  preparation  of  ground,  etc. ; 
7,000  gallons  or  100  persons  per  acre  may  be  taken  as  an  ordinary  rate. 


432         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


Application  to  farm  land  is  not  practicable  for  New  York  because  of  the  great 
areas  of  land  required  and  the  completeness  with  which  the  country  within  fifty  miles 
of  the  city  is  occupied. 

2.    Intermittent  Filtration 

The  filtration  of  sewage  through  specially  prepared  beds  of  sand  is  an  excellent 
way  of  dealing  with  sewage,  provided  a  high  degree  of  purification  is  desired  and  the 
cost  of  the  land  and  its  preparation  are  not  prohibitive.  The  application  of  sewage 
either  to  farm  land  or  filters  usually  results  in  the  production  of  an  exceedingly  good 
effluent. 

Sewage  may  be  filtered  by  any  of  several  practical  methods.  A  field  may  be  suitably 
prepared  by  levelling,  under-draining  and  enclosing  within  embankments  the  area  of 
each  unit  serving  an  acre  or  more.  After  thoroughly  flooding  the  field,  the  inlet  is  shut 
off  and  an  opportunity  is  given  to  the  sewage  to  flow  downward  and  away  through  the 
underdrains.  The  field  is  then  rested  for  some  hours,  after  which  another  dose  of  sew- 
age is  applied  to  it. 

The  resting  of  sewage  fields  is  an  important  condition  to  provide  for.  It  permits 
bacterial  changes  to  proceed  under  circumstances  which  are  necessary  to  them  and 
prevents  the  clogging  of  the  pores  of  the  filtering  material.  Rest  is  also  useful  as  a 
means  of  bringing  the  sewage  into  contact  with  the  oxygen  of  the  atmosphere.  When 
the  sewage  filters  downward  in  an  intermittent  way  it  draws  atmospheric  air  with  it 
into  the  voids  between  the  particles  of  the  filtering  material,  and  the  oxygen  is  in  this 
manner  introduced  into  the  bed.  Purification  takes  place  chiefly,  but  not  exclusively, 
at  and  near  the  surface  of  the  ground. 

By  this  intermittent  application  to  specially  prepared  beds  much  larger  doses  of 
sewage  per  acre  may  be  employed  than  in  broad  irrigation.  Rates  of  50,000  to  100,000 
gallons  daily,  or  the  sewage  of  1,000  persons  per  acre,  are  not  unusual  with  this  method 
of  disposal. 

3.    Contact  Beds 

The  intensive  purification  of  sewage  is  at  the  present  time  considered  more  eco- 
nomical than  is  purification  on  extensive  acres  of  land. 

The  earliest  intensive  oxidizing  process  employed  masses  of  coarse  gravel  or  broken 
stone  in  what  were  termed  contact  beds.  These  beds  were  constructed  by  building  wa- 
ter-tight reservoirs  and  filling  them  to  a  depth  of  from  3  to  5  feet  with  stone  or  gravel, 
ranging  in  size  from  half  an  inch  to  three  inches  or  more  in  diameter.  The  size  should 
preferably  be  uniform.  In  a  few  cases,  broken  brick  and  coal;  in  others  tiles,  and  in 
some  cinders  are  used. 

Contact  beds  are  operated  by  filling  the  mass  of  broken  stone  from  the  bottom, 
allowing  the  sewage  to  remain  there  for  a  period  of  a  few  hours  and  then  drawing  it 


MAIN  DRAINAGE 


433 


away  from  the  filtering  material.  It  must  be  borne  in  mind  that  this  process  is  not 
one  of  filtration,  but  of  oxidation.  It  is  believed  that  the  solid  particles  of  which  the 
bed  is  composed  are  covered  with  bacteria  and  that  these  minute  organisms  are  instru- 
mental in  combining  the  oxygen  which  is  present  with  the  organic  matters  of  the 
sewage. 

As  to  the  rates  at  which  sewage  may  be  applied  to  contact  beds,  600,000  to 
1.000,000  gallons  per  acre,  daily,  are  common. 

Where  more  thorough  purification  is  demanded  the  sewage  is  put  through  two  or 
even  three  sets  of  beds.  With  double  contact  treatment  the  area  required  is  neces- 
sarily greater,  and  in  round  numbers  may  be  taken  as  one  acre  to  every  400,000  or 
500,000  gallons  per  day.  Single  contact  beds  reserved  for  storm  water  may  operate 
for  limited  periods  at  much  higher  rates,  perhaps  3,000,000  gallons  per  acre  daily. 

When  properly  built  and  operated,  contact  beds  are  capable  of  making  sewage 
non-putrescible.  In  other  words,  sewage  which,  if  allowed  to  stand  alone  or  mixed 
with  river  or  harbor  water  would  putrefy  and  give  off  offensive  odors,  can  by  their 
means  be  made  practically  incapable  of  further  decomposition.  The  contact  bed  is,  in 
reality,  a  means  of  hastening  the  process  of  decay  under  circumstances  which  are 
more  or  less  within  control. 

Contact  beds  produce  but  little  odor.  It  may  be  urged  against  them  that  they 
are  comparatively  expensive  and  they  require  comparatively  large  areas  of  land.  They 
should  be  situated  at  a  distance  from  built-up  residence  or  business  districts. 

Contact  beds  are  self-cleansing  when  well  built  and  managed.  After  long  intervals 
of  time  it  is  sometimes  necessary  to  replace  the  material  of  which  they  are  made,  but 
this  contingency  may  be  indefinitely  postponed,  if  not  completely  eliminated,  by  sci- 
entific design  and  operation. 

4.    Percolating  Beds 

The  most  approved  method  of  oxidizing  sewage  at  the  present  time  is  by  means 
of  percolating  beds,  sometimes  called  sprinkling  or  percolating  filters.  Oxidizing  beds 
of  this  kind  are  not  filters  in  any  sense  of  the  term.  There  is  usually  more  suspended 
matter  present  after  the  sewage  has  passed  through  them  than  before. 

A  sprinkling  filter  may  be  briefly  described  as  a  bed  of  broken  stone  or  gravel  from 
1  to  3  inches  in  size.  Beds  of  this  kind  need  no  water-tight  support  at  the  sides,  as 
do  contact  beds.  They  are  usually  from  5  to  9  feet  in  depth  and  should  be  well  under- 
drained  and  provided  with  a  carefully  arranged  apparatus  to  distribute  the  sewage 
evenly  over  the  stones,  for  it  is  desirable  that  all  parts  of  the  beds  should  receive  an 
equal  dosage. 

The  sewage  may  be  distributed  on  the  bed  by  sprinkling  from  fixed  nozzles  prop- 


434         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

erly  spaced,  from  small  holes  in  radial  pipes  swinging  about  a  center  or  from  troughs 
or  wheels  with  buckets  which  travel  back  and  forth  on  rectangular  beds.  In  the  mov- 
able sprinklers  the  motion  may  be  derived  from  the  reaction  or  weight  of  the  sewage,  or 
it  may  be  imparted  from  a  motor.  Fixed  nozzles  are  more  distinctive  of  American 
practice  and  rotary,  or  traveling  distributors,  of  European  practice.  In  either  case 
sprinkling  on  any  one  part  of  the  surface  should  not  be  continuous,  and  the  hourly 
rates  of  application  to  different  parts  of  the  surface  should  be  uniform. 

The  sewage  which  is  sprinkled  over  the  bed  percolates  slowly  downward  until  it 
reaches  the  under-drains,  when  it  is  carried  away.  Oxidation  takes  place  upon  the 
surface  of  the  stones. 

The  process  of  oxidation  which  takes  place  in  the  sprinkling  filter  is  apparently 
the  same  as  that  which  occurs  in  contact  beds.  There  is  this  difference,  however,  that 
the  particles  of  gravel  or  stone  are  never  submerged  in  the  percolating  bed,  but  are 
kept  continually  wet.  Filtration  may  be  continuous  or  intermittent,  the  intervals  be- 
tween doses  being  a  few  minutes.  The  oxygen  is  derived  from  the  atmosphere,  there 
being  in  well-constructed  percolating  filters  a  circulation  of  air  through  all  parts  of 
the  bed. 

Sprinkling  filters  are  more  efficient  than  contact  beds  in  that  a  larger  quantity 
of  sewage  can  be  purified  upon  a  given  area  of  land.  This  may  be  taken  at  from  l1/^ 
to  2  million  gallons  per  acre  daily,  depending  on  the  quality  of  the  sewage,  the 
depth  of  the  filter  and  the  size  of  the  material  of  which  it  is  made. 

Among  the  disadvantages  which  attach  to  sprinkling  filters  is  odor.  Owing  to  the 
sprinkling  of  sewage  into  the  atmosphere,  the  odor  is  especially  objectionable  in  those 
cases  where  the  sewage  is  in  an  advanced  stage  of  putrefaction  when  it  is  applied  on  the 
bed.  Another  disadvantage  is  in  the  fact  that  great  numbers  of  small  annoying  flies 
commonly  infest  the  works,  hatching  out  within  the  filter  beds.  It  is  not  known  that 
the  flies  are  ever  concerned  in  producing  sickness,  but  they  are  often  so  annoying 
as  to  cause  serious  complaint. 

Neither  the  mechanical  nor  oxidizing  treatment  of  sewage  is  capable  of  removing 
all  the  bacteria. 

5.    Other  Processes 

Attempt  was  made  by  the  late  Colonel  Waring  and  has  been  made  by  others  to 
make  use  of  atmospheric  oxygen  by  the  direct  application  of  air  in  the  purification  of 
sewage.  Although  beneficial  results  have  been  obtained  in  this  way,  they  have  generally 
not  been  commensurate  with  the  expense  involved.  Recent  experiments  by  the  Massa- 
chusetts State  Board  of  Health  in  this  line  have  been  favorably  reported  in  which  air  is 


MAIN  DRAINAGE  435 

discharged  into  the  bottom  of  a  tank  5  feet  deep  containing  vertical  layers  of  slate. 
Twenty-five  thousand  cubic  feet  of  air  per  hour  injected  for  five  hours  at  a  total  cost 
of  less  than  $2.00  are  said  to  not  only  render  the  sewage  quite  clear  and  inoffensive, 
but  to  produce  a  sludge,  digested  under  inoffensive  conditions,  that  is  free  from  objec- 
tionable odor,  granular  and  readily  removed.  The  real  processes  of  purification  are 
apparently  carried  on  in  the  films  of  deposit  that  form  on  the  surfaces  of  slate  and,  as 
they  become  decomposed,  slough  off. 

In  short,  the  direct  application  of  atmospheric  oxygen  to  sewage,  while  it  may  aid 
in  removing  odors  and  promote  conditions  favorable  to  purification,  does  not  appear  to 
have  any  substantial  immediate  effect.  Final  purification  is  effected  only  through  the 
agency  of  living  organisms,  and  this  takes  hours,  or  even  days,  to  accomplish. 

Nascent  oxygen  or  ozone  may,  however,  act  on  organic  impurities  much  more 
promptly.  The  action  is  in  the  nature  of  sterilization.  Various  processes  have  been 
devised  to  treat  sewage  in  this  way,  but  the  cost  has  usually  been  excessive. 

Disinfection 

In  order  that  sewage  may  be  rendered  harmless  to  health,  it  is  sometimes  disin- 
fected. Disinfection  can  be  accomplished  by  applying  bleaching  powder.  The  process 
can  be  carried  on  on  any  scale.  It  has  been  claimed  that  sewage  does  not  need  any 
preparation  for  the  disinfecting  treatment,  but  experience  shows  that  the  removal  of  at 
least  the  larger  suspended  particles  is  a  desirable  procedure  before  the  disinfectant  is 
used. 

The  amount  of  bleaching  powder  or  hypochlorite  required  depends  upon  the 
strength  of  the  sewage  and  on  the  proportion  of  impurities  to  the  "available  chlorine" 
in  the  commercial  chemical  used.  The  available  chlorine  should  amount  to  about  a 
third  of  the  commercial  salt.  The  amount  of  bleach  required  per  million  gallons  of 
fresh  sewage  may  generally  be  taken  at  from  100  to  250  pounds ;  for  septic  sewage  250 
to  400  pounds,  and  for  sprinkling  filter  effluents  from  75  to  100  pounds.  The  total  cost 
of  the  process  ranges  from  75  cents  to  $1.00  per  million  gallons. 

The  use  of  liquid  chlorine  in  place  of  bleach  is  a  recent  improvement  in  permitting 
greater  precision  in  the  measurement  of  the  dose,  a  more  complete  use  of  the  chlorine 
and  freedom  from  solid  residue. 

Sewage  may  be  disinfected  by  the  passage  of  an  electric  current  through  the  liquid. 
This  method  has  been  applied  with  more  or  less  success  in  a  few  small  towns,  but  the 
cost  per  million  gallons  (about  $9.00)  has  been  too  great  for  its  general  adoption. 


436 


DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


Sludge  Disposal 

The  disposal  of  the  sludge  removed  from  the  sewage  by  the  foregoing  methods  of 
treatment  is  often  a  difficult  problem.  In  volume  it  ranges  from  1  or  2  cubic  yards  per 
million  gallons  of  sewage  (70  per  cent,  water)  in  the  case  of  Emscher  tanks  to  20  or 
30  cubic  yards  with  chemical  precipitation  containing  perhaps  96  per  cent,  of  water. 
Unless  dumped  at  sea  or  run  onto  farm  lands  direct  as  a  fertilizer,  which  is  rarely 
done,  the  first  problem  is  the  reduction  of  the  moisture  so  as  to  reduce  the  bulk,  enable 
it  to  be  handled  conveniently  and  reduce  the  amount  of  odor  produced. 

This  may  be  accomplished  by  drying  in  the  air,  by  artificial  heat,  by  filter  pressing 
or  by  centrifugal  machines.  The  first  of  these  require  considerable  land,  with  the 
probability  of  nuisance,  and  the  others  require  expensive  machinery. 

If  spread  upon  the  land  from  0.1  to  0.2  acre  are  usually  required  for  every  100 
cubic  yards  of  sludge  produced  in  a  year. 

The  cost  of  filter  pressing  is  from  10  to  25  cents  per  ton  of  wet  sludge  or  $1.00 
per  ton  of  pressed  cake;  the  cost  of  centrifugalizing  about  10  cents  per  cubic  yard  of 
wet  sludge  or  45  cents  per  cubic  yard  of  product,  and  the  cost  of  further  drying  in  a 
rotary  drier  about  75  cents  per  ton  of  dried  material. 

Under  favorable  conditions  dried  sludge  may  have  a  certain  market  value  as  fer- 
tilizer. The  value  of  air-dried  sludge  for  this  purpose  is  nominal  only,  but  when  spe- 
cially prepared  after  drying  in  a  rotary  drier  it  may  find  an  occasional  market  at  $5.00 
or  $6.00  per  ton.  The  revenue  from  this  source  added  to  that  from  the  sale  of  grease 
that  may  be  recovered  in  some  instances  may  offset  the  cost  of  sludge  disposal  or  pos- 
sibly net  a  small  profit. 

EXAMPLES  OF  MAIN  DRAINAGE  OF  VARIOUS  LARGE  CITIES 

Baltimore 

Baltimore,  Md.,  with  a  population  of  558,483  according  to  the  census  of  1910, 
covers  an  area  of  32  square  miles.  Its  surface  is  hilly,  affording  rapid  velocities  in 
gutters  and  sewers.  The  city  is  divided  by  Jones  Falls,  a  stream  that  runs  in  a  south- 
erly direction  to  the  harbor.  The  harbor  is  an  arm  of  the  Patapsco  river,  projecting 
into  the  heart  of  the  business  center  of  the  city  from  Chesapeake  bay,  12  miles  away. 
The  harbor  is  without  appreciable  current  and  has  a  tidal  range  averaging  about  16 
inches.  The  condition  of  the  harbor  water  has  been  the  subject  of  complaint  for  many 
years. 

Parallel  to  the  Patapsco  and  a  short  distance  north  of  it  is  Back  river,  an  estu- 
ary of  considerable  width  for  several  miles  above  its  mouth.  Baltimore  was  without 
a  comprehensive  system  of  sewerage  until  plans  were  made  for  the  construction  of  a 
separate  system  and  disposal  works  after  the  fire  which  destroyed  a  large  part  of  the 


MAIN  DRAINAGE 


437 


city  in  1904.  Several  million  dollars  had  been  spent  on  storm  water  outlet  drains,  many 
of  them  of  large  size,  and  special  permits  had  been  granted  allowing  the  property  own- 
ers to  discharge  domestic  sewage  into  them.  In  the  newer  sections  of  the  city,  con- 
tractors had  provided  private  sewers  for  blocks  of  houses  which  they  built  and  obtained 
permits  to  discharge  the  drainage  into  the  natural  water  courses.  The  usual  practice 
was  to  discharge  house  sewage  into  large  cesspools  with  open  or  permeable  bottoms. 
These  were  cleaned  when  necessary,  the  volume  removed  in  1909  averaging  169  wagon 
loads  per  day.    The  cesspools  were  cleaned  by  contractors  with  so-called  odorless 


FIG.  4— BALTIMORE 

The  household  sewage  collected  on  the  separate  system  is  passed  through  settling  tanks,  sprinkling  filters  and 
subsequent  settling  tanks  before  discharge  into  the  Back  river. 


excavators,  loads  of  about  200  gallons  being  removed  and  dumped  upon  scows  holding 
about  450  loads  each. 

The  scows  were  towed  to  distant  points  where  the  sewage  was  pumped  into  lagoons 
provided  by  the  owner  of  the  land.  From  the  lagoons  the  concentrated  sewage  was 
bailed  into  tank  carts  and  distributed  on  land. 

The  sewage  works  when  built  consisted  of  a  separate  system,  collecting  the 
domestic  sewage  of  the  city  into  a  high  and  a  low  interceptor,  the  sewage  being  pumped 
from  the  lower  to  the  higher  at  a  suitable  point,  The  works  are  situated  about  4% 
miles  east  of  the  city  boundary  on  the  shore  of  Back  river.  The  process  of  disposal 
comprises  sedimentation,  screening,  sprinkling  filters  and  subsequent  settling  basins. 
The  ultimate  population  provided  for  was  approximately  1,000,000.  The  works  were 
well  under  construction  at  the  end  of  1913. 


438 


DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


Boston 

A  description  of  the  main  drainage  works  of  Boston  is  given  in  Part  III,  Chapter 
II,  Section  4  of  this  report. 


tSS^l&i Sooth  Metropolitan  Sewage  District 
W^s'SM  Boston  Main  Drainage  District 


SCALE  OF  MILES 

Note:-  The  darker  areas  represent  the  denser  population 


FIG.  6— BOSTON 

The  sewage  of  Boston  and  vicinity  is  discharged  through  three  principal  outlets  situated  in  the  outer  harbor. 
The  North  Metropolitan  sewage  is  passed  through  coarse  screens  and  discharged  just  beneath  the  surface  of  the 
harbor  water.  The  South  Metropolitan  sewage  is  screened  and  discharged  about  thirty  feet  beneath  the  surface. 
The  sewage  of  Boston  is  stored  in  reservoirs  and  discharged  on  outgoing  tidal  currents. 


MAIN  DRAINAGE  439 
Chicago 

Chicago  is  situated  upon  the  comparatively  low-lying  land  near  the  south  end  of 
Lake  Michigan.  The  natural  drainage  is  toward  the  lake,  which  affords  the  only 
source  of  water  supply  for  Chicago  and  its  neighboring  municipalities.  In  order  to 
protect  the  water  supply,  and  incidentally  provide  water  transportation  to  the  Missis- 
sippi river,  a  canal  has  been  built  whose  effect  is  to  reverse  the  direction  of  natural 
drainage  and  provide  means  for  carrying  away  the  sewage  of  the  city. 

The  works,  which  are  intended  for  the  sewage  of  three  million  people,  include  the 
construction  of  the  canal,  the  improvement  of  the  Chicago  river,  which,  to  all  appear- 
ances, is  a  prolongation  of  the  canal,  the  construction  of  intercepting  and  collecting 
sewers,  the  building  of  intakes  from  the  lakes  and  pumps  to  provide  the  large  supply 
of  water  needed  to  maintain  suitable  currents  in  the  canal. 

The  disposal  works  for  the  sewage  of  the  northern  and  southern  districts  and  en- 
virons are  not  yet  complete.  Some  sewage  from  urban  and  suburban  populations  dis- 
charges into  the  lake,  and  it  is  intended  that  the  pollution  of  the  lake  from  these 
sources  shall  be  prevented  by  the  construction  of  works  which  will  be  co-ordinated 
with  the  main  drainage  scheme  which  has  been  built. 

The  total  cost  of  the  work  has  been  over  $40,000,000  thus  far.  The  construction 
of  the  Chicago  drainage  canal  was  carried  on  by  a  commission  or  board  of  trustees 
known  as  the  Sanitary  District  of  Chicago.  The  district  was  organized  under  a  gen- 
eral State  law  for  the  creation  of  sanitary  districts,  passed  in  1889.  The  total  area 
covered  by  the  board's  jurisdiction  is  358.08  square  miles. 

The  main  canal  or  channel  of  the  Sanitary  District  is  28.05  miles  long.  The  first 
work  put  under  contract  was  in  1892  and  water  was  let  in  to  the  channel  January, 
1900. 

It  is  estimated  that  the  population  of  the  Sanitary  District  will  have  reached 
3,000,000  between  the  years  1920  and  1922,  and  to  dilute  the  sewage  of  3,000,000  people 
will,  under  the  State  law,  require  10,000  cu.  ft.  of  water  per  second  as  a  minimum.  The 
intended  capacity  of  the  canal  was  600,000  cu.  ft.  per  minute. 

In  a  report  of  the  Chief  Engineer  to  the  Board  of  Trustees  of  the  Sanitary  Dis- 
trict, October,  1911,  the  statement  is  made  that  it  is  questionable  whether  the  capacity 
of  the  canal  will  be  sufficient  properly  to  dilute  the  sewage  of  3,000,000  people  together 
with  the  large  quantity  of  manufacturing  wastes  that  are  discharged  from  the  sewers 
into  the  different  branches  of  the  Chicago  river. 


440         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


FIG.  6— CHICAGO 


The  crude  sewage  of  Chicago  is  discharged  into  the  Chicago  river  whose  current  has  been  reversed  and  made 
to  flow  through  a  channel  constructed  for  the  purpose  into  the  Des  Plaines  river  and  thence  to  the  Mississippi. 


MAIN  DRAINAGE  441 

The  sewage  is  discharged  into  the  Chicago  river  and  its  immediate  tributaries  in 
Chicago  in  crude  condition  and  through  numerous  outlets  some  of  which  are  very 
large.  Water  is  pumped  into  the  river  for  flushing  purposes  in  the  north  end  of  the 
city  through  a  16-ft.  conduit  connecting  with  the  lake.  The  entrance  to  the  Chicago 
river  which  is  used  for  shipping,  is  near  the  center  of  the  city.  A  pumping  station, 
discharging  into  the  canal  through  a  20-ft.  conduit  is  situated  somewhat  to  the  south 
of  the  more  thickly  built-up  section  of  the  city.  The  water  supplies  are  taken  from 
cribs  running  from  two  miles  to  four  miles  out  into  the  lake  and  at  various  points 
along  the  water  front  opposite  the  built-up  sections. 

The  Calumet  territory  is  to  the  extreme  south  of  the  city  and  is  partly  in  the 
State  of  Indiana.  The  Calumet  area  is  intersected  by  the  Calumet  river — a  small  and 
usually  sluggish  stream  whose  level  is  influenced  by  Lake  Michigan.  It  is  intended 
by  the  Sanitary  District  of  Chicago  to  construct  a  channel  with  a  capacity  of  2,000 
cu.  ft.  per  second  to  reverse  the  flow  of  the  Calumet  river  and  cause  its  waters  to  flow 
into  the  main  channel  of  the  Sanitary  District. 

The  canal  of  the  Sanitary  District  is  avowedly  an  open  sewer  in  which  the  crude 
sewage  of  Chicago  is  poured  and  diluted  with  sufficient  water  from  Lake  Michigan  to 
prevent  excessive  nuisance.  This  method  of  disposing  of  the  sewage  was  contemplated 
when  the  Sanitary  District  Act  of  1889  was  passed  by  the  State  Legislature  in  order 
that  the  Sanitary  District  of  Chicago  could  be  created.  Experience  in  Europe  and 
America  checked  by  observations  upon  the  dilution  of  that  part  of  the  sewage  of  Chi- 
cago which  had  for  some  years  been  discharged  into  the  Illinois  and  Michigan  canal 
led  to  the  opinion  that  a  flow  of  at  least  3.3  cu.  ft.  per  second  of  clean  water  should 
be  provided  for  every  thousand  people  sewering  into  the  canal.  The  question  has 
always  been  considered  from  the  standpoint  of  nuisance  and  not  as  to  whether  the 
water  was  so  polluted  as  to  destroy  fish  life  or  affect  the  health  of  persons  who  came 
in  contact  with  it.  The  minimum  figure  for  dilution  was  based  largely  on  the  assump- 
tion that  domestic  sewage  was  to  be  dealt  with  and  is  said  not  to  provide  a  wide  mar- 
gin for  industrial  wastes  or  for  the  disposal  of  deposits  of  sludge  in  the  river  or  canal. 

According  to  the  report  of  the  Chief  Engineer  for  1911,  the  oxygen  in  the  water 
of  the  canal  is  frequently  exhausted  at  Lockport  and  continues  to  be  exhausted  for 
ten  or  fifteen  miles ;  while  odors  are  distinctly  noticeable  at  Lockport  and  as  far  down 
as  Joliet,  they  are  not  considered  to  have  assumed  the  proportions  of  a  definite  nuisance. 

It  is  estimated  that  the  suspended  matter  in  the  sewage  which  is  discharged  into 
the  river  and  main  channel  from  human  sources  alone  amounts  to  over  137,000  tons 
of  dry  material,  and  of  this  about  40  per  cent,  may  settle.  Roughly  this  represents 
about  640,000  cu.  yds.  of  liquid  sludge  per  year. 


442  DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

Columbus 

The  city  of  Columbus,  Ohio,  covers  an  area  of  seventeen  square  miles,  and  in  1910 
had  a  population  of  181,548.  It  is  situated  just  cast  of,  and  opposite,  the  confluence 
of  the  Olentangy  and  Scioto  rivers.  For  a  distance  of  about  one  hundred  miles  below 
this  point,  no  water  is  taken  for  municipal  supply.    Above  the  confluence  the  Scioto 


FIG.  7— COLUMBUS 
The  sewage  works  consist  of  septic  tanks  and  sprinkling  filters. 


MAIN  DRAINAGE  443 

drains  1,050  sq.  miles  and  the  Olentangy  514  sq.  miles.  During  periods  of  dry  weather 
the  entire  flow*  of  the  Scioto  is  drawn  for  water  supplies  by  towns  above  Columbus 
and  is  returned  as  sewage.  Before  the  disposal  plant  was  built,  the  additional  dis- 
charge of  the  sewage  of  Columbus  resulted  in  stagnation  and  foul  smelling  pools. 
Similar  conditions  of  nuisance  obtained  in  Alum  Creek,  which  drains  the  extreme 
eastern  section  of  the  city  and  enters  the  Scioto  river  several  miles  below. 

Steps  were  taken  to  correct  the  polluted  condition  of  the  river  within  the  limits 
of  Columbus  in  1888,  when  an  intercepting  sewer  was  constructed  to  carry  the  sewage 
to  a  point  below  the  city.  Experimental  studies  in  the  purification  of  sewage  were 
made  between  1903  and  1905.  As  a  result  of  this  investigation  it  was  decided  to  con- 
struct a  plant  consisting  of  septic  tanks,  sprinkling  filters  and  settling  basins. 

Part  of  the  sewerage  is  on  the  combined  and  part  on  the  separate  system.  The 
maximum  capacity  of  the  main  sewer  leading  to  the  works  is  40,000,000  gallons  per 
day.  This  provides  for  the  ordinary  dry  weather  flow  and  0.02"  per  hour  of  rainfall 
over  the  drainage  area.  In  1912,  2,789,660  gallons  of  the  total  daily  amount  of  sewage 
were  pumped,  the  main  pumping  station  being  in  service  about  220  days  in  the  year. 
For  the  remainder  of  the  time  it  was  not  needed  or  was  shut  down  for  lack  of  funds. 

At  the  pumping  station  the  sewage  passes  through  two  cage  screens  with  open- 
ings of  1-inch  and  %-inch  respectively.  The  screenings  are  spread  upon  the  adjoin- 
ing land.  The  pumping  station  is  about  2.3  miles  below  the  center  of  the  city.  The  lift 
is  28  feet.  A  48-inch  cast-iron  force  main  conveys  the  sewage  from  the  pumping  sta- 
tion to  the  purification  works  a  little  over  a  mile  away.  The  disposal  works  are  sit- 
uated upon  an  area  of  flat  ground  46  acres  in  extent  surrounded  by  a  levee  for  pro- 
tection during  floods.  The  plant  cannot  be  operated  during  flood  stages  of  the  river 
as  the  elevation  of  the  filter  beds  and  settling  basins  is  below  high  water  level.  At 
such  times  the  dilution  of  the  sewage  by  the  river  water  is  so  great  that  treatment  is 
not  considered  necessary. 

The  river  varies  greatly  in  volume,  ranging  from  30  cu.  ft.  per  second  to  50,000 
cu.  ft.  per  second.  Under  dry  weather  conditions  it  is  about  equal  to  the  flow  of  sew- 
age from  the  city. 

At  the  works  the  sewage  is  delivered  to  four  primary  septic  tanks  which  have  a 
combined  capacity  of  2,840,000  gallons.  From  these  it  passes  to  two  secondary  tanks 
with  a  combined  capacity  of  5,200,000  gallons.  Each  tank  is  divided  in  two  parts  by 
a  submerged  concrete  baffle  8  ft.  high  intended  to  retard  the  motion  of  sewage  at  the 
bottom.  The  floor  slopes  to  an  open  channel  at  the  center  which  leads  to  a  blow-off 
to  the  river.    The  septic  tanks  are  not  covered.    The  combined  capacity  of  the  tanks 


444  DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

is  8,040,000  gallons  and,  as  they  are  designed  for  a  flow  of  20,000,000  gallons,  they  will 
provide  storage  for  9%  hours.    As  operated,  sewage  is  stored  for  about  8  hours. 

From  the  secondary  tanks  a  60-inch  reinforced  concrete  conduit  625  feet  long 
conveys  the  sewage  to  a  distributing  well  at  the  center  of  the  filter  beds.  These  are  in 
the  form  of  six  triangles  about  2y2  acres  each,  forming  a  hexagon.  The  sewage  is  dis- 
tributed by  nozzles  spaced  15'4"  apart.  There  are  528  nozzles  to  a  bed.  Four  of  the 
six  beds  have  been  constructed  with  a  normal  capacity  of  30,000,000  gallons  per  day. 

The  filtering  material  is  5  feet  thick  and  is  composed  of  broken  stone.  The  size 
varies  from  3  to  4  inches  for  a  foot  at  the  bottom ;  the  remainder  is  2  inches  in  diameter. 

After  passing  from  the  sprinkling  filters,  the  sewage  flows  to  two  settling  basins 
having  a  combined  capacity  of  2,000,000  gallons  and  an  area  of  two  acres  each.  When 
handling  20,000,000  gallons  of  sewage  per  day  the  period  of  flow  is  about  2y2  hours. 
The  sewage  is  conducted  away  from  the  plant  by  three  outlet  conduits  5y2  feet  in 
diameter  which  lead  to  a  chamber  containing  flap  valves  and  sluice  gates. 

The  settling  basins  are  emptied  by  a  pump  operated  by  a  gas  engine.  The  sludge 
is  not  utilized,  being  flushed  to  the  river  or  to  gravel  pits  in  the  vicinity. 

Fermentation  proceeds  at  times  so  actively  in  the  primary  tanks  as  to  interfere 
with  the  process.  The  odor  is  offensive  near  the  tanks  and  near  the  filters.  The 
sprinkling  filters  give  the  best  result  under  heads  of  4.7  and  9  feet,  discharging  for 
fifteen  minutes  under  each  head  with  fifteen  minutes  of  rest  between.  The  effluent  is 
practically  nonputrescible  but  carries  about  the  same  amount  of  sediment  as  when 
leaving  the  septic  tanks. 

Providence 

The  City  of  Providence,  with  a  population  in  1912  of  235,600,  covers  a  hilly  area 
of  18.3  square  miles  near  the  head  of  the  Providence  river  in  the  State  of  Rhode  Island. 
The  population  served  by  the  sewers  is  206,000  and  the  sewage  contains  much  manu- 
facturing waste  from  woolen  mills,  bleacheries,  dye  houses  and  jewelry  factories. 

Owing  to  the  increasing  pollution  of  the  river  and  the  several  tributaries  which 
flow  through  the  city  and  the  threatened  contamination  of  extensive  oyster  beds  along 
the  river  below  Providence  and  in  Narragansett  bay,  sewage  disposal  works  were 
constructed  after  studies  of  European  methods  of  purifying  sewage  were  carried  on 
in  1884. 

The  works  of  main  drainage  include  intercepting  sewers  which  collect  and  carry 
the  sewage  of  the  city  to  Fields  Point,  at  the  mouth  of  the  river  somewhat  below  the 
city,  where  pumps  and  a  chemical  precipitation  plant  were  originally  constructed.  In 
1912  the  amount  of  sewage  treated  was  about  21  million  gallons  per  day,  which  is  about 
6  times  the  volume  for  which  the  works  were  originally  designed. 


MAIN  DRAINAGE  445 

For  some  years  the  works  were  operated  on  the  principle  of  chemical  precipita- 
tion with  sludge  pressing.  They  have  recently  been  somewhat  reconstructed  and  the 
sewage  is  now  settled  and  treated  with  bleaching  powder  solution.  The  sludge  is 
pressed  and  the  cake  is  carried  away  by  scow.  The  effluent  from  the  settling  tanks 
is  run  into  storage  tanks  and  discharged  directly  into  the  river  on  the  ebb  tide.  The 
discharge  takes  place  beneath  about  35  feet  of  water.  The  bleaching  powder  solution 
is  used  in  the  proportion  of  about  144  pounds  of  hypochlorite  per  million  gallons  of 
sewage.   About  5.8  parts  per  million  of  available  chlorine  are  added. 

The  sludge  is  pumped  by  ejectors  to  storage  reservoirs  from  which  it  flows  by 
gravity  to  forcing  receivers  8  feet  in  diameter  by  12  feet  in  length,  which  operate 
under  60  to  80  pounds  pressure  and  feed  the  filter  presses.  The  ejectors  and  forcing 
receivers  are  run  by  air  pressure  generated  by  an  air  compressor  which  is  actuated 
by  a  motor.  There  are  18  presses  of  43  to  54  plates  each.  Cakes  are  36  inches  square 
and  from  %  to  1 14-inch  thick.  Lime  is  added  to  the  sludge  before  pressing  in  the  pro- 
portion of  79  pounds  per  thousand  gallons  of  sludge.  The  moisture  in  the  wet  sludge 
is  about  91  per  cent.  There  were  20,436  tons  of  sludge  cake  produced  in  the  year 
1912  containing  29.5  per  cent,  of  moisture. 

The  cost  of  sedimentation  and  disinfection  per  million  gallons  of  sewage  treated 
is  given  as  $2.85  and  the  cost  of  sludge  disposal  $2.49  per  million  gallons  of  sewage 
treated.  In  the  year  1912  there  were  1,758  gallons  of  sludge  produced  per  million 
gallons  of  sewage.  The  process  removes  about  48  per  cent,  of  the  suspended  matter 
from  the  sewage.  The  cubic  contents  of  the  settling  basins  up  to  the  flow  line  is  3.96 
million  gallons  and  the  capacity  of  the  storage  tanks  7,170,000  gallons.  There  were 
discharged,  without  treatment,  in  the  year  1912,  81  million  gallons  of  storm  water. 

The  total  number  of  bacteria  removed  by  the  process  varied  in  the  year  1912 
from  about  60  per  cent,  to  99.9  per  cent,  according  to  averages  stated  for  each  month. 
The  efficiency  of  the  disinfection  process,  based  on  relative  number  of  B.  coli  in  the 
sewage  and  effluent,  is  stated  as  97.4  per  cent. 

Washington 

The  city  of  Washington,  D.  C,  with  a  population  of  331,069  in  1910,  is  located 
on  the  east  side  of  the  Potomac  river,  just  above  the  mouth  of  the  Anacostia  river. 
Except  in  the  northerly  portion,  the  city  lies  on  low,  flat  ground  and  there  was  for- 
merly much  damage  done  by  flooding  during  periods  of  high  water  in  the  river.  The 
mean  range  of  tide  is  2.9  feet,  but  during  freshets  the  rise  may  be  10  or  12  feet  above 
mean  low  tide.  The  Potomac,  just  below  Washington,  drains  12,555  square  miles,  of 
which  83  drain  to  Rock  creek  and  169  to  the  Anacostia  river.   The  average  flow  dur- 


446  DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

ing  the  driest  months  of  the  year  is  2,300  cubic  feet  per  second;  during  the  wettest 
months  52,170  cubic  feet  per  second,  and  during  the  whole  year  20,600  cubic  feet  per 
second. 

The  sewerage  of  the  city  may  be  said  to  date  from  1871,  when  a  board  of  public 
works  was  created.  In  course  of  time  various  defects  developed  and  there  were  com- 
plaints from  odors  due  to  lack  of  ventilation  and  from  pollution  of  the  water  courses. 
In  1885  the  sewage  was  practically  all  discharged  at  four  outlets.  In  accordance 
with  the  recommendations  of  a  board  of  consulting  engineers  in  1890,  storm  drains 
were  constructed  in  the  low-lying  sections,  the  polluted  canals  were  filled  and  inter- 
cepting sewers  were  built  to  deliver  the  sewage  at  a  central  pumping  station  on  the 
Anacostia  river.  From  this  station  the  sewage  was  carried  by  three  siphons  of  48- 
inch  diameter  for  a  distance  of  2,680  feet  under  the  river  and  thence  by  an  outfall 
sewer  9  feet  4  inches  by  8  feet  4  inches  and  15,483  feet  long  along  the  east  shore  of 
the  Potomac  to  an  outlet  discharging  at  the  bottom  of  the  river  about  500  feet  from 
shore. 

A  large  area,  containing  a  population  of  about  30,000,  is  drained  on  the  separate 
system,  but  a  more  thickly  settled  portion,  containing  about  320,000  people,  is  sewered 
on  the  combined  plan. 

On  reaching  the  pumping  station,  the  sewage  is  passed  through  a  coarse  screen, 
a  small  sedimentation  chamber  and  a  skimming  tank  and  then  pumped  to  the  outfall. 

The  volume  of  sewage  produced  in  the  year  1912-13  amounted  to  23,518,000,000  gal- 
lons and  the  amount  of  storm  water  839.8  million  gallons.  The  sewage  pumped  is  92 
to  114  cubic  feet  per  second. 

The  average  ratio  of  sewage  to  water  is  1  to  45  in  October  and  1  to  234  in  March. 
The  minimum  amount  of  oxygen  near  the  outfall  is  about  50  per  cent,  and  in  this 
vicinity  fishing  is  good. 

Worcester 

Worcester,  one  of  the  largest  manufacturing  cities  in  the  State  of  Massachusetts, 
with  a  population  in  1910  of  145,986,  is  situated  in  a  hilly  district  whose  natural 
drainage  passes  by  several  small  streams  to  Millbrook,  which,  in  turn,  empties  into 
the  Blackstone  river,  just  south  of  the  city.  On  the  course  of  the  Blackstone  toward 
Narragansett  bay  there  is  a  considerable  fall  in  elevation  which  furnishes  power  to 
numerous  mills  with  dams  and  mill  ponds.  Opportunities  are  therefore  afforded  by 
the  river  for  the  sedimentation  of  silt  material  washed  down  from  Worcester  and  for 
evils  of  stagnation  to  occur. 

In  1867  the  Legislature  of  the  State  granted  the  city  the  privilege  of  using  the 


MAIN  DRAINAGE 


447 


FIG.  8— WORCESTER 

Part  of  the  sewage  of  Worcester  is  disposed  of  by  chemical  precipitation  and  part  by  sedimentation  followed 
by  intermittent  sand  filtration,  the  effluent  being  discharged  into  the  Blackstone  river. 


brooks  for  the  reception  of  sewage  and  the  watercourses  in  the  city  which  have  been 
used  for  this  purpose  have  been  enclosed,  the  last  section  of  the  Millbrook  covering 
being  completed  in  1894. 

Complaints  from  property  owners  on  the  Blackstone  river  below  Worcester 
began  to  be  made  in  1870  and  these  resulted  in  studies  which  were  protracted  for  many 
years.  Among  the  means  which  were  considered  for  the  protection  of  the  Blackstone 
was  the  construction  of  a  trunk  sewer  to  sea  near  Boston.    When  the  population  of 


448         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

the  city  reached  70,000  in  1886,  the  Legislature  passed  a  statute  requiring  Worcester 
to  purify  its  sewage  before  discharging  it  into  the  Blackstone  river.  After  numer- 
ous reports  from  experts  and  the  recommendation  of  various  methods  of  solving  its 
sewage  problem,  Worcester  finally  adopted  chemical  precipitation  and  intermittent 
filtration  as  the  process  for  the  disposal  of  its  sewage. 

The  first  sewers  were  built  on  the  combined  plan  and  designed  to  discharge 
into  the  Blackstone  Canal  which  extended  into  the  heart  of  the  city.  After  the  canal 
had  ceased  to  be  used  for  boats,  the  city  took  it,  walled  it  up,  arched  it  in  and  called 
it  the  Millbrook  sewer. 

About  1897  in  order  that  the  purification  plant  might  be  operated  to  better  ad- 
vantage, it  was  decided  to  make  a  complete  separation  of  sewage  and  the  surface 
water  in  the  outlying  districts  and  to  build  interceptors  in  the  main  and  business 
parts  of  the  city ;  one  on  each  side  of  the  Millbrook  sewer  and  one  extending  into  the 
business  part  of  the  city.  The  three  interceptors  were  combined  and  connected  with 
the  main  sewer  which  extended  to  the  purification  plant.  The  dry-weather  flow  was 
taken  by  the  interceptors  and  the  Millbrook  sewer  was  left  for  the  flow  of  the  water 
from  ponds  and  other  natural  tributaries  to  the  north  of  the  city.  At  times  of  storm, 
the  interceptors  take  the  first  street  washings  up  to  their  capacity,  the  excess  over- 
flowing to  Millbrook  creek. 

At  the  disposal  works  the  sewage  is  passed  through  grit  chambers  which  remove 
about  one-tenth  of  a  cubic  yard  of  solid  matter  per  million  gallons  of  sewage,  the 
deposits  being  disposed  of  on  waste  land.  After  passing  through  the  grit  chambers, 
the  sewage  is  treated  either  by  intermittent  sand  filtration  or  by  chemical  precipita- 
tion with  milk  of  lime,  the  quantity  of  sewage  treated  in  each  way  during  the  year 
1912  having  been  11,500,000  gallons  per  day  by  chemical  precipitation  and  about  4.3 
million  gallons  per  day  by  filtration.  The  quantity  of  sewage  which  can  be  treated  on 
the  filters  is  limited  by  the  capacity  of  the  area  required.  The  strongest  sewage  is 
selected  for  filtration,  for  the  reason  that  this  method  gives  a  higher  degree  of  purifi- 
cation than  does  chemical  precipitation.  The  area  available  for  filtration  is  about  73 
acres  and  the  flow  per  day  about  58,000  gallons  per  acre.  Before  the  sewage  is  passed 
upon  the  sand  filters,  it  flows  through  one  of  two  settling  basins,  giving  a  detention 
period  of  one-half  hour. 

The  sludge  produced  in  this  way  is  about  3,750  gallons,  containing  95  per  cent,  of 
moisture,  per  million  gallons  of  sewage.  In  the  year  1912  solid  matter  to  the  extent 
of  320  cubic  yards  per  acre  or  15  cubic  yards  per  million  gallons  of  sewage  filtered  was 
scraped  from  the  filters.    The  purification  effected  by  the  sand  filters,  measured  by  the 


MAIN  DRAINAGE  449 

albuminoid  ammonia,  amounts  to  about  87.1  per  cent,  and  measured  by  the  dissolved 
organic  matter  66.7  per  cent. 

In  the  year  1912  chemical  precipitation  required  1,902  tons  of  lime  and  the  sludge 
produced  amounted  to  4,551  gallons  per  million  gallons  of  sewage  treated.  Most  of 
the  sludge  is  pressed  in  filter  presses  with  the  formation  of  about  11,000  tons  of  cake 
which  is  hauled  to  a  sludge  dump.  Farmers  in  the  vicinity  take  a  small  proportion  to 
be  used  as  fertilizer.  The  efficiency  of  the  precipitation  process  as  shown  by  the  albumi- 
noid ammonia  is  a  removal  of  77.8  per  cent,  of  the  suspended  organic  matter. 

The  cost  of  chemical  precipitation  and  sludge  disposal  in  the  year  1912  was  $8.44 
per  million  gallons.  The  purification  effected  by  the  entire  plant,  as  measured  by  the 
albuminoid  ammonia,  amounted  to  57.7  per  cent,  and  by  suspended  organic  matter 
87.2  per  cent. 

There  are  said  to  have  been  no  recent  complaints  from  the  residents  of  the  towns 
below.  It  is  expected,  however,  that  with  the  rapid  growth  of  population  and  manu- 
facturing, the  plant  will  not  be  able  adequately  to  cope  with  the  sewage  problem  and 
that  steps  will  have  to  be  taken  toward  a  larger  plant  along  lines  of  greater  efficiency 
as  indicated  by  the  results  of  experiments  which  have  recently  been  conducted. 

Berlin 

Berlin  is  situated  in  the  midst  of  a  flat,  low-lying,  sandy  plain  whose  natural 
drainage  system  includes  the  river  Spree  and  a  large  number  of  small  lakes.  The  public 
waterways  include  many  miles  of  artificial  canals.  The  city  is  divided  into  12  parts 
for  the  purpose  of  sewerage  with  a  central  collecting  station  at  the  lowest  point  in 
each.  From  this  lowest  point  the  sewage  is  pumped  to  farm  lands  which  lie  at  a  dis- 
tance to  the  north  and  south  of  the  city. 

The  Berlin  sewerage  system  serves  the  city  of  Berlin,  proper,  and  certain  parts  of 
the  contiguous  suburbs.  At  the  close  of  the  fiscal  year  1912,  the  territory  served  cov- 
ered 15,000  acres  and  had  a  population  tributary  to  the  sewers  of  2,182,391.  The  volume 
of  sewage  was  80  million  gallons  per  day,  which  is  equivalent  to  36.7  gallons  per  capita 
per  24  hours.   The  sewage  is  collected  on  the  combined  plan. 

The  sewage,  on  arriving  at  the  central  collecting  stations,  is  passed  through  grit 
chambers  and,  in  some  cases,  screens,  before  being  pumped  to  the  farms  for  disposal. 
In  1912  the  sand  and  other  material  removed  in  the  grit  chambers  amounted  to  3,400 
cubic  yards.  The  sewage  is  pumped  through  force  mains  to  the  irrigation  fields  which 
lie  to  the  north  and  south  of  the  city  at  an  elevation  of  from  65  to  100  feet  above  the 
level  of  the  pumping  stations.    In  1912  there  were  0.84  million  gallons  of  sewage 


450        DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

from  the  suburbs  and  29,270  million  gallons  of  sewage  from  Berlin,  making  nearly 
30,000  million  gallons  in  all  pumped  to  the  farms. 


FIG.  9— BERLIN 

The  sewage  is  pumped  to  extensive  areas  of  land  to  the  north  and  south  of  the  city  where  it  is  utilized  in  the 
cultivation  of  crops. 


MAIN  DRAINAGE  451 

The  force  mains  vary  from  5  to  17  miles  in  length.  The  usual  construction  is 
welded  wrought  iron  socket  pipe  in  lengths  of  about  20  feet. 

The  sewage  is  discharged  through  sluice  valves  upon  the  sewage  fields  at  points 
from  which  it  can  flow  by  gravity  until  finally  disposed  of.  The  method  of  applica- 
tion varies  with  the  formation  of  the  ground.  The  deeper  slopes  are  grown  to  meadow. 
The  lesser  inclines  are  laid  out  in  vegetable  beds  and  the  levels  are  banked  up  into 
settling  pools.  The  sewage  is  distributed  from  the  sluice  valves  partly  through  clay 
pipes,  but  mostly  through  open  ditches  about  iy2  feet  deep.  In  the  settling  pools  the 
sewage  is  allowed  to  fill  to  a  depth  of  about  1  foot,  whereupon  it  is  turned  off  and  the 
contents  allowed  to  seep  into  the  ground.  That  which  is  applied  to  the  meadows  and 
vegetable  beds  is  supplied  as  rapidly  as  the  earth  will  absorb  it. 

The  settling  pool  method  of  disposal  is  employed  only  in  winter.  The  ground 
covered  by  the  pools  is  usually  sown  to  grain  in  the  spring.  The  fields  are  drained  by 
pipes  generally  laid  about  4  feet  below  the  surface,  this  depth  having  proved  suffi- 
cient to  cleanse  the  water  and  is  found  suitable  for  discharging  the  effluent  into  the 
public  waterways. 

When  the  present  system  of  sewage  disposal  was  adopted,  it  was  thought  by  some 
that  the  earth  would  soon  become  saturated  with  the  sewage  matters,  but  this  is  said 
not  to  have  proved  to  be  the  case.  The  sewage  farms  are  about  43,400  acres  in  extent 
and  sewage  is  regularly  applied  to  about  one-half  of  this  territory.  About  16,000  acres 
are  laid  out  in  vegetable  beds  and  settling  pools  and  about  5,000  acres  are  in  meadow. 
The  balance  includes  38  acres  of  fields  where  pisciculture  is  carried  on ;  247  acres  are 
devoted  to  forestry. 

The  water  which  drains  from  the  sewage  fields  is  subjected  to  constant  chemical 
and  biological  examination.  Tests  are  also  made  periodically  of  the  waters  of  the 
Spree.  The  health  of  the  people  who  live  on  the  sewage  farms  is  carefully  watched. 
The  records  are  published  annually  and  confirm  the  belief  that  the  sewage  fields  are 
satisfactory  from  a  hygienic  standpoint. 

Upon  its  passage  through  the  earth,  the  sewage  parts  with  most  of  its  organic  im- 
purities, but  the  effluent  sometimes  contains  more  nitrogen  than  is  commonly  met  with 
in  natural  streams.  This  has  encouraged  the  growth  of  algae  to  such  an  extent  that 
some  of  the  water  courses  have  become  partly  closed.  When  the  algae  die  and  decom- 
pose, minute  forms  of  animal  life  feed  upon  them  and  the  total  mass  of  these  living 
organisms  may  become  great. 

There  are  no  better  farms  from  which  to  judge  the  possible  profit  to  be  realized 
from  applying  sewage  to  land.  About  one-half  of  the  fresh  vegetables  consumed  in  the 
city  of  Berlin  is  said  to  be  derived  from  the  sewage  farms. 


452         DATA  RELATING  TO  THE  PROTECTION  OP  THE  HARBOR 

The  cost  of  construction  of  the  sewage  works,  including  street  sewers,  pumping 
stations  and  force  mains,  was  $24,900,000  up  to  the  end  of  the  fiscal  year  1912.  The 
sums  expended  on  the  farms,  including  purchase  price,  drainage  and  carting,  was 
$18,160,000.  The  total  indebtedness  was  about  $26,130,000,  or  $12.62  per  head  of  the 
population  of  Berlin  concerned. 

The  gross  receipts  from  the  leasing  of  fields,  from  live  stock,  fisheries,  etc.,  was 
$2,020,000  and  the  gross  expenditures  $1,844,000.  From  these  figures  it  would  appear 
that  there  was  a  profit  of  $177,200.  From  this  apparent  profit  there  must  be  deducted 
the  cost  of  administration  for  the  farms,  the  cost  of  new  buildings,  interest  on  loans 
and  sinking  fund  charges,  amounting  to  $1,181,000,  leaving  a  deficit  of  $843,000. 

Cologne 

The  sewage  disposal  works  for  Cologne  are  situated  in  the  suburb  of  Niehl,  about 
three  miles  below  the  city  and  about  90  miles  above  the  Netherlands.  The  population 
is  about  540,000  and  the  volume  of  sewage  14.5  million  gallons  per  day.   At  low  water 


FIG.  10— COLOGNE 

At  the  disposal  works  the  sewage  is  passed  through  fine  screens  and  then  through  a  basin  in  which  it  can  be 
disinfected  in  case  of  necessity,  the  effluent  being  discharged  at  the  bottom  of  the  river  Rhine. 


MAIN  DRAINAGE  453 

level  the  Rhine  flows  at  the  rate  of  17,860  million  gallons  per  24  hours,  so  that  the  rate 
of  dilution  is  about  1  of  sewage  to  1,230  of  water. 

The  sewage  is  passed  through  grit  chambers  and  screens  and  can,  in  case  of  neces- 
sity, be  conducted  through  a  settling  basin  where  disinfectants  can  be  applied.  The 
discharge  takes  place  through  a  submerged  outlet  about  10  feet  beneath  the  surface  of 
the  river. 

The  feature  of  greatest  interest  in  connection  with  the  Cologne  works  is  the 
screening  process.  There  is  a  coarse  screen  which  catches  large  floating  substances 
such  as  rags,  paper,  straw,  etc.,  with  0.6-inch  openings  and  a  fine  screen  with  openings 
of  0.1  inch  to  collect  the  smaller  floating  material.  The  velocity  through  the  screen  is 
0.1  inch  per  second. 

The  screen  is  of  the  fixed  bar  type  placed  at  an  inclination  in  the  sewage.  It  is 
cleaned  by  steel  brushes  which  travel  uninterruptedly  from  the  bottom  upward  and 
remove  the  solid  matters  collected  to  a  conveyor  belt  which  empties  into  a  car  and  is 
pushed  to  manure  pits  situated  nearby.  The  screenings  are  taken  away  by  farmers  in 
the  vicinity. 

After  the  sewage  is  passed  through  the  fine  screens,  it  flows  through  the  settling 
basins  which  consist  essentially  of  enlargements  of  the  effluent  channel.  The  rate  of 
flow  through  the  settling  basin  is  1.5  inches  per  second. 

A  project  has  been  prepared  for  the  reconstruction  of  the  works.  It  is  intended 
that  the  new  installation  shall  have  two  screens  such  as  are  used  at  Dresden,  an  en- 
larged grit  chamber,  eight  sedimentation  tanks  and  twenty  sludge-drying  beds.  The 
new  plant  will  be  built  in  connection  with  a  refuse  destructor,  the  entire  sanitary  depot 
resembling  that  at  Dresden. 

Dresden 

The  city  of  Dresden,  with  a  population  of  about  560,000,  is  situated  on  the  Elbe  at 
a  good  elevation  above  the  river.  The  sewers  are  of  the  combined  type,  discharging 
the  excess  of  storm  water  to  the  river  by  overflows  and  carrying  the  dry-weather  flow 
and  four  to  five  times  this  volume  of  water  at  periods  of  storm  to  treatment  works. 
The  dry-weather  flow  of  sewage  is  about  26  million  gallons  per  day. 

The  disposal  works  are  situated  about  three  miles  below  the  city  and  consist  of 
a  grit  chamber,  screens  and  pumps,  the  latter  being  used  only  at  high  stages  of  the 
river.  The  usual  outlet  is  situated  at  the  bottom  of  the  river  in  midstream.  During 
flood  stages  of  the  river,  when  pumping  is  resorted  to,  the  discharge  takes  place  from 
outlets  at  the  river  bank. 

The  disposal  works  include  grit  chambers,  which  are  cleaned  by  a  bucket  ele- 


454  DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

vator,  the  deposits  being  utilized  for  raising  the  level  of  low-lying  land.  After  leav- 
ing the  grit  chambers,  the  sewage  passes  through  coarse  screens  with  openings  of 
about  3  inches.  The  main  purification  takes  place  in  Riensch  screens,  of  which  four 
were  in  operation  in  1913.  The  screen  surfaces  are  metal  disks  with  openings 
1.2x0.08  inches  in  diameter.    The  disks,  whose  outside  diameter  is  about  26  feet,  are 


FIG.  11— DRESDEN 

The  sewage  is  collected  to  disposal  works  where  it  is  passed  through  fine  screens  and  then  discharged  at  the 
bottom  of  the  Elbe.   The  screenings  are  used  for  manure. 


inclined  at  an  angle  of  about  15  degrees  and  have  about  two-thirds  of  their  surfaces 
submerged. 

The  cleaning  is  done  by  brushes  ingeniously  arranged  to  remove  the  material 
taken  from  the  sewage.  By  means  of  a  chute  and  elevator,  the  screenings  are  taken 
out  of  the  building  and  disposed  of  as  manure.  About  20  to  26  cu.  yds.  of  screenings 
are  produced  per  day,  containing  about  80  per  cent,  of  liquid.    The  Government  re- 


MAIN  DRAINAGE  455 

quires  that  about  23.4  cu.  yds.  of  sewage  solids  shall  be  taken  out  of  the  sewage  per 
day  before  the  effluent  is  discharged  into  the  river. 

Each  screen  has  its  own  intake  and  outlet  controlled  by  gates  and  can  be  used 
separately,  or  with  the  others.  A  complete  revolution  of  the  disk  takes  place  in  from 
2  to  3  minutes.  Each  disk  contains  230,000  openings.  The  total  area  of  openings  pro- 
vided is  150,640  sq.  ft.  for  a  flow  up  to  0.14  cu.  ft.  per  second.  About  2y2  H.  P.  is 
required  for  the  operation  of  each  disk.  The  loss  of  head  produced  by  the  flow  of 
water  through  the  screening  disks  varies  between  2  and  10  inches. 

Essen 

The  river  Emscher  is  a  small  tributary  of  the  Rhine  and  the  Emscher  District 
covers  an  area  of  about  318  square  miles,  containing  a  number  of  cities  and  towns 
and  a  total  population  in  1913  of  about  2,000,000. 

The  district  is  low  with  little  natural  slope.  Unsatisfactory  conditions  of  drain- 
age resulted  from  the  topography  and  these  were  made  worse  by  the  sinking  of  the 
land  through  mining  operations  beneath.  With  the  exception  of  Dortmund,  which 
possessed  sewage  disposal  works,  the  municipalities  in  the  Emscher  District  until  re- 
cently were  without  satisfactory  means  either  of  drainage  or  sewage  disposal. 

In  1904  a  law  was  passed  to  provide  for  the  regulation  of  the  natural  drainage 
and  purification  of  the  sewage  in  the  District  of  the  Emscher  and  authorizing  the  for- 
mation of  an  association  or  commission  to  carry  out  the  necessary  works. 

Extensive  works  were  undertaken  to  improve  the  natural  drainage.  The  sewage, 
after  the  removal  of  as  much  of  the  suspended  matter  as  it  was  practicable  to  take  out 
by  means  of  settling  basins,  was  discharged  into  the  open  water  courses. 

A  new  type  of  settling  basin  which  was  invented  to  treat  the  sewage  is  known  as 
the  Emscher  or  Imhoff  tank.  The  Emscher  tank  consists  of  two  deep  settling  basins, 
one  within  the  other.  The  sewage  passes  through  the  inner  tank,  the  suspended  mat- 
ters settling  to  the  bottom  and  passing  through  an  opening  to  the  larger  tank  below. 
Fermentation  of  the  solids  takes  place  in  the  lower  tank,  which  is  cleaned  at  long  in- 
tervals and  then  only  to  such  an  extent  as  is  necessary  in  order  to  remove  the  fer- 
mented sludge  which  is  ready  to  be  taken  out.  Large  quantities  of  gas  are  produced 
and  escape  through  suitably  arranged  outlets. 

By  fermentation,  the  consistency  of  the  sludge  is  changed  to  a  state  in  which  it 
readily  and  quickly  parts  with  its  liquid  when  placed  upon  a  filter.  When  drawn 
from  the  tanks  the  fresh  sludge  contains  75  per  cent,  of  liquid  and  this,  by  drying 


456  DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

upon  coarse  filters  exposed  to  clear  weather  for  four  or  five  days,  is  reduced  to  50  or 
60  per  cent. 

The  sludge  is  withdrawn  from  the  tanks  without  removing  the  supernatant  sew- 
age, a  sludge  pipe  extending  from  the  bottom  to  the  point  of  outlet  which  is  situated 
sufficiently  below  the  level  of  the  sewage  to  provide  the  necessary  hydraulic  head. 

The  fermented  sludge  is  odorless  and,  after  drying,  may  be  used  to  raise  the  level 
of  low-lying  land.  The  effluent  is  discharged  into  the  open  water  courses  in  the  dis- 
trict, all  of  which  are  closely  fenced  in.  The  sewage,  although  putrescible,  is  not  any- 
where in  an  actively  fermenting  condition.  The  tanks  are  sometimes  located  close  to 
built-up  sections  of  cities  and  there  is  said  to  be  no  cause  for  objection.  The  gases 
given  off  consist  largely  of  carbon  dioxide  and  methane,  both  of  which  are  odorless. 
The  works  are  uncovered. 

The  Emscher  tanks  remove  about  90  to  95  per  cent,  of  the  suspended  matters 
which  are  capable  of  settling  from  the  sewage,  the  usual  period  of  sedimentation  being 
about  two  hours. 

The  sewage  is  collected  through  combined  sewers  from  which  factory  wastes  are 
not  excluded. 

The  drainage  board  is  charged  not  only  with  the  regulation  of  the  natural  drain- 
age and  the  purification  of  the  sewage,  so  far  as  construction  is  concerned,  but  it  is 
charged  with  the  duty  of  operating  the  works  after  they  are  built.  The  board  has  the 
right  to  acquire  land,  collect  the  taxes  to  pay  the  interest  on  the  cost  of  construction 
and  operation  and  has  complete  autonomy  of  administration. 

According  to  the  original  plans,  the  work  in  the  Emscher  District  was  to  cost 
$6,750,000,  but  subsequent  estimates  have  increased  this  amount  to  $8,100,000.  Of  this 
sum  three-quarters  had  been  expended  in  1906.  It  is  expected  that  the  sums  spent  for 
the  purification  plants  will  amount  to  about  $1,665,000,  which  is  about  one-half  of 
the  total  spent  by  the  board  for  all  purposes.  Nineteen  purification  plants  were  in 
operation  in  1913,  with  770,000  inhabitants  connected  to  the  tributary  sewers.  Two 
additional  plants  for  the  sewage  of  66,000  inhabitants  were  expected  to  be  completed 
in  a  short  time  and  7  additional  plants  for  the  sewage  of  347,000  inhabitants  were  to 
be  built  within  a  year.  The  total  number  of  plants  in  the  district  anticipated  by  the 
end  of  1914  would  be  28,  and  these  would  serve  for  the  sewage  of  about  1,200,000 
inhabitants. 


MAIN  DRAINAGE 


457 


Frankfort 

The  works  at  Frankfort  are  situated  on  the  banks  of  the  river  Main,  three  miles 
in  a  direct  line  from  the  Cathedral,  which  may  be  taken  as  the  center  of  the  city.  The 
population  is  about  400,000.  The  dry-weather  flow  of  sewage  is  about  58  gallons  per 
capita,  or  about  24  million  gallons  per  24  hours.  The  capacity  of  the  works  is  six 
times  the  dry-weather  flow. 


FIG.  12— FRANKFORT 

The  sewage  is  collected  to  a  central  depot  (where  garbage  is  also  disposed  of)  and  is  passed  through  fine  screens 
and  settling  basins  before  being  discharged  at  the  bottom  of  the  river  Main.  The  screenings  and  sludge  after  drying 
are  burnt  in  the  garbage  destructor. 


The  river  at  the  works  is  less  than  500  feet  wide  and  is  a  rather  turbid,  navigable 
stream  with  a  rapid  current.  The  amount  of  dilution  at  low  stages  is  about  1  part  of 
sewage  to  130  parts  of  water.  At  average  stages,  this  ratio  is  1  to  300  and  at  high 
water  about  1  to  1700.  During  flood  stages  of  the  river,  the  effluent  from  the  works 
has  to  be  pumped. 


458         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

Three  essential  features  connected  with  the  Frankfort  works  deserve  to  be  men- 
tioned :  The  rotary  screens,  the  settling  basins  and  the  treatment  of  the  sludge.  The 
sewage  is  passed  through  grit  chambers  which  are  cleaned  by  dipper  dredges  discharg- 
ing through  a  chute.  The  grit  is  transported  a  short  distance  by  cars  to  be  finally  dumped 
upon  land.  The  screens  consist  of  horizontally-placed  wheels  with  five  sets  of  vanes 
with  spokes  three-eighths  of  an  inch  apart,  which  revolve  in  the  sewage  like  an  under- 
shot water-wheel  only  against,  and  not  with,  the  current.  The  sewage  flows  between 
the  bars,  leaving  the  suspended  matter  caught  on  the  revolving  screen.  The  rakes 
revolve  once  in  about  minutes. 

The  solids  removed  by  the  screens  are  scraped  from  the  vanes  by  an  automatic 
cleaning  device  which  delivers  them  to  a  traveling  belt.  The  screenings  are  pressed  by 
hydraulic  power  and  burnt  in  a  nearby  refuse  destructor. 

The  settling  basins  are  fourteen  in  number  and  are  shaped  somewhat  like  the  hull 
of  a  ship.  They  are  provided  with  scum  boards  to  hold  back  the  grease.  Care  has  been 
taken  to  so  incline  the  bottom  that  the  sludge  will  flow  to  the  outlet  with  little  or  no 
hand  assistance.    The  basins  are  lined  with  glazed  tile. 

When  the  settling  basins  are  cleaned,  the  sludge  is  pumped  by  means  of  compressed 
air  to  overhead  reservoirs  from  which  it  feeds  by  gravity  to  the  centrifugal  driers,  a 
short  distance  away.  These  machines  which  revolve  at  great  velocity  upon  horizontal 
axes  receive  a  constant  supply  of  sludge  and  yield  a  partly  dried  sludge  and  an  offensive 
liquid.  The  moisture  content  is  reduced  from  about  90  to  about  60  per  cent.  There  are 
eight  machines  with  a  capacity  of  3.9  cubic  yds.  per  hour  each.  The  sludge  which 
emerges  from  the  centrifugal  machines  passes  through  long  cylindrical  rotary  driers 
heated  to  about  572  degrees  Fahrenheit  where  the  moisture  content  is  reduced  to  about 
20  per  cent.   The  sludge  is  finally  burned. 

The  works  reduce  the  suspended  matter  in  the  sewage  from  about  500  to  100  parts 
per  million,  of  which  about  65  per  cent,  is  removed  by  sedimentation. 

Hamburg 

Hamburg,  although  termed  a  seaport,  is  situated  on  the  river  Elbe,  65  miles  from 
the  ocean.  Much  of  the  land  is  low.  The  Elbe  flows  through  several  channels  at  this 
point  and  is  joined  by  other  and  smaller  rivers.  The  water  is  turbid,  especially  after 
rains. 

The  sewage  is  collected  in  a  combined  system  of  sewerage,  the  dry-weather  flow 
being  conveyed  to  the  main  treatment  works  and  outlets  and  the  storm  flow  being  dis- 
charged by  overflows  into  the  canals  which  intersect  the  city  in  many  directions.  The 


MAIN  DRAINAGE  459 

population  is  about  960,000  and  the  volume  of  sewage  discharged  through  the  outfall 
works  amounts  to  about  115  million  gallons  per  day. 

Although  unfavorably  situated  for  drainage,  Hamburg  is  one  of  the  most  com- 
pletely and  efficiently  sewered  cities  in  Europe.  In  accordance  with  a  comprehensive 
drainage  plan,  the  sewage  is  carried  to  two  principal  points  for  treatment  and  dis- 
charge. The  treatment  consists  in  passing  the  sewage  through  grit  chambers  and 
screens.   It  is  then  allowed  to  empty  into  the  Elbe  through  submerged  outlets. 


FIG.  13— HAMBURG 

Large  grit  chambers  and  fine  screens  are  employed  at  the  two  disposal  stations  at  Hamburg,  the  solid  material 
removed  being  carried  away  by  boats  to  farm  lands. 

The  screens  are  of  the  endless  belt  type  and  are  cleaned  by  automatic  rakes  which 
remove  the  screenings  to  a  short  belt  conveyor  which  empties  the  material  into  cars. 
The  cars  are  pushed  by  hand  a  short  distance  to  chutes  which  discharge  into  barges. 
The  screenings  are  used  by  farmers.  The  space  between  the  bars  at  the  older  and  larger 
screen  station  is  0.6  inch.   The  new  screens  have  spaces  of  0.4  inch. 

The  range  of  tide  at  Hamburg  is  6.2  feet.  The  outlets  of  the  works  are  closed  at 
high  stages  of  tide  and  opened  again  when  the  tidal  level  falls. 


460         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

The  older  and  larger  grit  chamber  and  screening  station  is  covered  by  an  orna- 
mental brick  building  and  is  situated  in  the  built-up  portion  of  Hamburg  close  to  the 
city  of  Altona  which  immediately  adjoins  it,  There  is  no  nuisance  from  odor  in  the 
vicinity  of  the  works.  By  close  inspection  of  the  river,  solid  particles,  recognizable 
as  of  sewage  origin,  can  be  seen  rising  to  the  surface  of  the  river  and  at  certain 
seasons  the  presence  of  gulls  indicates  where  the  outlets  are  located.  The  canals  and 
waterways  of  the  city  are  attractively  clean. 

Copenhagen 

Copenhagen  is  situated  on  the  east  coast  of  Sealand,  the  largest  part  of  the  town 
being  built  on  the  main  island,  while  the  suburbs  "Christianshavn"  and  "Sundby" 
occupy  the  north  end  of  the  island  "Aniager"  (Amak).  The  narrow  water  between 
Amager  and  Sealand  has  in  course  of  time  been  converted  into  the  harbor  of  Copen- 


FIG.  14— COPENHAGEN 


Two  main  outlets  are  provided  for  the  discharge  of  the  sewage  at  sea,  the  principal  one  being 

about  a  mile  from  shore. 


MAIN  DRAINAGE  461 

hagen.  The  east  coast  of  Amager  faces  that  part  of  the  Sound  which  is  called  "Kon- 
gedybet"  (the  Kings  Deeps)  and  is  the  main  traffic  route,  with  water  depths  from 
30  to  40  feet.  To  a  distance  of  more  than  3,000  feet  from  the  shore,  however,  the 
water  is  very  shallow.  There  is  no  tide  in  the  Sound,  but  according  to  the  influence 
of  the  wind  the  water  occasionally  rises  to  4  feet  above  or  falls  to  3  feet  below  mean 
sea  level.  These  differences  in  the  water  level  cause  almost  constant  currents  running 
through  the  Kings  Deep  in  alternating  directions.  They  also  cause  currents,  though 
somewhat  weaker,  through  the  main  harbor. 

From  ancient  times  the  sewage  of  Copenhagen  was  led  to  the  harbor  in  open  chan- 
nels along  the  streets  and  it  was  not  until  the  middle  of  the  past  century  that  a 
project  for  main  drainage  was  taken  under  consideration. 

The  first  sewers  were  on  the  combined  plan,  and  the  connection  of  waterclosets  was 
forbidden  by  law.  Nevertheless,  the  harbor  became  grossly  polluted  and  a  general 
nuisance  resulted. 

About  1890  it  was  resolved  to  build  a  system  of  intercepting  sewers  and  pumping 
stations  (after  the  plans  of  the  former  Chief  City  Engineer,  Mr.  Ambt)  in  order  to 
intercept  the  sewage  and  pump  it  to  an  outfall  in  the  Kings  Deep  and  in  this  way  bet- 
ter the  conditions  so  that  waterclosets  could  be  connected,  which  at  that  time  was 
generally  demanded  by  public  opinion.  A  part  of  the  works  were  executed  in  1892, 
but  the  bulk  of  it  was  not  taken  in  hand  before  1897.  It  was  completed  in  1901.  The 
population  was  476,806  at  this  time. 

The  works  are  shown  on  the  map,  and  as  will  be  seen  there  are  three  pumping 
stations:  The  main  station  ( "Hovedkloakpumpestation" )  at  Klevermarkevej  on 
Amager,  and  two  substations,  one  ("Nordre  Kloakpumpestation")  near  the  free  harbor 
in  the  northern  part  of  the  town,  and  another  ("Vestre  Kloakpumpestation")  at  Vester- 
bro  in  the  southwestern  part. 

The  sewage  flows  by  gravity  to  the  pumping  stations,  in  intercepting  sewers,  shown 
on  the  map  by  red  lines.  They  are  laid  as  near  the  harbor  as  possible.  There  are 
two  intercepting  sewer  mains  leading  to  the  main  pumping  station,  one  from  the  center 
of  the  town,  the  other  from  the  southwestern  part.  Both  of  these  cross  the  harbor  in 
inverted  siphons,  the  southern  one  of  which  is  made  of  steel  riveted  pipes  laid  in  a 
trench  at  the  bottom  of  the  harbor  and  protected  by  cement  mortar,  while  the  northern 
one  is  made  of  cast-iron  pipes  laid  in  a  tunnel  under  the  harbor. 

The  intercepting  sewer  mains  are  from  2y2  to  6  ft.  in  diameter.  At  the  pumping 
station  the  bottoms  of  the  sewers  are  about  13  ft.  below  mean  sea  level.  From  this 
depth  the  water  is  pumped  to  the  outfall  through  a  double  force  main,  the  land  sec- 
tion of  which  is  of  cast-iron  pipe,  while  the  part  under  the  sea  is  of  wood  stave  pipe. 


462  DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

The  two  substations  have  their  own  systems  of  intercepting  sewers.  From  these 
stations  the  sewage  is  pumped  through  force  mains,  shown  on  the  map  in  red  lines,  to 
the  nearest  point  on  the  main  intercepting  sewers,  from  whence  it  flows  by  gravity  to 
the  main  pumping  station  and  is  pumped  once  more  to  the  outlet. 

The  intercepting  sewers  and  pumping  stations  are  constructed  to  receive  and  deal 
with  twice  the  maximum  dry-weather  flow.  When  during  rains  the  flow  exceeds  this 
quantity,  the  surplus  goes  directly  into  the  harbor  through  storm  overflows. 

The  outlet  is  situated  nearly  one  English  mile  from  the  shore  at  a  point  where 
there  is  33  feet  of  water  at  mean  sea  level.  The  total  distance  from  the  pumping  sta- 
tion to  the  outlet  is  9,200  feet.  The  outfall  section  is  built  of  wood  staves  which  are 
kept  together  by  wooden  ties  or  hoops.  They  are  laid  down  in  a  trench  in  the  bottom 
of  the  sea  and  covered  with  3  feet  of  sand  filling.  The  outlets  are  made  by  opening 
the  pipes  at  the  top  and  building  two  timber  walls  up  to  a  foot  above  the  bottom.  Each 
pipe  has  an  opening  27  feet  long  and  6  inches  wide,  causing  the  sewage  to  discharge 
in  a  thin  sheet,  which  is  easily  caught  by  the  current  and  diffused  with  the  sea  water. 
There  are  almost  constant  currents  through  the  Kings  Deep  with  an  average  velocity 
of  nearly  one  mile  an  hour.  As  compared  with  the  tidal  currents  ordinarily  en- 
countered on  the  English  Coast,  these  currents  have  the  advantage  of  running  for 
several  days  in  the  same  direction  and  therefore  will  take  the  sewage  to  such  a  dis- 
tance that  there  is  no  danger  of  its  returning  when  the  current  changes.  The  outlet 
has  now  been  in  use  for  several  years  without  causing  the  slightest  nuisance. 

Vienna 

Vienna  is  situated  on  the  left  bank  of  the  Danube,  which  is  here  about  1,000  ft. 
wide,  and  in  1911  had  a  population  of  2,004,000.  The  river  has  an  average  volume  of 
flow  of  about  27,750  million  gallons  per  day.  A  part  of  the  city  is  situated  on  an  island 
formed  by  the  Little  Danube.  Although  intercepted  with  water-courses,  the  natural 
drainage  is  relatively  good. 

The  sewage  is  collected  upon  the  combined  plan.  There  is  much  drainage  from 
uplands  lying  to  the  west  which  is  carried  through  the  city  by  means  of  large  culverts. 
Many  combined  sewers  emptying  directly  into  the  Danube  or  Little  Danube  have  been 
intercepted  by  large  sewers  along  the  banks  and  now  discharge  into  the  Little  Danube 
below  the  city.  It  is  intended  to  extend  the  works  in  order  that  they  may  discharge 
into  the  main  stream  at  a  more  distant  point  after  screening.  The  dry  weather  flow 
of  sewage  is  24  gallons  per  capita  per  24  hours  and  the  sewerage  works  are  designed 
on  the  theory  that  one-half  of  the  total  quantity  will  flow  off  in  10  hours. 


MAIN  DRAINAGE 


463 


FIG.  16— VIENNA 

The  sewage  is  collected  by  interceptors  running  parallel  to  the  banks  of  the  water-courses,  and  discharged 
through  one  main  outlet  into  the  Danube  after  passing  through  grit  chambers.  The  large  flow  of  this  stream  is 
favorable  to  disposal  by  dilution  and  renders  further  treatment  unnecessary.    No  nuisance  is  produced. 


In  extensions  of  the  sewerage  system  now  being  planned  preparation  is  made  for 
the  drainage  of  a  population  of  about  5,000,000,  which  it  is  expected  will  be  present  if 
the  recent  rate  of  increase  continues. 

At  the  present  time  the  sewage  from  a  population  of  1,400,000  is  carried  to  the 
Little  Danube  outlet.  There  is  one  main  outlet,  the  flow  being  49.4  cu.  ft.  per  second 
in  dry  weather  or  32  million  gallons  per  day.  Numerous  storm  overflows  exist  on  the 
Little  Danube. 

Grit  chambers  are  placed  upon  the  main  tributaries  of  the  principal  intercepting 
sewers.  These  grit  chambers  are  of  sufficient  size  to  reduce  the  velocity  sufficiently  to 
permit  sand  to  settle  out.  There  are  twelve  of  these  chambers  and  from  them  39,200 
cu.  yds.  of  grit  are  removed  each  year. 

The  large  volume  of  water  flowing  in  the  Danube  and  the  high  rate  of  flow,  aver- 


464         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

aging  about  6  ft.  per  second,  are  favorable  to  the  disposal  of  the  sewage  through  dilu- 
tion. The  water  within  the  city  is  without  visible  pollution.  It  is  said  that  after  the 
river  has  flowed  about  25  miles  beyond  the  city  there  is  no  trace  of  sewage  pollution. 

Paris 

Paris  affords  a  good  example  of  a  city  of  the  first  class  which  protects  its  water 
highways  by  a  comprehensive  plan  of  main  drainage.  Except  at  periods  of  storm,  no 
sewage  is  allowed  to  enter  the  river  Seine  within  the  city  limits.  In  consequence,  the 
Seine  within  the  city  limits  is  a  remarkably  clean  and  wholesome  looking  stream. 

How  difficult  the  accomplishment  of  this  thorough  protection  has  been  may  be 
understood  from  the  fact  that  the  river  winds  through  the  center  of  Paris,  is  a  navi- 
gable stream  and  supports  a  large  commerce. 


FIG.  16— PARIS 

Most  of  the  sewage  of  Paris  is  conveyed  to  Clichy,  where  it  is  passed  through  a  grit  chamber  and  screens  and 
pumped  to  extensive  farm  lands. 


MAIN  DRAINAGE  465 

The  sewers  of  Paris  are  intended  to  accommodate  the  sewage  of  houses  and  streets 
and  all  the  solid  matter  which  can  well  be  flushed  into  them  from  the  street  pavements. 
There  are  no  catch-basins,  in  consequence  of  which  sand,  paper,  fragments  of  wood 
and  much  other  coarse  debris  from  the  sidewalks  and  carriageways  enter  the  sewers 
and  must  there  be  dealt  with.  The  streets  are  washed  and  the  gutters  flushed  con- 
tinually. Unlike  the  usual  custom  of  flushing  sewers  by  means  of  suddenly  released 
reservoirs  of  clean  water,  the  sewers  of  Paris  are  flushed  with  their  own  sewage. 
This  is  accomplished  by  setting  a  movable  dam  in  the  sewers  which  causes  the  sewage 
to  accumulate  temporarily  until  there  is  a  considerable  force  behind  the  dam.  The 
dam  is  then  allowed  to  move  slowly  toward  the  outlet  of  the  sewer.  An  open  space 
between  the  dam  and  the  invert  provides  an  outlet  for  the  sewage,  which  flows  away 
with  a  scouring  action  sufficient  to  dislodge  whatever  accumulations  of  solids  may 
exist. 

The  siphons  which  carry  sewage  from  one  part  of  the  city  to  another  beneath  the 
river  are  kept  clean  by  passing  wooden  balls  through  them.  These  balls  are  slightly 
smaller  than  the  siphons  and  their  passage  causes  a  desirable  scouring  action.  The 
solid  matters  are  flushed  to  certain  parts  of  the  sewerage  system,  where  provision  in 
the  form  of  grit  chambers  exist  for  their  removal.  This  solid  material  is  removed  by 
means  of  grit  chambers,  emptied  into  cars  which  are  wheeled  to  the  river  bank  and 
there  discharged  into  barges. 

The  main  drainage  works  are  designed  to  focus  at  Clichy  on  the  Seine,  a  consider- 
able distance  beyond  the  city  limits.  Most  of  the  sewage  flows  to  this  point  by  gravity 
through  three  large  collectors.  Pumping  stations  in  some  parts  of  the  city  raise  a 
part  of  the  sewage  from  low-lying  areas  into  the  gravity  system.  Intercepting  sewers 
run  parallel  to  the  river  banks  within  the  city  limits  and  are  tributary  to  the  main 
sewers  which  lead  to  the  Clichy  station.  Some  of  the  sewage  in  the  northern  part  of 
the  city  is  carried  to  outfalls  into  the  Seine  at  St.  Denis  and  St.  Ouen,  points  consid- 
erably below  Clichy. 

The  sewage  of  Paris,  except  that  discharged  into  the  Seine  at  and  below  Clichy, 
is  utilized  upon  farm  land.  The  history  of  the  Paris  disposal  works  is  of  much  in- 
terest. Before  irrigation  was  adopted  various  other  methods  were  tried  for  the  dis- 
posal of  the  sewage.  A  scheme  for  taking  it  to  Havre  is  said  to  have  been  prepared, 
but  was  found  impracticable  by  reason  of  excessive  cost. 

It  was  at  first  supposed  that  the  sewage  could  be  sufficiently  relieved  of  its  impur- 
ities by  sedimentation  before  the  effluent  was  discharged  into  the  Seine.  Sedimenta- 
tion was  therefore  attempted  at  Clichy,  but  soon  proved  to  be  inadequate,  the  river 
becoming  black  and  offensive.  Deposits  of  sludge  occurred  which,  decomposing,  caused 


466  DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

bubbles  several  feet  in  diameter  to  rise  to  the  surface  and  burst,  leaving  large  quan- 
tities of  black  mud  to  return  slowly  to  the  bottom  or  become  diffused  through  the 
water.  It  is  estimated  that  there  were  107,000  cubic  yards  of  sludge  taken  from  the 
stream  each  year.  With  the  object  of  improving  the  efficacy  of  purification,  chemical 
precipitation  was  then  used,  sulphate  of  alumina  and  lime  being  the  reagents.  The 
result  was  greatly  to  increase  the  quantity  of  sludge  without  making  a  sufficient  im- 
provement in  the  effluent. 

In  1867  and  1868  irrigation  was  first  tried  on  a  small  experimental  plot  at  Olichy 
and  this  proved  so  successful  that  in  1869  the  city  offered  to  supply  sewage  gratis  to 
anyone  who  would  use  it  at  Gennevilliers. 

At  that  time  Gennevilliers,  which  is  situated  on  the  opposite  side  of  the  river  from 
Clichy,  was  a  small  and  obscure  place  devoid  of  agriculture.  Irrigation  proved  so 
successful  that  whereas  in  1870  there  were  55  acres  under  cultivation,  by  1875,  314 
acres  were  treated  with  sewage. 

The  Paris  plant  now  consists  of  four  large  areas,  the  oldest  at  Gennevilliers. 
Plants  of  more  recent  origin  are  situated  at  Acheres,  Pierrelaye  and  Carrieres  and 
Triel.  The  total  area  of  the  four  districts  amounts  to  about  13,597  acres,  about  one- 
third  of  which  is  owned  by  the  city.  At  Gennevilliers  the  land  is  privately  owned  and 
the  city  maintains  a  model  experimental  garden  for  the  cultivation  of  fruits  and 
flowers.  Among  the  crops  grown  are  peas,  tomatoes,  grass,  etc. ;  large  tracts  are  also 
used  for  pasturage.  The  cultivation  of  strawberries,  salad  crops  and  other  food  ex- 
posed to  sewage  and  eaten  raw  is  prohibited. 

About  185  million  gallons  of  sewage  per  day  are  produced  at  Paris.  Of  this 
amount  about  159  million  gallons  are  screened  at  Clichy,  the  screenings  amounting 
to  about  77,000  lbs.,  and  then  pumped  to  the  irrigation  fields.  The  distance  from 
Clichy  to  Carrieres-Triel  is  about  17.36  miles.  The  sewage  is  pumped  from  Clichy  to 
Colombes  against  a  head  of  16  feet.  At  Colombes  126,000,000  gallons  are  repumped 
with  a  lift  of  118  feet,  the  remainder  being  diverted  to  Gennevilliers.  At  Pierrelaye, 
a  part  of  this  is  repumped  with  a  lift  of  83  feet,  the  remaining  volume  continuing  by 
gravity  to  Acheres  and  Carrieres-Triel.   The  population  of  Paris  was  2,846,986  in  1911. 

The  sewage  is  delivered  to  the  fields  in  closed  conduits  and  distributed  in  ditches. 

Birmingham 

Birmingham,  with  a  population  of  850,000,  stands  on  high,  undulating  land  in  the 
center  of  England  and  is  situated  within  a  few  miles  of  the  headwaters  of  the  river 
Tame  which,  although  but  a  few  yards  wide,  receives  the  drainage  of  Birmingham  and 
a  number  of  other  municipalities  in  the  vicinity.    The  average  flow  of  the  river  is 


MAIN  DRAINAGE  467 

28,800,000  U.  S.  gallons  per  day,  which  is  less  than  the  quantity  of  sewage  which  must 
be  emptied  into  it. 

The  disposal  of  the  sewage  of  Birmingham  and  its  neighboring  towns  is  carried  on 
under  the  joint  management  of  a  drainage  district  which  covers  over  100  square  miles 
and  has  a  population  of  about  950,000.  The  managing  authority,  known  as  the  Bir- 
mingham, Tame  and  Rea  District  Drainage  Board,  was  created  in  1877.  The  disposal 
works  occupy  a  tract  of  about  3,000  acres  which  runs  for  six  miles  through  the  Tame 
valley  at  a  short  distance  from  Birmingham.  The  works  are  divided  into  parts,  some 
of  which  are  widely  separated.  Most  of  the  sewage  is  passed  through  grit  chambers, 
septic  tanks,  settling  basins,  sprinkling  filters  and  again  through  settling  basins.  The 
effluent  is  as  pure  as  the  river  water  into  which  it  is  discharged. 

The  process  of  sewage  treatment  is  remarkable  for  the  repeated  efforts  which  are 
made  to  remove  solid  matter  in  suspension  and  for  the  ingenuity  which  has  been  shown 
in  adapting  advanced  methods  of  sewage  purification  to  the  peculiarities  of  the  local 
situation. 

The  original  works  constructed  in  1895  comprised  chemical  precipitation  tanks 
and  about  80  acres  of  land  for  irrigation.  The  purification  effected  was  not  satisfac- 
tory and  numerous  experiments  were  made  to  improve  the  effectiveness  of  the  plant. 
It  is  said  that  454  patented  processes  were  experimented  with. 

At  one  time  the  Birmingham  disposal  works  consisted  of  the  largest  farms  in 
England  used  for  the  disposal  of  sewage.  The  farms  were  capable  of  dealing  with 
7,200  gallons  per  acre  per  day,  or  about  14,400,000  gallons  for  the  whole  area  capable 
of  receiving  sewage.  Notwithstanding  this,  the  land  was  frequently  called  upon  to 
deal  with  24,000,000  gallons  per  day,  with  the  result  that  the  effluent  deteriorated  and 
the  land  became  sodden.  The  cultivation  of  crops  was  then  given  up  and  the  fields 
were  alternately  flooded  and  drained  on  the  principle  of  intermittent  filtration.  This 
proved  a  failure  and  works  were  constructed  on  the  principle  of  biological  purification. 

Since  1911,  sprinkling  filters  have  dealt  with  the  dry-weather  flow  of  sewage  and  a 
large  amount  of  storm  water  as  well.  The  sewage  which  arrives  at  the  works  first 
passes  through  grit  chambers  through  which  the  sewage  flows  at  the  rate  of  3  inches 
per  second.  The  deposits  are  removed  by  dredging  and  carried  away  by  wagons  by  an 
industrial  railway  to  land  where  the  material  is  buried.  It  is  considered  better  not  to 
attempt  to  sell  or  utilize  this  solid  material  because  of  the  nuisance  likely  to  result 
and  its  small  manurial  value,  consisting  chiefly  of  about  2!/2  per  cent,  of  nitrogen  and 
about  I14  per  cent,  of  phosphoric  acid. 

On  passing  through  the  grit  chambers,  the  sewage  flows  through  septic  tanks 
where  solid  matter  is  deposited  and  fermentation  allowed  to  proceed.    The  septic 


468 


DATA  RELATING  TO  THE  PROTECTION  OP  THE  HARBOR 


tanks,  of  which  there  are  20,  are  divided  into  two  groups  called  primary  and  second- 
ary. The  sewage  flows  through  both  groups,  then  passes  over  a  distance  of  five  miles 
to  settling  basins  known  as  silt  tanks  and  thence  upon  sprinkling  filters.  These 
filters  consist  of  broken  stone  6  or  7  feet  deep  and  of  areas  between  1  and  3  acres  each, 
the  total  area  being  37  acres.  The  average  rate  of  filtration  is  about  900,000  U.  S. 
gallons  per  acre  per  day.  After  passing  through  the  bacteria  beds,  the  sewage  flows 
to  settling  tanks  where  solid  matters  in  suspension  are  removed  before  the  effluent  is 
allowed  to  enter  the  river  Tame. 

The  total  amount  of  suspended  matter  in  the  crude  sewage,  as  determined  from 
the  average  of  analyses  of  half-hourly  samples  taken  every  day  during  the  year  1908, 
amounted  to  522  parts  per  million.  During  that  year  the  total  quantity  of  sewage 
treated  was  about  14,400,000,000  gallons,  which  gives  24,300  tons  of  dry  matter  dis- 
posed of  in  that  year.  Of  this  total,  17  per  cent,  was  removed  in  the  grit  chambers; 
23  per  cent,  was  taken  out  in  the  septic  tanks  and  from  them  pumped  in  the  form  of 
sludge  to  fields,  where  it  was  allowed  to  settle  and  dry  sufficiently  to  be  ploughed  into 
the  soil.  The  silt  tanks  removed  18.1  per  cent.,  these  solids  being  pumped  to  the  sludge 
fields  and  dried  like  the  solid  matter  from  the  septic  tanks.  The  quantity  of  solids  re- 
moved in  the  separatory  tanks  which  received  the  sewage  after  it  had  left  the  sprink- 
ling filters  was  11.7  per  cent.  This  material  was  also  pumped  to  the  sludge  grounds. 
About  8.5  per  cent,  was  deposited  in  the  piping  system  and  was  flushed  out  and  pumped 
to  the  sludge  fields  and  9.7  per  cent,  was  deposited  on  land  where  some  of  the  sewage 
was  used  for  irrigation.  During  storms  8.2  per  cent,  passed  by  overflows  to  the  river. 
The  effluent  which  went  from  the  purification  works  to  the  river  contained  3.6  per  cent. 

Contrary  to  general  experience,  the  sludge  produced  at  Birmingham  has  been 
practically  without  odor,  a  fact  which  has  been  accounted  for  on  the  ground  that  a 
large  amount  of  trade  waste  is  present  containing  copper  and  iron,  which  interfere 
with  those  bacterial  growths  which  produce  foul-smelling  gases. 

Glasgow 

Prior  to  1894  the  sewage  of  Glasgow  was  discharged  without  purification  into 
the  river  Clyde.  The  evils  which  resulted  from  this  practice  were  comparable  with 
those  which  once  obtained  on  the  Thames  at  London. 

The  territory  included  in  the  Glasgow  main  drainage  project  extends  along  both 
sides  of  the  river  for  about  15  miles,  the  total  area  being  4iy2  square  miles.  It  is 
expected  that  the  ultimate  development  will  yield  a  total  volume  of  sewage,  including 
rainfall,  of  300  million  gallons  per  day.  The  drainage  area  is  divided  into  three  parts, 
each  tributary  to  a  central  collecting  station  where  the  precipitation  works  have  been 
constructed.   The  population  was  735,906  in  1901. 


MAIN  DRAINAGE  469 

The  first  section  drains  the  combined  sewage  of  about  11  square  miles,  one-half  of 
which  is  within  the  city  limits,  to  the  works  situated  at  Dalmarnock.  These  works 
have  been  in  operation  since  May,  1894,  and  deal  with  about  24  million  gallons  per  day. 

The  second  section  comprises  that  part  of  the  municipal  area  of  Glasgow  which  lies 
on  the  north  side  of  the  river  westward  of  the  first  section  and  some  outside  territory, 
tbe  whole  area  being  about  15  square  miles.  These  disposal  works  are  at  Dalmuir  on 
the  river  banks  about  8  miles  below  Glasgow.  The  daily  volume  of  sewage  to  be 
treated  ultimately  is  58.6  million  gallons. 


FIG.  17— GLASGOW 

The  sewage  is  collected  to  three  central  points,  where  it  is  passed  through  chemical  precipitation  works  and  the 
effluent  discharged  into  the  river  Clyde.  At  two  of  the  works,  the  sludge  is  put  on  board  of  tank  steamers  which 
carry  it  to  sea.   At  the  other  works  the  sludge  is  converted  into  fertilizer. 


The  third  section  includes  the  whole  municipal  area  of  Glasgow  which  lies  on  the 
south  bank  of  the  river  and  some  outlying  territory,  the  total  area  being  15!/2  square 
miles.  These  disposal  works  are  at  Shieldhall,  4y2  miles  below  Glasgow.  The  daily 
volume  of  sewage  ultimately  provided  for  is  58.6  million  gallons. 

The  sewers  tributary  to  the  Glasgow  works,  like  most  sewers  of  Great  Britain,  were 
designed  to  carry  both  domestic  and  industrial  sewage  and  a  certain  proportion  of  the 
rainfall.  The  allowance  for  rainfall  is  one-quarter  of  an  inch  in  24  hours.  Rain  water, 
in  excess  of  that  allowed  for,  passes  through  regulating  valves  placed  between  the 


470         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

street  drains  and  the  main  sewers  and  so  flows  to  the  river.  Tide  gates,  consisting  of 
balanced  flaps,  are  intended  to  prevent  the  river  water  from  entering  the  sewers  dur- 
ing ordinary  conditions  of  weather.  The  action  of  these  automatic  tide  gates  is  said 
to  be  satisfactory. 

On  arriving  at  Dalmuir  the  sewage  is  passed  through  a  screen  and  flows  thence 
to  a  grit  chamber  which  is  cleaned  by  a  bucket  dredger  which  travels  to  and  fro  on 
tracks  over  the  top  of  the  basin.  The  precipitating  chemicals  are  then  added,  and  the 
sewage  flows  into  one  or  other  of  eight  precipitation  tanks,  each  750  feet  long  by  about 
80  feet  broad,  situated  on  the  river  bank  at  a  level  of  about  4^/2  feet  above  high  tide. 

The  chemicals  employed  are  persulphate  of  iron  and  lime  water.  A  saturated  sol- 
ution of  lime  water  is  used  as  a  precipitant.  This  is  said  to  be  an  advantage  over  the 
custom  of  using  milk  of  lime,  which  introduces  a  considerable  amount  of  suspended 
matter  into  the  precipitation  basins.  The  iron  is  purchased  in  the  form  of  ferrous 
sulphate.  It  is  dissolved  in  tanks  at  a  temperature  of  100  degrees  Fahr.,  protosulphate 
of  iron  being  then  produced.  The  liquor  from  the  tanks  is  raised  by  a  pump  to  an 
overhead  storage  tank  from  which  it  is  drawn  from  time  to  time  into  oxidizer  drums. 
These  drums  are  made  of  wood,  12  feet  long  and  12  feet  in  diameter.  They  receive  a 
charge  of  protosulphate  of  iron  and  a  small  quantity  of  nitrate  of  soda.  The  drums 
are  then  closed  and  paddles  are  set  in  motion  which  agitate  the  contents.  At  the  end 
of  three-quarters  of  an  hour  or  so,  the  liquor,  now  persulphate  of  iron,  is  run  off  in 
vats  below  the  drums  and  is  ready  for  use. 

During  the  year  ending  May  31,  1913,  the  sludge  steamer  Dalmuir  made  271  trips 
at  a  cost  of  $0.05  per  ton  of  sludge.  The  sludge  contained  86.16  per  cent,  of  moisture. 
There  were  produced  22.9  tons  of  crude  sludge  per  million  gallons  of  sewage.  The 
quantity  of  material  removed  from  the  sewage  by  screens  and  grit  chambers  was  6  cwt. 
per  million  gallons.  At  Dalmarnock  the  sludge  produced  was  44.4  tons  per  million 
gallons.  The  average  moisture  was  98  per  cent.  There  were  treated  at  the  three 
works  117.9  million  gallons  of  sewage  per  day. 

The  effluent  from  the  tanks  flows  into  a  wide  channel  and,  after  passing  over  a 
gauge  weir,  is  discharged  into  the  river  by  means  of  pipes  which  are  protected  from 
the  back  flow  of  the  tide  by  balanced  tide  flaps. 

To  remove  the  sludge,  each  precipitation  tank  is  emptied  in  succession,  the  sludge 
being  drained  into  a  sludge  well  from  which  it  is  pumped  into  an  overhead  storage 
tank.  After  a  brief  period  of  settlement,  the  sludge  is  allowed  to  flow  into  a  steamer 
with  a  capacity  of  about  1,200  tons  of  sludge.  The  steamer  carries  the  sludge  to  a 
point  about  45  miles  from  Dalmuir  in  the  Firth  of  Clyde,  where  the  sludge  is  dis- 
charged in  about  10  minutes  into  water  60  to  90  fathoms  deep. 


MAIN  DRAINAGE  471 

The  method  of  sludge  disposal  at  Shieldhall  is  practically  the  same  as  at  Dalmuir. 
The  works  at  Dalmarnock  treat  the  sewage  in  the  same  way  as  it  is  treated  at  Dal- 
muir and  Shieldhall,  but  the  sludge  is  pressed  for  the  reason  that  the  river  Clyde  is 
not  of  sufficient  depth  at  Dalmarnock  to  accommodate  a  sludge  steamer  of  the  requisite 
size. 

The  sewage  at  Dalmarnock  consists  largely  of  industrial  refuse,  the  suspended 
matter  varying  from  285  to  14,240  parts  per  million.  It  is  claimed  that  the  treatment 
eliminates  the  suspended  matter  and  effects  a  chemical  purification  of  50  per  cent,  cal- 
culated on  the  albuminoid  basis.  After  treatment  the  sewage  is  discharged  into  the 
Clyde  which,  at  Dalmarnock,  has  a  volume  50  times  greater  than  the  average  volume 
of  sewage  discharged. 

Further  down  the  river  at  Shieldhall  and  Dalmuir,  the  115  million  gallons  of  sew- 
age which  is  discharged  is  diluted  with  about  3,000  million  gallons  of  water.  It  is  as- 
sumed that  the  natural  agencies  in  the  river  effect  the  final  purification  of  the  effluent, 
more  especially  in  the  lower  regions. 

The  cost  of  the  Glasgow  main  drainage  undertaking  exceeds  |10,000,000.  It  is 
said  that  the  increased  rate  of  taxation  due  to  this  expenditure  has  raised  no  objection 
on  the  part  of  the  public.  The  undertaking  has  removed  from  the  Clyde  the  solid  mat- 
ters of  the  sewage  of  Glasgow  and  adjacent  boroughs  and  has  restored  what  has  been 
termed  a  dead  river  at  certain  period  of  the  year  to  a  live  and  satisfactory  condition. 

Leeds 

The  sewage  of  Leeds  contains  a  large  amount  of  suspended  solids,  averaging  in 
the  year  ending  March  31,  1913,  604  parts  per  million.  The  soluble  solids  amounted 
to  1,010  parts  and  the  albuminoid  ammonia  to  7.69  parts.  In  the  year  mentioned,  the 
suspended  solids  in  the  effluent  from  the  works  which  is  discharged  into  the  River 
Aire  were  44  parts  per  million,  the  soluble  solids  1,001  parts  and  the  albuminoid  am- 
monia 4.8  parts. 

The  main  drainage  system  was  begun  in  1848  and  the  city  has  been  in  legal  diffi- 
culty from  the  pollution  of  the  Aire  since  1870.  Experimental  methods  of  disposal 
were  early  tried  and,  in  1874,  settling  tanks  and  chemical  precipitation  were  under- 
taken. The  method  employed  in  1913  was  chemical  precipitation,  but  this  method  did 
not  produce  an  effluent  which  was  considered  satisfactory. 

The  works  for  Leeds  are  situated  at  Knostrop  on  the  River  Aire  near  the  south- 
east boundary  of  the  city  at  a  distance  of  2  miles  from  the  Leeds  town  hall.  The  pop- 
ulation which  drained  to  Knostrop  in  1912  was  435,845. 

One  of  the  first  things  done  by  the  West  Riding  of  Yorkshire  Rivers  Board  when 


472  DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


FIG.  18— LEEDS 

The  sewage  is  conveyed  to  a  central  point  beyond  the  city  limits,  where  it  is  treated  by  chemical  precipitation 
and  the  sludge  dried  by  filter  presses.  A  large  area  of  land  has  been  procured  in  order  to  provide  for  a  more  effi- 
cient process  of  disposal  before  the  sewage  is  discharged  into  the  river  Aire. 


it  came  into  existence  in  1893  was  to  bring  pressure  to  bear  upon  the  Corporation  of 
Leeds  to  deal  with  its  sewage  in  an  adequate  manner.  Soon  after  this,  the  works  were 
increased  in  capacity  and  experiments  were  undertaken  on  biological  treatment.  The 
land  available  for  the  works  was  inadequate  for  material  improvements  and  it  was  not 
until  1908  that  600  acres  were  purchased  in  the  vicinity  of  Knostrop  and  the  city  is 
now  going  forward  with  the  construction  of  needed  improvements  and  extensions. 

The  experiments  made  by  Leeds  between  1898  and  1905  left  little  to  be  desired  for 
thoroughness  and  comprehensiveness.  As  a  result,  it  was  decided  that  the  process  to 
be  employed  should  be  chemical  precipitation  followed  by  treatment  with  sprinkling 
filters,  with  possible  subsequent  settlement  in  humus  tanks.  This  process  seemed 
likely  to  most  completely  satisfy  the  local  requirements  of  site,  quality  of  the  sewage 
and  the  demands  of  the  Local  Government  Board  and  West  Riding  of  Yorkshire 
Rivers  Board  with  respect  to  the  quality  of  the  effluent.    This  process  also  possessed 


MAIN  DRAINAGE  473 

the  following  advantages:  Small  area  required  for  settling  tanks;  the  sludge  would  be 
easy  to  press  with  a  small  addition  of  lime ;  the  danger  of  nuisance  from  smell  would 
be  reduced  to  a  minimum  because  the  process  being  rapid,  putrefactive  changes  would 
not  set  in;  the  effluent  from  the  precipitation  tanks  could  be  oxidized  on  beds  6  feet 
deep,  whereas  the  beds  would  have  to  be  9  feet  deep  if  they  were  to  treat  a  settled  or 
septic  effluent  separately ;  no  costly  process  would  be  needed  for  the  removal  of  solids 
from  the  effluent  or  the  filter  bed;  the  filters  would  be  of  a  permanent  character,  if 
properly  constructed ;  during  heavy  rains  five  times  the  dry- weather  flow  could  be  suc- 
cessfully treated. 

The  new  works  provide  for  the  sewage  of  650,000  persons  with  a  dry-weather  flow 
of  48  U.  S.  gallons  per  capita  per  day,  or  a  total  of  31,200,000  gallons.  During  storms 
the  works  will  care  for  a  flow  of  4.6  times  this  amount,  or  144,000,000  gallons  per  day. 
Of  this,  the  first  72,000,000  gallons  receives  full  treatment  and  the  remaining  72,000,000 
gallons  partial  treatment  in  tanks  as  storm  water. 

The  sewage  first  passes  through  coarse  screens  and  grit  chambers  to  remove  the 
large  solid  particles.  It  is  then  pumped  to  the  precipitation  tanks  and  mixed  with 
lime  and,  if  necessary,  other  chemicals  to  eliminate  the  sludge.  The  effluent  to  the 
extent  of  2.3  times  the  dry-weather  flow  is  thence  pumped  to  primary  sprinkling 
filters  through  which  it  is  passed  by  gravity  to  humus  tanks  or,  if  necessary,  second- 
ary sprinkling  filters  and  so  to  the  river.  The  second  2.3  times  the  dry-weather  flow  of 
effluent  flows  by  gravity  to  the  river  after  undergoing  settlement  in  tanks  in  conjunc- 
tion with  treatment  by  chemical  precipitation.  The  sludge  resulting  from  the  precipi- 
tation receives  a  dose  of  lime  and  is  then  pressed.  The  pressed  cake  is  carried  by  rail- 
way to  a  site  of  200  acres  of  low-lying  land,  where  it  is  deposited  and  covered  with  a 
thin  layer  of  surface  soil.  In  1913,  10,000  tons  of  sludge  cake  was  consigned  to 
farmers. 

The  sprinkling  filters  cover  an  area  of  12  acres  with  a  depth  of  6  feet.  In  the 
year  1913  the  quantity  of  sewage  dealt  with  at  the  Knostrop  works  averaged  22,100,000 
gallons  or  50.7  gallons  per  capita  per  day. 

London 

Imperfect  methods  of  drainage  resulted  from  the  introduction  of  house  drainage 
into  the  sewers  after  the  year  1817.  A  commission  known  as  the  Metropolitan  Com- 
mission of  Sewers  was  created  to  improve  the  conditions,  and  this  board  superseded 
eight  distinct  and  independent  bodies  which  had  formerly  exercised  authority  over  the 
London  sewers.  Within  6  years  30,000  cesspools  were  abolished,  the  houses  being  con- 
nected directly  with  the  sewers. 


474         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

This  improvement  to  the  drainage  of  the  city  was  accompanied  by  decided  injury 
to  the  river  Thames  and  the  public  press  began  to  agitate  for  a  remedy.  After  various 
commissions  had  been  appointed  between  1849  and  1854,  the  Metropolitan  Board  of 
Works  was  created  in  1856.  The  main  drainage  works  which  now  exist  are  due  to  the 
initiative  of  that  body  which  was  especially  created  to  put  a  stop  to  the  pollution  of 
the  Thames.  In  1899,  the  London  County  Council  took  over  the  work  of  main  drainage 
and  has  since  had  authority  over  it. 

In  1856  Sir  Joseph  Bazalgette,  Chief  Engineer  of  the  Metropolitan  Board  of 
Works,  reported  as  to  the  plans  necessary  to  completely  intercept  the  sewage  of  Lon- 
don and  discharge  it  into  the  river  below  the  Metropolis  instead  of  directly  into  the 
river  at  about  the  level  of  low  tide.  As  the  tide  rose,  the  sewage  was  ponded  back  into 
the  sewers.  Heavier  ingredients  were  deposited  and  the  liquids  remained  stagnant  for 
long  periods.  The  sewage  was  carried  back  and  forth  by  the  rising  tide,  progress  toward 


Note:-The  darker  areas  represent  the  denser  populations 

LEGEND 


The  sewage  is  carried  to  Barking  and  Crossness,  beyond  the  city  limits,  where  it  is  treated  by  chemical  precipi- 
tation in  covered  tanks  and  the  effluent  discharged  into  the  Thames.    The  sludge  is  taken  to  sea  in  tank  steamers- 


MAIN  DRAINAGE  475 

the  sea  being  very  slow.  The  condition  of  the  Thames  was  exceedingly  offensive,  re- 
ceiving, as  it  did,  the  sewage  of  nearly  3,000,000  people  in  the  midst  of  the  city. 

According  to  Budd,  a  prominent  physician  of  the  time:  "Stench  so  foul,  we  may 
well  believe,  had  never  before  ascended  to  pollute  this  lower  air.  For  many  weeks  the 
atmosphere  of  Parliamentary  committee  rooms  was  only  rendered  barely  tolerable  by 
the  suspension  before  every  window  of  blinds  saturated  with  chloride  of  lime  and  by 
the  lavish  use  of  this  and  other  disinfectants.  More  than  once,  in  spite  of  similar  pre- 
cautions, the  law  courts  were  suddenly  broken  up  by  an  insupportable  invasion  of  the 
noxious  vapor.  The  river  steamers  lost  their  accustomed  traffic,  and  travelers,  pressed 
for  time,  often  made  a  circuit  of  many  miles  rather  than  cross  one  of  the  city  bridges." 

The  main  feature  of  the  scheme  devised  by  the  Metropolitan  Board  of  Works  was 
carried  out  between  1856  and  1874.  It  consisted  of  the  construction  of  intercepting 
sewers  with  which  the  main  sewers,  which  previously  delivered  sewage  into  the  river, 
were  connected.  The  intercepting  sewers  were  carried  to  Barking  on  the  north  side  of 
the  river,  11  miles  below  London  Bridge  and  to  Crossness  on  the  south  side  of  the  river, 
13  miles  below  London  Bridge.  The  objects  to  be  attained  were  to  keep  the  sewage  out 
of  the  river  within  the  city  limits,  to  substitute  a  constant  instead  of  intermittent  flow 
in  the  sewers,  to  abolish  the  tide-locked  sewers  with  their  constant  accumulation  of 
deposited  matters  and  to  substitute  deeper  and  better  sewers  with  improved  gradients 
and  outfalls. 

Eventually  three  classes  of  sewers  came  under  the  control  of  the  Metropolitan 
Board:  Main  sewers  running  at  right  angles  to  the  river;  intercepting  sewers  parallel 
to  the  river,  and  outfall  sewers  running  parallel  to  the  river  and  beyond  the  intercept- 
ing sewers.  These  main  drainage  works  received  their  sewage  from  local  sewerage 
systems  under  the  control  of  the  vestries  and  district  boards  and  now  under  the 
municipal  borough  councils  of  the  many  cities  of  which  London  is  composed. 

The  system  was  designed  for  a  population  of  3,450,000  persons  and  129,600,000 
U.  S.  gallons  of  dry-weather  flow  collected  in  combined  sewer  systems.  The  amount 
of  rainfall  admitted  was  rather  more  than  2y2  times  the  dry-weather  flow.  The  old 
sewers  were  used  for  storm  overfloAvs. 

In  course  of  time  the  population  increased  beyond  the  provisions  already  made 
and  additional  intercepting  and  storm  relief  sewers  had  to  be  constructed.  The  average 
daily  flow  of  sewage  discharged  at  both  outfalls  for  1911-12  was  386,500,000  gallons  per 
day. 

The  total  discharging  capacity  of  the  Barking  and  Crossness  works  is  about 
859,000,000  and  943,000,000  gallons  per  24  hours,  respectively.  The  population  drain- 
ing into  the  Council's  sewers  in  1911  was  5,336,100. 


476  DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

The  net  capital  expenditure  of  the  Metropolitan  Board  of  Works  and  the  London 
County  Council  up  to  March  31,  1912,  was  $60,971,770.  The  total  length  of  main  in- 
tercepting and  storm  sewers  is  about  370  miles. 

The  sewage  which  was  carried  to  Barking  and  Crossness  was  at  first  discharged 
from  reservoirs  on  the  outgoing  currents.  A  marked  improvement  was  visible  in  the 
Thames  after  a  time.  Ten  years  after  the  opening  of  the  works,  it  became  apparent 
that  the  river  was  being  overtaxed  and  the  experience  of  years  before  in  a  crowded 
section  of  the  city,  when  the  sewage  was  carried  back  and  forth  and  produced  a  nui- 
sance, was,  in  a  measure,  repeated  near  the  works. 

In  1869,  1878  and  1882  inquiries  were  held  and  it  was  stated  that  sewage  ought 
not  to  be  discharged  in  a  crude  state  in  any  part  of  the  Thames.  As  a  result  of  many 
experiments,  it  was  decided  to  reconstruct  the  works  at  Barking  and  Crossness  so  as 
to  treat  the  sewage  on  the  principle  of  chemical  precipitation.  It  was  found  that 
56.96  parts  per  million  of  lime  and  14.24  parts  per  million  of  protosulphate  of  iron 
were  sufficient  practically  to  remove  the  whole  of  the  suspended  matter  and  the  grosser 
part  of  the  offensive  odors.  It  was  expected  that  the  liquid  part  of  the  sewage  would 
be  assimilated  by  the  river  water.  This  method  of  treatment  was  put  into  effect  at 
Barking  in  1889  and  at  Crossness  in  1891. 

The  sewage  receives  the  chemicals  as  it  enters  the  works  and  then  flows  through 
underground  settling  basins,  of  which  there  are  13  at  Barking,  varying  in  length  from 
860  to  1,200  feet  with  a  width  of  30  feet  and  a  holding  capacity  of  24,000,000  gallons. 
The  effluent  flows  from  the  basins  into  the  river.  At  intervals  of  about  60  hours,  each 
basin  is  shut  off,  the  sewage  withdrawn  and  the  heavier  suspended  matters,  called 
sludge,  are  pushed  by  hand  labor  to  a  sump  and  then  passed  through  screens  to  storage 
tanks. 

The  storage  tanks  discharge  the  sludge,  containing  about  92  per  cent,  of  moisture, 
to  vessels  which  carry  it  to  sea.  The  sludge  vessels  have  a  capacity  of  1,000  tons  each. 
They  carry  their  cargo  57  miles  below  Barking  to  the  mouth  of  the  Thames  estuary, 
where  discharge  takes  place  over  a  length  of  about  8  or  10  miles.  Approximately  8,200 
pounds  of  sludge  were  sent  to  sea  daily  in  1911.  The  vessels  are  of  modern  construc- 
tion with  twin  screws  and  discharge  their  cargoes  by  gravity. 

At  Barking  and  Crossness,  where  the  liquid  part  of  London's  sewage  is  discharged, 
the  Thames  is  over  2,000  feet  wide  and  has  a  range  of  tide  of  18  feet.  There  is  a  flow 
of  tidal  water  of  2,000  million  cubic  feet  a  day  and,  in  addition,  a  discharge  of  100,000 
cubic  feet  of  upland  water.  The  effluents  do  not  produce  unsightly  conditions.  The 
river  water  is  somewhat  turbid,  often  more  so  than  the  sewage  which  is  discharged 
into  it.    The  average  percentage  of  saturation  of  dissolved  oxygen  in  1912  was  20.8 


MAIN  DRAINAGE  477 

at  high  water  and  35.5  at  low  water  near  the  Crossness  works.  During  warm  weather 
some  odor  is  produced  for  10  or  12  miles  above  and  below  the  outfalls,  but  this  is  not 
noticeable  much  beyond  the  river  banks. 

Anticipating  that  it  may  be  necessary  to  produce  an  effluent  of  greater  purity  than 
is  possible  by  chemical  precipitation,  the  London  County  Council  has  recently  ob- 
tained an  area  of  about  750  acres  in  the  vicinity  of  Barking  and  Crossness,  where  im- 
proved methods  of  sewage  disposal  can  be  employed. 

Salfobd 

The  Salford  works  occupy  about  20  acres  of  land  adjoining  the  Manchester  Ship 
Canal  and  otherwise  surrounded  by  a  built-up  section  of  the  city.  The  works  consist 
of  chemical  precipitation  tanks,  roughing  filters,  sprinkling  filters  and  sludge  tanks. 
The  sludge  is  carrier  to  sea  by  a  vessel,  the  distance  traveled  being  128  miles  in  the 
round  trip. 

Most  of  the  sewage  reaches  the  works  from  the  main  intercepting  sewer,  which  is 
laid  near  the  river  Irwell,  crossing  the  river  at  three  points.  About  one-third  of  the 
sewage  which  is  brought  in  the  main  interceptor  flows  through  the  works  by  gravity. 
The  dry-weather  flow  is  about  13,200,000  U.  S.  gallons,  of  which  about  9,000,000  flow 
between  9  A.  M.  and  9  P.  M.  The  average  flow  is  between  15,600,000  and  19,200,000  gal- 
lons, and  the  greatest  flow  provided  for  is  38,400,000  gallons.  As  in  most  English  towns, 
the  sewers  take  storm  water  as  well  as  house  sewage  and  industrial  drainage.  Of  the 
13,200,000  gallons  of  dry-weather  flow,  about  7,920,000  gallons  is  domestic  sewage,  as 
estimated  from  the  drinking  water  supply ;  about  3,600,000  is  liquid  trade  waste  and 
the  remaining  1,680,000  is  ground  water.  The  ultimate  flow  provided  for  is  161  gal- 
lons per  capita  per  day,  reckoned  on  the  basis  of  a  population  of  about  231,000  in  1911. 

At  the  disposal  works,  the  main  intercepting  sewer  has  a  sump  sunk  2  feet  below 
its  invert  from  which  a  chain  bucket  dredger  daily  transfers  by  steam  power  such 
deposits  as  occur  into  cars  which  convey  them  to  sludge  tanks  and  so  to  sea  by  steamer. 

There  are  three  screening  chambers  controlled  by  valves.  The  screens  are  3  feet 
wide,  13  feet  high  and  have  bars  %  of  an  inch  apart.  From  these  screens  the  sewage 
is  pumped  between  20  and  30  feet  to  a  mixing  chamber  from  which  it  flows  by  gravity 
throughout  the  rest  of  the  works.  The  sewage  flows  through  the  mixing  chamber 
to  a  weir  below  which  dissolved  salts  of  iron  are  added,  and  about  20  yards  further 
milk  of  lime  is  applied. 

Settling  tanks,  five  in  number,  are  situated  on  each  side  of  a  central  channel  10 
feet  wide,  4  feet  deep  and  550  feet  long  through  which  the  sewage  flows  after  receiv- 
ing the  chemicals.    It  is  possible  to  conduct  the  flow  through  all  of  the  10  tanks  in 


478         DATA  RELATING  TO  THE  PROTECTION  OP  THE  HARBOR 


FIG.  20— SALFORD 

The  sewage  is  treated  by  chemical  precipitation,  roughing  niters  and  sprinkling  niters.  The  sludge  is  shipped 
to  sea  in  tank  steamers. 


series  or  through  groups  of  5,  3  or  2  tanks.  Sewage  can  also  be  carried  through  single 
tanks  operated  in  parallel.  Any  tank  can  be  shut  off,  emptied  and  cleaned  when  re- 
quired. The  capacity  of  the  10  tanks  is  6,000,000  gallons.  Each  is  about  150  feet 
long,  82  feet  wide  and  from  7  to  10  feet  deep.  The  sludge  which  is  deposited  here  is 
carried  away  to  sludge  tanks  which  deliver  it  to  the  ship  to  be  carried  to  sea. 

The  sewage  is  withdrawn  from  above  the  sludge  and  led  to  the  roughing  filters,  of 
which  there  are  six.  Each  roughing  filter  has  a  row  of  inlet  holes  supplied  from  a 
chamber  in  the  outlet  channel.   The  floor  is  of  perforated  tile  set  on  short  legs.  The 


MAIN  DRAINAGE  479 

filtered  material  consists  of  3  feet  of  gravel  between  one-sixteenth  and  five-sixteenths 
inch  in  diameter.  Their  object  is  to  remove  matter  in  suspension  and  especially  col- 
loidal matter  which  has  escaped  the  precipitation  tanks.  About  three  tons,  reckoned 
as  dried  material,  are  removed  daily.  The  roughing  filters  are  washed  by  an  upward 
or  reverse  current,  the  washing  process  being  facilitated  by  a  system  of  air  pipes  fitted 
near  the  floor.  The  air  is  blown  through  these  pipes  at  a  pressure  of  2  pounds  per 
square  inch,  escaping  by  means  of  4,800  holes  of  one-eighth  inch  diameter  and  14 
inches  apart,  thereby  distributing  the  gravel  and  facilitating  the  upward  flow  of 
wash  water. 

The  sewage  passes  to  the  sprinkling  filters  by  means  of  30-inch  pipes  with  suitable 
branches  and  control  valves  and  is  distributed  by  means  of  spray  jets,  each  serving 
an  area  10  feet  by  5  feet  2  inches. 

The  filter  floors  are  concrete  with  culverts  at  62-foot  intervals  for  conveying  the  fil- 
tered sewage  to  the  final  outfall  sewer,  which  is  4  feet  in  diameter.  The  earlier  beds 
have  ventilating  manholes  at  each  end  and  the  beds  recently  constructed  are  provided 
with  vent  shafts  and  open  sides  to  allow  free  airway. 

The  filtering  material  is  crushed  cinders  and  clinkers,  the  particles  ranging  in 
size  from  about  three-sixteenths  to  three-quarters  of  an  inch  in  diameter  in  the  earlier 
beds  and  from  one-quarter  to  one  and  one-quarter  inches  in  diameter  in  the  later  beds, 
with  some  coarse  material  at  the  bottom.  All  the  sprinkling  filters  have  recently  been 
emptied,  the  media  washed  and  new  media  used  as  follows:  12  inches  of  material  3  to 
5  inches  in  diameter,  7  feet  of  material  from  %  to  iy2  inches,  then  another  12  inches 
of  the  existing  washed  material  not  less  in  size  than  half  an  inch,  thus  making  the 
depth  of  the  bed  9  feet. 

The  spray  jets  work  under  an  available  head  of  about  8  feet  and  these  deliver  at 
the  rate  of  62  gallons  per  square  yard  per  hour,  or  1,440  gallons  per  twenty-four 
hours,  if  running  continually.  There  are  39,000  square  yards  of  bed.  It  has  been 
found  desirable  to  run  each  bed  for  two  hours  and  then  rest  it  for  10  hours,  accord- 
ing to  the  quantity  of  sewage  to  be  dealt  with.  The  effluent  from  the  sprinkling  fil- 
ters discharges  into  the  Manchester  Ship  Canal,  formerly  the  river  Irwell. 

The  sludge  from  the  precipitation  tanks  flows  to  sludge  tanks  where  men  with 
push  bars  sweep  it  to  an  outlet  leading  to  the  sludge  tanks,  wading  in  the  sludge  with 
waterproof  thigh  boots.  There  are  two  sludge  tanks,  saucer  shaped,  100  feet  in  diam- 
eter, 9  feet  deep,  holding  about  3,000  tons  of  sludge.  The  sludge  is  pumped  by  double- 
acting  piston  pumps  with  a  capacity  of  200  tons  per  hour  to  a  sludge  steamer  lying  at 
a  neighboring  wharf.  The  steamer  is  130  feet  long,  13  feet  beam,  11  feet  draft  loaded 
and  carries  600  tons  of  sludge.   The  distance  traveled  to  the  dumping  grounds,  near 


480  DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

the  northwest  lightship  off  Liverpool,  is  64  miles.    Four  or  five  trips  are  made  each 

week. 

The  management  of  the  works  has  under  consideration  the  questions  of  extending 
the  two  filter  beds,  the  sprinkling  filters  and  the  provision  of  grit  chambers  and  humus 
tanks. 

Sheffield 

The  sewage  of  Sheffield  was  discharged,  untreated,  into  the  rivers  and  water 
courses  in  the  vicinity  of  the  city  until  1886,  at  which  time  main  drainage  works  were 
completed  and  a  sewage  disposal  plant  was  built  to  work  on  the  principle  of  precipi- 
tation by  means  of  lime  and  aeration  over  weirs,  followed  by  continuous  filtration 
through  coke.  A  few  years  ago,  it  was  decided  to  reconstruct  the  works  so  as  to 
operate  in  accordance  with  the  principles  of  sedimentation  and  subsequent  oxidation 
in  contact  beds. 

The  city,  which  is  one  of  the  most  important  municipal  centers  in  England  has  a 
population  of  about  half  a  million.  The  natural  elevations  of  the  land  are  such  as  to 
make  it  unnecessary  to  pump  the  sewage  at  any  point  through  the  total  length  of  400 
miles  of  sewers  or  to  the  outfall,  which  is  about  8  miles  from  the  farthest  point  at 
which  any  of  the  sewage  enters  the  sewerage  system. 

At  the  time  the  reconstruction  of  the  disposal  works  was  begun,  the  plant 
covered  about  23  acres.  There  were  30  precipitation  tanks,  each  with  a  capacity  of 
60,000  U.  S.  gallons.  The  estimated  average  daily  flow  for  which  the  works  were  de- 
signed was  12,000,000  gallons,  but  for  some  years  a  flow  of  approximately  20,400,000 
gallons  and  a  maximum  of  26,400,000  gallons  was  treated. 

The  sludge  produced  amounted  to  between  800  and  1,000  tons  a  week,  as  meas- 
ured in  condition  for  removal.  The  sludge  was  carried  away  from  the  works  by  rail 
and  pumped  upon  land,  about  22  acres  of  country  land  being  reserved  for  the  purpose. 
In  all  about  1,000,000  tons  of  sludge  have  been  dealt  with  in  this  manner. 

The  foregoing  method  of  sewage  disposal  was  not  satisfactory  to  the  Local  Gov- 
ernment Board  and  West  Riding  of  Yorkshire  Rivers  Board  and  it  was  in  conse- 
quence of  this  fact  that  Sheffield  was  compelled  to  adopt  a  more  efficient  process. 
Precipitation  with  lime  came  to  be  regarded  as  having  no  effect  upon  the  dissolved 
impurities  and  was  therefore  incapable  of  preventing  decomposition  of  the  effluent 
when  mingled  with  the  river  water. 

Various  ways  of  dealing  with  the  sewage  were  considered,  among  them  the  con- 
struction of  an  outfall  from  Sheffield  to  the  east  coast  of  England  by  means  of  which 
the  sewage  could  be  discharged  into  the  sea.    Biological  experiments  were  made  of 


MAIN  DRAINAGE  481 

various  methods  of  purifying  the  sewage,  with  the  result  that  settlement,  followed  by 
treatment  in  contact  beds,  was  eventually  decided  upon,  after  a  full  consideration  of 
the  results  of  the  experiments,  the  difficulties  of  site,  the  trade  wastes  peculiar  to  the 
city  and  other  local  circumstances. 

The  settling  tanks  were  to  operate  upon  the  contact  principle  with  the  understand- 
ing that  if  single  contact  did  not  accomplish  the  oxidizing  effects  wanted,  second  con- 
tact beds  could  be  added.  The  reconstruction  of  the  works  represents  an  expenditure 
of  about  §2,000,000  and  has  had  to  be  carried  on  without  interference  with  the  old 
works. 

The  new  works  are  capable  of  dealing  with  a  maximum  flow  of  77,400,000  gallons 
per  24  hours.  This  increase  above  the  12,000,000  gallons'  capacity  of  the  old  works  is 
due  partly  to  the  increase  in  population  of  Sheffield,  but  chiefly  to  the  fact  that  the 
Local  Government  now  requires  six  times  the  dry-weather  flow  to  be  treated  during 
periods  of  storm.  The  average  dry-weather  flow  is  expected  to  be  about  14,400,000 
gallons  per  day. 

The  whole  of  the  sewage  will  pass  through  catch-basins,  grit  chambers  and  settling 
tanks  and  the  flow,  up  to  38,640,000  gallons,  will  be  treated  on  contact  beds. 

The  grit  chambers  are  constructed  in  the  form  of  double  hoppers,  between  each  of 
which  a  screening  arrangement  extends  the  whole  length  of  the  chamber.  The  screens 
are  cleaned  by  hand  rakes.  This  method  of  cleaning  has  worked  so  satisfactorily  in 
the  past  that  it  has  not  been  thought  necessary  to  introduce  mechanical  appliances. 
The  sand  is  removed  from  the  grit  chambers  by  two  endless  chain  bucket  elevators. 
Two  other  chambers  have  been  added,  fitted  with  a  mechanical  screening  plant  and 
with  a  traveling  bucket  dredger.  P 

The  sewage  passes  from  the  grit  chambers  to  the  settling  tanks,  which  are  17  in 
number,  and  arranged  on  each  side  of  a  main  feed  conduit.  The  total  capacity  of  the 
tanks  is  18,000,000  gallons  or  114  times  the  estimated  dry-weather  flow.  Up  to  the 
present,  the  sludge  has  been  discharged  into  lagoons  on  the  ground  for  temporary 
storage.  The  lagoons  now  cover  an  area  of  about  5  acres  and  have  a  working  depth 
of  12  to  18  inches.  After  being  partly  dried,  the  sludge  is  loaded  into  cars  and  taken 
to  the  country  to  be  dumped. 

Sixty  new  contact  beds  are  provided  for  in  the  new  scheme,  each  bed  having  an 
area  of  one-half  acre.  The  beds  are  composed  of  screened  clinker,  graded  from  coarse 
to  medium  size,  with  the  finest  on  top.   The  depth  is  4  feet. 


CHAPTER  III 


RAINFALL  AND  THE  RELATIONS  BETWEEN  THE  VOLUMES  OF 
DOMESTIC  SEWAGE,  STORM  WATER  AND  TIDAL 
WATER  IN  NEW  YORK  HARBOR 

The  sewerage  systems  of  New  York  and  other  municipalities  in  the  Metropolitan 
district  are  described  and  the  principles  of  their  design,  as  far  as  ascertainable,  are 
given  in  the  report  of  the  Commission  dated  April  30,  1910,  pages  217  to  361,  inclusive. 
The  quantities  of  domestic  sewage  are  there  stated  for  the  Metropolitan  district  and, 
so  far  as  they  relate  to  New  York  City,  have  been  given  in  revised  form  in  the  Commis- 
sion's preliminary  report  No.  VI,  dated  February,  1913.*  In  the  two  reports  mentioned 
will  be  found  data  giving  the  volumes  of  tidal  water.  The  rainfall  data  which  have 
been  compiled  by  the  commission  are  stated  for  the  first  time  in  this  place. 

The  volume,  intensity  and  frequency  of  rain-storms  have  an  important  bearing  on 
the  question  of  sewage  disposal,  especially  in  those  cases,  as  at  New  York,  where  the 
sewers  are  built  upon  the  combined  plan. 

With  respect  to  volume,  the  water  which  falls  in  the  built-up  parts  of  the  city 
during  the  course  of  a  year  in  the  form  of  rain  and  snow  and  flows  away  to  the  sewers 
bears  a  very  small  proportion  to  the  quantity  of  domestic  sewage.  The  volume  of 
storm  water  seems  greater  than  it  really  is,  probably  because  of  its  appearance  in  the 
streets  and  on  account  of  the  large  size  of  the  sewers  which  are  built  to  carry  it  off,  but 
it  is  to  be  remembered  that  there  are  many  days  when  no  storm  water  is  produced, 
whereas  the  drdinary  flow  of  domestic  sewage  is  continuous.  Excepting  in  rural  dis- 
tricts, where  little  or  no  sewage  is  produced,  the  volume  of  storm  water  is  small  as  com- 
pared with  the  dry-weather  flow. 

The  frequency  of  rain-storms  of  sufficient  intensity  to  wash  the  dirt  of  the  streets 
into  the  sewers  must  be  taken  into  consideration.  The  first  flush  of  storm  water  from 
a  city  is  often  more  foul  than  house  sewage,  and  the  more  intense  and  less  frequent 
the  storms,  the  greater  is  the  quantity  of  polluting  matter  which  is  likely  to  be  carried 
with  the  initial  rush.  In  addition  to  the  washings  of  the  streets,  the  deposits  which 
exist  in  some  parts  of  nearly  all  sewers  are  likely  to  be  scoured  away  and  these  may  add 
considerably  to  the  solid  matters  discharged  by  the  sewers. 

The  first  effect  of  a  storm  is  to  increase  both  the  volume  and  concentration  of  the 
sewage,  and  this  effect  is  greater  or  less  depending  on  the  violence  and  duration  of  the 
storm.  When  rain-storms  continue  for  long  periods  of  time  their  effect  is  to  dilute  the 
sewage.    The  scouring  and  flushing  actions  which  occur  at  first  gradually  cease  for 

*See  Part  II,  Chapter  II,  page  46  of  this  report. 


RAINFALL  AND  DILUTION  OF  SEWAGE 


483 


want  of  solid  matter  to  dissolve  or  wash  away  and  the  water  which  enters  the  sewers 
from  the  streets  and  roofs  becomes  less  polluted  than  the  ordinary  domestic  sewage. 

Allowance  for  Storm  Water 

It  is  customary  in  designing  sewage  disposal  works  which  are  to  deal  with  the  com- 
bined sewage  of  houses  and  streets  to  provide  a  plant  sufficient  to  handle  the  dry- 
weather  flow  and  some  of  the  first  flush  of  storm  water.  In  the  studies  made  by  this 
commission  for  main  drainage  and  disposal  works  for  New  York,  allowance  has  been 
made  for  storm  water  by  providing  for  twice  the  average  dry-weather  flow.  This  pro- 
vision gives  room  for  the  maximum  discharge  of  domestic  sewage,  which  may  be  50  per 
cent,  above  the  average  at  certain  hours  of  the  day  and  makes  it  possible  to  deal  with  a 
considerable  amount  of  storm  water,  provided  it  falls  at  a  time  when  the  ordinary 
domestic  flow  is  not  at  a  maximum. 

The  importance  of  giving  careful  consideration  to  the  rainfall  is  greater  in  design- 
ing collecting  systems  of  sewers  than  in  providing  for  final  disposition.  The  function 
of  such  sewers  is  not  only  to  carry  off  the  drainage  of  the  houses,  but  to  prevent  accu- 
mulations of  water  in  the  streets.  It  sometimes  happens,  when  excessive  falls  of  rain 
occur,  that  sewers  are  surcharged.  At  such  times  the  drainage  of  houses  is  interfered 
with  and  often  stopped,  in  which  case  cellars  may  be  flooded  and  other  serious  incon- 
venience produced. 

It  is  usually  impracticable  to  provide  combined  sewers  of  a  size  and  grade  sufficient 
to  carry  away  the  water  which  falls  in  storms  with  sufficient  promptness  to  insure  that 
inconvenience  from  flooding  shall  never  occur.  At  long  intervals  rainfalls  of  excep- 
tional severity  take  place,  and  to  provide  for  these,  sewers  would  have  to  be  built  so 
very  large  that  they  would  represent  a  considerable  investment  over  the  sum  required 
to  give  them  sufficient  capacity  for  all  the  ordinary  and  most  of  the  heavy  rains  which 
are  likely  to  fall. 

Fig.  21  shows  the  comparative  size  of  sewers  intended  to  accommodate  domestic 
sewage,  ordinary  storm  and  house  sewage  and  the  greatest  probable  amount  of  storm 
water  with  the  same  amount  of  house  sewage  as  is  provided  in  other  instances. 


Eoi  Greatest  Probable  Storm 
and  House  Sewage. 


For  Ordinary  Storm  House 
and  House  Sewage.  Sewage 
For  Densely  Populated  Area.  Aiona 
 ( 237  per  Acre )  


FIG.  21 

Relative  Sizes  of  Sewers  for  Combined  Storm  Sewage  and  House  Sewage 


484         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

The  assumption  upon  which  this  figure  has  been  drawn  is  that  the  area  is  popu- 
lated to  the  extent  of  about  237  persons  per  acre.  Under  some  circumstances  the 
volume  of  storm  water  may  be  nearly  80  times  the  volume  of  domestic  flow;  about  2 
per  cent,  of  the  annual  rainfall  may  reach  a  combined  sewer  in  15  minutes. 

Studies  have  been  made  by  the  commission  to  show  the  amount  of  storm  water 
entering  New  York  harbor  from  various  parts  of  New  York  City.  The  divisions,  areas 
and  volumes  of  domestic  sewage  correspond  with  Figures  1  and  2,  page  18,  and  Fig.  9, 
page  30,  of  the  report  of  this  commission  dated  August  1,  1912,  as  near  as  practicable, 
where  the  areas  were  tributary  to  the  various  parts  of  the  harbor  waters. 

The  rainfall  was  taken  from  the  United  States  Weather  Bureau  records  from  1875 
to  1912,  inclusive.  The  yearly  average  was  43.97,  the  minimum  35.73  and  the  maxi- 
mum 58.68  inches.  The  runoff  was  assumed  to  be  from  40  to  80  per  cent.,  according 
to  the  density  of  population  of  the  various  parts  of  the  drainage  areas. 

Table  XCII  has  been  prepared  to  show  the  estimated  relative  volumes  of  storm 
water  and  domestic  sewage  entering  various  parts  of  the  Harbor  from  New  York  City. 

TABLE  XCII 


Estimated  Relative  Volumes  op  Storm  Water  and  Domestic  Sewage  Entering 
Various  Parts  op  the  Harbor  from  New  York  City. 


Drainage  to 

Acres 

Millions  of  cubic  feet  Daily 

Per  cent,  of  Vol- 
ume of  Sewage 

Population 
Thousands 

Density 
Persons 
per 
Acre 

Net 

Parks 

Total 

Rain 

C 

Run-off 

Sewage 

Rain 

Run-off 

i 

5,122 

349 

5,471 

2.39 

85 

2.03 

33.50 

7.1 

6.1 

1,562.6 

306 

t 

8,783 

1,759 

10,542 

4.61 

60 

2.77 

40.29 

10.7 

6.9 

2,105.8 

239 

Upper  East  river. . 

3 

39,717 

2,431 

42,148 

18.43 

40 

7.37 

6.64 

277.6 

111.0 

304.8 

8 

Lower  East  river . 

16,852 

2,229 

19,081 

8.33 

80 

6.66 

64.6 

12.9 

10.3 

3,785.9 

198 

i 

53,659 

23.47 

50 

11.74 

27.20 

86.3 

43.2 

1,415.7 

26 

Kill  van  Kull 

6 

6,647 

2.91 

60 

1.75 

7.91 

36.8 

22.1 

432.9 

65 

Upper  bay  

t 

12,519 

458 

12,977 

5.69 

70 

3.98 

25.80 

22.1 

15.4 

1,617.9 

129 

'From  Harlem  river  to  the  Battery. 

includes  sewage  from  Hudson  area,  573  acres,  Harlem  river  to  N.  Line  of  City. 
'Agrees  with  Preliminary  Report  IV. 
♦Agrees  with  Preliminary  Report  III. 
•Agrees  with  Preliminary  Report  V. 

{Manhattan  and  Brooklyn  1960 
Queens  1950 
Bronx  1940 

C  Assumed  percentage  of  rain  flowing  to  streams. 

Table  XCII  shows  that  the  percentage  of  daily  rainfall  to  daily  sewage  is  about  7 
per  cent,  in  the  most  densely  populated  parts  of  the  city.  In  the  course  of  a  day  or  month 
or  year  there  is  about  ten  times  as  much  domestic  sewage  as  storm  water  entering  di- 


RAINFALL  AND  DILUTION  OF  SEWAGE 


485 


rectly  to  the  Lower  East  River.  It  will  be  observed  that  the  annual  rainfall  has  had 
a  wide  range  in  the  37  years  for  which  records  are  available.  The  minimum  of  35.73 
inches,  which  is  about  81  per  cent,  of  the  average,  occurred  in  1895  and  the  maxi- 
mum of  58.68,  or  about  133  per  cent,  of  the  average,  occurred  in  1889. 

Intensity  of  Rainfall 

In  regard  to  intensity  of  rainfall,  marked  variations  have  been  observed.  In  the 
month  of  September,  1882,  14.51  inches  fell,  or  about  one-third  of  the  total  annual 
average.  On  the  twenty-third  day  of  the  same  month  6.17  inches  fell  in  24  hours,  or 
42y2  per  cent,  of  the  monthly  rainfall  in  one-thirtieth  of  the  month. 

The  records  of  the  United  States  Weather  Bureau  have  been  examined  since  obser- 
vations were  begun  for  the  heaviest  rainfalls  which  have  occurred  in  brief  intervals  of 
time.  The  intensities  lasting  5,  10,  15  and  30  minutes  and  1  and  2  hours  have  been 
taken  from  the  records  and  are  here  presented.  The  earliest  records  were  made  in 
1896.  The  rainfall  in  5,  10  and  60  minutes  was  observed  from  this  time  forward  with 
the  exception  of  December,  1896,  June,  1897,  and  February,  1898.  The  records  for 
periods  of  15,  30  and  120  minutes  were  begun  in  January,  1903,  and  continued  to  the 
present  time. 

These  records  are  all  contained  in  Table  XCTII,  which,  for  convenience,  has  been 
arranged  to  show  the  intensity  of  precipitation  according  to  years,  months  and  the  brief 
periods  of  time  here  stated. 


TABLE  XCIII 

New  York  City — Greatest  Monthly  Precipitation  in  Inches  in  5-Minute,  10-Min- 
ute,  15-Minute,  30-Minute,  1-Hour  and  2-Hour  Periods,  1896  to  1911,  Inclusive. 


Year 


January 


5m.  10m.  15m.  30m.  lh.  2h 


February 


5m.  10m.  15m.  30m.  lh.  2h 


March 


5m.  10m.  15m.  30m.  lh.  2h 


1896. 
1897. 
1898. 
1899. 
1900. 
1901. 
1902. 
1903. 
1904. 
1905. 
1906. 
1907. 
1908. 
1909. 
1910. 
1911. 


.06 
.07 
.06 
.03 
.04 
.06 
.04 
.05 
.06 
.05 
.06 
.07 
.06 
.07 


.08 
.11 
.10 
.05 
.07 
.10 
.06 
.09 
.10 
.06 
.11 
.10 
.10 
.10 


.13 
.08 
.11 
.14 
.08 
.15 
.12 
.13 
.11 


.20 
.17 
.19 
.24 
.13 
.25 
.19 
.19 
.11 


.30 
.39 
.42 
.12 
.14 
.36 
.29 
.30 
.43 
.25 
.37 
.38 
.24 
.19 


.54 
.47 
.53 
.65 
.47 
.69 
.47 
.31 
.28 


.04 

.03 
.08 
.02 
.05 
.10 
.03 
.04 
.06 
.02 
.06 
.05 
.07 
.13 


.06 

.05 
.17 
.03 
.09 
.12 
.04 
.06 
.10 
.04 
.10 
.10 
.11 
.17 


.13 
.06 
.08 
.14 
.05 
.13 
.13 
.15 
.21 


.14 
.11 

.15 
.18 
.10 
.23 
.18 
.21 
.31 


.25 

.24 
.55 
.08 
.35 
.20 
.18 
.26 
.30 
.12 
.43 
.25 
.36 
.53 


.35 
.29 
.47 
.41 
.22 
.77 
.36 
.71 
.80 


.03 
.04 
.08 
.04 
.12 
.05 
.10 
.07 
.04 
.04 
.11 
.04 
.06 
.06 
.13 


.05 
.06 
.12 
.07 
.22 
.07 
.15 
.10 
.06 
.06 
.13 
.06 
.10 
.08 
.19 


.16 
.11 
.07 
.09 
.14 
.06 
.12 
.09 
.22 


.19 
.15 
.11 
.15 
.19 
.10 
.23 
.14 
.25 


.19 
.16 
.40 
.24 
.64 
.21 
.27 
.23 
.17 
.28 
.29 
.16 
.40 
.20 
.27 


.29 
.33 
.30 
.52 
.45 
.24 
.74 
.23 
.43 


Note. — Record  has  only  been  made  of  the  greatest  intensity  for  each  period  during  the  month.  Other  storms 
of  high  and  equal,  or  less,  intensity  may  have  occurred  during  the  same  month. 


486         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

TABLE  XCIII— Continued 


April 

May 

June 

5m. 

10m. 

15m. 

30m. 

lh. 

2h. 

5m. 

10m. 

15m. 

30m. 

lh. 

2h. 

5m. 

10m. 

15m. 

30m. 

lh. 

2h. 

.03 

.06 





.22 



.15 

.25 





.46 



.19 

.31 





.56 



.05 

.10 





.20 



.20 

.36 





.68 



.42 

.57 





.69 



.26 

.30 





.36 



.09 

.16 





.28 



.12 

.15 



.24 



.02 

.04 





.16 



.05 

.09 





.24 



.16 

.25 





.46 



.05 

.07 





.25 



.18 

.28 



— 

.98 



.26 

.50 





1.55 



.09 

.15 

.43 

.16 

.19 

.40 

.10 

.12 

.32 

.06 

.10 

.44 

.10 

.20 

.27 

.22 

.36 

.67 

.04 

.06 

.08 

.12 

.20 

.36 

.07 

.07 

.07 

.08 

.08 

.09 

.30 

.41 

.48 

.74 

1.30 

1.94 

.09 

.13 

.15 

.23 

.34 

.45 

.22 

.25 

.28 

.37 

.42 

.43 

.17 

.23 

.29 

.35 

.35 

.38 

.07 

.09 

.11 

.17 

.23 

.28 

.09 

.13 

.15 

.17 

.19 

.19 

.38 

.61 

.66 

.66 

.66 

.87 

.10 

.18 

.24 

.36 

.64 

.91 

.35 

.59 

.68 

.77 

.94 

1.06 

.15 

.23 

.26 

.32 

.42 

.48 

.10 

.15 

.20 

.25 

.28 

.37 

.15 

.20 

.23 

.31 

.47 

.62 

.09 

.11 

.13 

.19 

.26 

.37 

.08 

.11 

.13 

.26 

.42 

.62 

.24 

.34 

.39 

.45 

.81 

1.15 

.09 

.14 

.19 

.32 

.45 

.60 

.06 

.11 

.16 

.22 

.43 

.71 

.06 

.06 

.07 

.09 

.17 

.28 

.15 

.18 

.22 

.34 

.42 

.42 

.14 

.24 

.27 

.41 

.53 

.74 

.09 

.14 

.15 

.19 

.22 

.29 

.25 

.41 

.48 

.58 

.63 

.93 

.05 

.06 

.07 

.14 

.26 

.37 

.07 

.12 

.13 

.13 

.15 

.21 

.20 

.32 

.40 

.53 

.95 

1.04 

July 

August 

September 

5m. 

10m. 

15m. 

30m. 

lh. 

2h. 

5m. 

10m. 

15m. 

30m. 

lh. 

2h. 

5m. 

10m. 

15m. 

30m. 

lh. 

2h. 

.40 

.58 

1.04 

.19 

.32 

.39 

.23 

.27 

.47 

.28 

.40 

.85 

.32 

.46 

.75 

.18 

.26 

.53 

.34 

.44 

1.27 

.24 

.26 

.41 

.12 

.16 

.39 

.27 

.49 

1.42 

.31 

.43 

1.20 

.22 

.37 

.95 

.34 

.41 

.65 

.16 

.27 

.47 

.12 

.12 

.31 

.38 

.63 

1.29 

.48 

.82 

1.36 

.25 

.29 

.34 

.47 

.73 

.88 

.37 

.65 

.101 

.07 

.12 

.26 

.23 

.39 

.42 

.50 

.50 

.55 

.10 

.11 

.15 

.25 

.46 

.83 

.14 

.25 

.29 

.41 

.84 

1.10 

.19 

.27 

.27 

.48 

.59 

.63 

.40 

.64 

.78 

1.18 

1.66 

1.80 

.25 

.38 

.40 

.61 

.80 

1.10 

.74 

1.26 

1.63 

2.09 

2.30 

2.58 

.20 

.36 

.48 

.80 

.98 

.98 

.20 

.27 

.33 

.60 

1.00 

1.38 

.19 

.28 

.33 

.44 

.64 

.69 

.52 

.97 

1.22 

1.35 

1.36 

1.36 

.16 

.31 

.47 

.63 

.89 

.96 

.11 

.15 

.20 

.20 

.24 

.37 

.17 

.30 

.45 

.66 

.84 

.97 

.22 

.33 

.40 

.59 

.63 

.83 

.39 

.49 

.75 

1.14 

1.22 

1.52 

.15 

.29 

.30 

.47 

.74 

1.23 

.10 

.13 

.16 

.27 

.42 

.56 

.18 

.26 

.31 

.33 

.33 

.45 

.12 

.16 

.24 

.39 

.60 

.87 

.09 

.13 

.14 

.15 

.20 

.36 

.06 

.07 

.08 

.11 

.11 

.11 

.22 

.43 

.55 

.70 

.73 

.73 

.05 

.08 

.12 

.19 

.28 

.48 

.10 

.17 

.81 

.20 

.22 

.30 

.16 

.28 

.34 

.44 

.53 

.72 

.07 

.12 

.15 

.16 

.21 

.38 

October 

November 

December 

5m. 

10m. 

15m. 

30m. 

lh. 

2h. 

5m. 

10m. 

15m. 

30m. 

lh. 

2h. 

5m. 

10m. 

15m. 

30m. 

lh. 

2h. 

.03 

.05 

.19 

.05 

.08 

.18 

.08 

.12 

.18 

.09 

.18 

.47 

.07 

.11 

.45 

.36 

.53 

.57 

.06 

.10 

.31 

.10 

.14 

.24 

.07 

.09 

.27 

.06 

.08 

.17 

.06 

.08 

.20 

.17 

.27 

.88 

.14 

.21 

.53 

.05 

.08 

.32 

.09 

.11 

.23 

.02 

.03 

.14 

.04 

.07 

.26 

.19 

.32 

.57 

.03 

.04 

.11 

.09 

.15 

.32 

.28 

.41 

.65 

.99 

1.49 

2.42 

.08 

.12 

.12 

.15 

.26 

.31 

.02 

.04 

.06 

.11 

.20 

.39 

.12 

.19 

.26 

.38 

.66 

1.13 

.07 

.11 

.14 

.14 

.38 

.47 

.02 

.03 

.04 

.07 

.14 

.25 

.12 

.19 

.25 

.30 

.36 

.56 

.03 

.05 

.07 

.10 

.18 

.31 

.08 

.16 

.22 

.30 

.56 

.68 

.19 

.25 

.31 

.33 

.43 

.60 

.02 

.04 

.04 

.07 

.13 

.24 

.05 

.10 

.15 

.21 

.30 

.45 

.13 

.20 

.23 

.32 

.48 

.63 

.06 

.11 

.11 

.21 

.34 

.48 

.11 

.12 

.14 

.25 

.42 

.77 

.21 

.31 

.40 

.58 

.64 

.65 

.02 

.03 

.04 

.07 

.14 

.20 

.08 

.13 

.18 

.23 

.36 

.57 

.07 

.08 

.08 

.08 

.14 

.21 

.03 

.05 

.06 

.10 

.16 

.20 

.12 

.20 

.24 

.47 

.66 

.97 

.18 

.30 

.42 

.70 

.91 

1.31 

.04 

.08 

.11 

.20 

.37 

.63 

.02 

.03 

.05 

.09 

.18 

.35 

.09 

.10 

.13 

.19 

.31 

.42 

.04 

.08 

.12 

.21 

.34 

.65 

.03 

.06 

.07 

.10 

.15 

.24 

RAINFALL  AND  DILUTION  OF  SEWAGE 


487 


From  Table  XCIII,  Table  XCIV  has  been  prepared  to  show  the  variations  which 
have  occurred  in  the  rates  of  precipitation.  These  rates  have  varied  from  1  to  9  inches 
per  hour.  The  data  are  arranged  according  to  the  rate  of  precipitation  and  the  periods 
of  time  during  which  these  rates  were  continued.  The  greatest  rate  was  8  inches  per 
hour  and  this  was  continued  for  5  minutes. 


TABLE  XCIV 

Number  and  Percentage  op  Months  in  Which  the  Rate  op  Precipitation  Exceeded 

1  Inch  per  Hour. 

(See  Note  on  Page  6.) 


Period 


Total  Months 
Observed 


o 
W 

In 

V 
ft 

GO 

V 
J3 


J 
03 

s 

o 


1.00. . 

1.25. . 

1.50. . 

1.75. . 

2.00. . 

2.50. . 

3.00. 

3.50.. 

4.00. 

4.50. 

5.00. 

6.00. 

7.00. 

8.00. 

9.00. 


5  Min. 


186 


101 
80 
69 
63 
53 
36 
26 
18 
15 
10 
5 
3 
1 
1 
0 


54.3% 
43.0% 
37.1% 
33.9% 
28.5% 
19.4% 
14.0% 
9.7% 
'  8.1% 
;  5.4% 
■■  2.7% 

■  1-6% 

-  0.5% 

■  0.5% 

-  0.0% 


10  Min. 


186 


78 
64 
59 
42 
27 
19 
13 
8 
4 
3 
2 
1 
0 


41.9% 
34.3% 
31.7% 
22.6% 
14.5% 
10.2% 
'  7.0% 
'  4.3% 
■■  2.15% 

:  1.6% 
-  1-1% 

=  0.5% 
■  0.0% 


15  Min. 


108 


34 
23 
19 
13 
8 
7 
4 
2 
2 
2 
1 
1 
0 


31.4% 
21.3% 
17.6% 
12.0% 
'  7.4% 

:  6.5% 

'  3.7% 
-  19% 

a.  85% 

■  1.8% 

■  0.9% 

■  0.9% 
=0.0% 


30  Min. 


108 


20 
13 
7 
5 
4 
2 
1 
1 
1 
0 


18.5% 
12.0% 
6.5% 
4.6% 
■■  2.15% 

'  1.1% 

■  0.9% 

■  0.9% 

■  0.9% 

■  0.0% 


60  Min. 


186 


15 


10 


1 


1 


0 


=  8.1% 

> 

=  5.4% 

I 

=  1.6% 
=0.5% 

L 

=  0.5% 

> 

=  0.0% 


120  Min. 


108 


=  1.1% 

1 

=0.5% 

0 

=0.0% 


To  facilitate  the  use  of  the  data  contained  in  Tables  XCIII  and  XCIV  curves  have 
been  prepared  to  show  the  most  important  facts  with  regard  to  the  intensity  of  rainfall. 
Fig.  22  gives  the  frequency  of  rates  of  different  intensities  for  various  periods  of  time, 
arranged  according  to  the  percentage  of  months  in  which  they  have  occurred. 


488         DATA  KELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


Fig.  23  shows  the  frequency  of  various  intensities  which  have  lasted  for  5  minutes, 
arranged  so  as  to  indicate  the  number  of  times  which  they  have  occurred  per  year  and 
the  mean  interval  in  months  which  has  occurred  between  storms. 


Note:. 

Baaed  on  U.S.  Weather  Bureau 
Records  of  most  severe  Storm 
of  each  Month.  1890-1911 

BB — S 

8 

s 

o 

ffl  1 

u 
o. 

?  6 


-  6 

.3 


Number  of  Times  par  Year 
4      5      6       ?       8  9 


Mean  Interval  in  MonthB  between  Storms 
10      12      14      J6      18      JO      22     24      26     28      30     48    fit  86 

l        \        i        ■        ■        t        i        i        .        i        i        i        i  i 


FIG.  23 

Frequency  of  Rainfalls  of  Different  Intensities  for  6  Minute  Periods 

Manhattan 


RAINFALL  AND  DILUTION  OF  SEWAGE 


489 


Figs.  24,  25  and  26  are  uniform  with  Fig.  23  except  that  they  cover  rates  which 
were  maintained  for  longer  periods. 


Number  of  Timec  per  Year 
0              I               2              3              4               5  6 
—  l  l  i  1  i  I  1  1  1  1  i.  L 


Mean  Interval  ia  Months  between  Storms 
0       10      20      30      40      50      GO      70      80      90     100     110     120     130     140     150    1C0     ITU  180 

i  i  i  i  i  i  i  1  1  1  1  ;  1  1  1  , 

FIG.  24 

Frequency  of  Rainfalls  of  Different  Intensities  for  10  Minute  Periods 

Manhattan 


6.5 

Q 

m 

1.4.5 

9 

a. 

1* 
a 

£35 

"a 
a  3 

1 

Note:- 

Based  on  U.S.  Weather  BDrean 
Records  of  most  severe  Storm 
of.  each  Month.  1903-1911 

c 

tor**19  m 

— ^S2^~- 

■SS.S 

1 

1.6 
1 

^ear 

)  0 

6 

N 
1 

imber  of  Ti 
6 

mes  per  Ye 

!  t 

ar 

5  J 

1  3 

s 

L 

1 

Mean  Interval  in  Months  between  Storms 
0              10             20             30             40             SO             «0             70             80  90 
1  1  1  1  1  1  1  1  1  1  1  1 

FIG.  25 

Frequency  of  Rainfalls  of  Different  Intensities  for  15  Minute  Periods 

Manhattan 


o 
S 


a  2.5 
1 


^en_St2 

rxn>> 

■geB£. 

■Note:- 

Based  on  U.S.  Weather  Bureau 
Records  of  most  severe  Storm 
of  each  month,  1903-1911. 

Vear  0 

Number  of  Times  per  Year 
0       0.25      0.5      0.75       1.      1.25      1.5      1.76  8. 


2.25      8.5  2.75 


Mean  Interval  in  Months  between  Storms 
100      125      150      176      200      225  850 


275      800      325  350 


FIG.  26 

Frequency  of  Rainfalls  of  Different  Intensities  for  30  Minute  Intervals 

Manhattan 


490 


DATA  RELATING  TO  THE  PROTECTION  OP  THE  HARBOR 


Example  of  a  Severe  Rainfall 
A  rain-storm  of  unusual  severity  occurred  in  New  York  on  October  1,  1913.  The 
study  which  the  commission  made  of  it  will  serve  to  show  how  beneficial  a  rainfall  may 
be  in  diluting  the  polluted  water  of  the  harbor.  In  this  study  the  harbor  has  been  con- 
sidered to  consist  of  ten  divisions  defined  by  the  commission  in  its  previous  reports. 
The  rainfall,  as  observed  at  a  number  of  stations  maintained  chiefly  by  the  Weather 
Bureau,  has  been  computed  for  the  drainage  areas  tributary.  The  runoff  data  for  the 
land  surfaces  within  the  Metropolitan  district  are  based  upon  the  figures  stated  in 
Table  XCII,  increased  somewhat  because  of  the  unusual  length  and  character  of  the 
rainfall. 

The  rain  gauge  records  used  were  those  of  the  Weather  Bureau  stations  at  the 
Whitehall  Building  and  Central  Park  in  Manhattan,  the  Brooklyn  Eagle  Building  in 
Brooklyn,  of  the  Sewer  Bureau  at  the  Bronx  Borough  Hall,  Westchester  and  Richmond 
Borough  Hall  and  of  the  City  Engineer  at  the  Newark  City  Hall.  The  location  of  the 
rain  gauges  from  which  the  rainfall  records  were  taken  is  indicated  in  Fig.  27. 


FIG.  27 
Rain  Gauge  Stations 

The  records  from  the  foregoing  gauges  varied  somewhat  so  that  it  seemed  desir- 
able to  take  an  average  of  two  or  more  to  show  the  amount  of  rain  which  fell  in  the 
different  areas.  Some  idea  of  the  character  of  the  storm,  particularly  the  varying 
rates  of  precipitation  can  be  obtained  from  Fig.  28,  which  has  been  prepared  from  data 
collected  at  the  Weather  Bureau  Office  in  the  Whitehall  Building  near  the  center  of  the 
Metropolitan  district. 


RAINFALL  AND  DILUTION  OF  SEWAGE 


491 


i.OOA-M.         8.00  9.00  10.00  11.00  12.00  1.00  P.M.        2.00  3.00  *.00  5.00  6.00  P.M. 


FIG.  28 

Intensities  of  Rainfall,  Storm  of  October  1,  1913,  as  Observed  by  the  U.  S.  Weather  Bureau, 

at  Whitehall  Building,  New  York  City 

Fig.  28  shows  that  the  storm  was  characterized  by  low  rates  of  precipitation  from 
7  a.  m.  until  about  noon,  when  the  severity  increased  until  between  2  and  3  in  the  after- 
noon, when  it  reached  a  maximum.  After  1  o'clock  the  rate  of  rainfall  was  compara- 
tively insignificant.  During  the  preceding  da;\  the  weather  had  been  cloudy  with  slight 
precipitation.  At  its  height  there  was  a  period  of  5  minutes,  during  which  0.41  inch  of 
rain  fell,  this  being  8.5  per  cent,  of  the  total  of  the  storm.  During  10  minutes  0.77  inch 
fell,  or  15  per  cent,  of  the  total.  In  30  minutes  a  fall  of  1.64  was  recorded,  or  32  per 
cent,  of  the  total. 

Table  XCV  shows  the  volume  of  water  which  was  discharged  on  land  and  the  vol- 
ume of  rain  which  fell  upon  water  surfaces  in  the  Metropolitan  district  as  a  result  of 
the  storm  of  October  1. 

TABLE  XCV 

Volume  of  Water  Which  Was  Discharged  on  Land  and  the  Volume  of  Rain 
Which  Fell  Upon  Water  Surfaces  in  the  Metropolitan  District  as  the  Result 
of  the  Storm  of  October  1,  1913. 


FROM  LAND 


Division 

Trib.  Area 
Acres 

Rainfall 
Inches 

Rainfall 
Feet 

Per  cent. 
Run-off 

Total 
Acre-Feet 

Amount 
Mil.  Gal. 

12,100 

4.39 

.366 

70 

3,099 

1,012 

Hudson  river  

11,200 

5.40 

.450 

90 

4,541 

1,485 

36,400 

3.61 

.301 

55 

6,020 

1,968 

19,100 

4.96 

.413 

85 

6,710 

2,192 

15,100 

5.82 

.485 

75 

5,450 

1,781 

Kill  van  Kull  

12,600 

7.69 

.641 

70 

5,654 

1,849 

Jamaica  bav  

53,700 

4.59 

.383 

65 

13,350 

4,362 

Newark  bay  

114,400 

6.80 

.567 

55 

45,050 

14,730 

Arthur  Kill  

80,700 

7.69 

.641 

65 

33,600 

10,985 

Lower  bay  

24,700 

6.14 

.512 

65 

8,220 

2,688 

43,052 

492 


DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


TABLE  XCV— Continued 

RAINFALL  ON  WATER 


J-TVlSlOn 

Area 
Acres 

Rainfall 
Feet 

Volume 
Mil.  Gal. 

Volume 
from  Land 

Total  Volume 
Entering  Harbor 

Mil  finl 

Mil.  Gal. 

Mil.  cu.  ft. 

Harlem  river  

639 

.366 

76 

1,012 

1,088 

145.5 

9,670 

.450 

1,422 

1,485 

2,907 

388.6 

Upper  East  river  

6,409 

.301 

631 

1,968 

2,599 

347.4 

Lower  East  river  

2,738 

.413 

370 

2,192 

2,562 

342.6 

12,485 

.485 

1,981 

1,781 

3,762 

503.3 

Kill  van  Kull  

659 

.641 

138 

1,849 

1,987 

265.6 

Jamaica  bay  

13,760 

.383 

1,724 

4,362 

6,086 

814.0 

Newark  bay  

5,158 

.567 

955 

14,730 

15,685 

2097.0 

Arthur  Kill  

2,662 

.641 

558 

10,985 

11,543 

1543.0 

78,950 

.512 

13,155 

2,668 

15,843 

2118.0 

Total  storm  water  entering  harbor 

64,062 

8565.0 

From  Table  XCV  it  appears  that  the  fall  of  rain  approximately  in  11  hours  from 
7  A.  m.  to  6  P.  M.  varied  between  3.61  in  the  Upper  East  river  section  to  7.67  in  the 
neighborhood  of  Staten  Island.  The  total  amount  of  water  which  ran  off  to  the  harbor 
according  to  these  calculations  amounted  to  43,052  million  gallons.  A  large  amount  of 
rain  fell  directly  upon  the  water  surfaces  and  this  increased  the  total  precipitation 
which  reached  the  harbor  to  64,062  million  gallons,  or  8,565  million  cubic  feet.  This 
is  equivalent  to  216,200  cubic  feet  per  second  for  11  hours. 

Table  XCVI  has  been  prepared  with  the  object  of  comparing  the  volume  of  storm 
water  discharged  on  October  1  with  the  volumes  of  water  already  in  the  harbor  and 
passing  through  the  harbor  under  ordinary  weather  and  tidal  conditions. 

TABLE  XCVI 

Comparison  op  the  Volume  of  Storm  Water  Discharging  on  October  1  With  the 
Volume  op  Water  Already  in  the  Harbor  and  Passing  Through  the  Harbor 
Under  Ordinary  Weather  and  Tidal  Conditions. 


i 


Division 


Harlem  river  

Hudson  river  

Upper  East  river . . . 
Lower  East  river 

Upper  bay  

Kill  van  Kull  

Jamaica  bay  

Newark  bay  

Arthur  Kill  

Lower  bay  


Entire  harbor,  except 
Lower  bay  


Total  storm 
water  entering 
Mil.  cu.  ft. 


145.5 
388.6 
347.4 
342.6 
503.3 
265.6 
814.0 
2097.0 
1543.0 
2118.0 


8565.0 


6447 


Volume  below 
M.  L.  W. 
Mil.  cu.  ft. 


285 
12,330 
5,512 
4,174 
12,970 
728 
2,258 
1,542 
1,735 


41,534 


Ratio 
2:3 


1:2 
1:32 
1:16 
1:12.2 
1:26 
1:2.7 
1:2.8 
1.4:1 
1:1.1 


1:6.4 


Tidal  Prism. 
Mil.  cu.  ft. 


148 
1,697 
1,869 

552 
2,541 

150 
2,309 
1,071 

743 


11,080 


6 

Ratio 
2:5 


1:1 

1:4. 

1:5. 

1:1. 

Ira. 
1.8:1 

1:2.8 
1.9:1 
2.1:1 


1:1.7 


Resultant 
flow  towards 
Sandy  Hook 
Mil.  cu.  ft. 


15 
1,087 
*115 
100 
1,283 
88 
24 
105 
33 


fl,315 


Ratio 
2:7 


9.7:1 
1:2.8 
3:1 
3.4:1 
1:2.5 
3:1 
34:1 
20:1 
47:1 


4.9:1 


*  Differs  from  Lower  East  river  by  amount  of  resultant  flow  of  Harlem  river, 
t  Resultant  flow  through  Narrows  increased  by  that  of  Arthur  Kill. 


RAINFALL  AND  DILUTION  OF  SEWAGE 


493 


Table  XCVI  shows  that  the  amount  of  rain  which  fell  directly  upon  the  water  sur- 
faces of  the  harbor  above  the  Narrows  and  ran  off  from  the  land  immediately  tribu- 
tary to  the  harbor  was  equivalent  to  216,200  cubic  feet  per  second.  This  is  9  times  the 
average  land  water  discharge  rate  of  the  entire  Hudson  river ;  IT  times  the  dry- weather 
land  water  discharge  rate  of  that  stream  and  7%  times  the  resultant  rate  of  ebb  flow 
of  harbor  water  through  the  Narrows. 

The  total  volume  of  8,565  million  cubic  feet  is  equal  to  4  times  the  total  mean  daily 
land  water  discharge  volume  of  the  Hudson  river,  ~y2  times  the  mean  daily  land  water 
discharge  of  that  stream  and  6%  times  the  total  resultant  ebb  flow  of  harbor  water 
through  the  Narrows  in  one  tidal  cycle  of  12  lunar  hours. 

Comparing  the  volumes  of  storm  water  entering  the  various  divisions  of  the  harbor 
contained  in  those  divisions  at  mean  low  tide,  in  the  tidal  prism  and  in  the  resultant 
flow  toward  Sandy  Hook,  a  number  of  facts  become  apparent.  The  quantity  of  rain 
water  which  entered  the  Harlem  river  was  equal  to  the  tidal  prism  of  that  strait  or 
the  volume  of  water  between  the  levels  of  high  and  low  tide.  Approximately  the  same 
is  true  for  the  Lower  East  river.  The  rain  water  which  entered  Newark  bay  was  about 
twice  the  tidal  prism. 

With  respect  to  the  proportion  between  the  rain  water  and  the  normal  net  ebb 
flow  through  the  various  sections,  the  following  facts  were  established :  About  3V2 
times  as  much  rain  water  entered  the  Lower  East  river  as  there  is  net  ebb  flow  through 
that  section.  Nearly  ten  times  as  much  rain  water  entered  the  Harlem  river  as  there 
is  resultant  flow  through  that  strait.  In  Newark  bay  and  Jamaica  bay  the  proportion 
was  very  much  greater.  The  rain  water  which  entered  Upper  New  York  bay  was 
almost  one-half  of  the  volume  of  the  net  ebb  flow  through  that  part  of  the  harbor. 

In  all  cases  these  ratios  are  based  upon  the  rainfall  which  fell  upon  the  water  sur- 
faces and  that  which  ran  off  from  the  areas  of  sections  of  the  harbor  mentioned.  In  no 
case  is  the  rainfall  upon  neighboring  territories  or  water  surfaces  included. 

Considering  the  entire  harbor,  except  Lower  New  York  bay,  it  appears  that  nearly 
5  times  as  much  rain  water  entered  the  harbor  as  the  net  seaward  discharge  under 
ordinary  circumstances.  Speaking  generally,  the  rain  water  was  almost  equal  to  the 
tidal  prism  and  was  equivalent  to  about  one-sixth  of  the  total  water  present  beneath  the 
level  of  mean  low  water. 

Ratios  of  Sewage  to  Water  in  the  Harbor 
Some  calculations  of  the  ratios  of  sewage  to  water  in  New  York  harbor  have  been 
made  by  the  Metropolitan  Sewerage  Commission  which  deal  with  comparatively  small 
parts  of  the  harbor  and  are  consequently  not  greatly  affected  by  the  errors  which  are 
generally  inseparable  from  such  computations.  But  all  calculations  of  this  kind  should 
be  regarded  as  crude  approximations  of  the  truth. 


494 


DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


There  are  three  divisions  of  the  water  with  which  it  is  of  interest  to  compare  the 
sewage.  First,  the  volume  of  water  which  is  contained  in  the  vicinity  of  an  outlet  at 
mean  low  tide;  second,  the  volume  of  the  tidal  prism  or  quantity  of  water  in  the  vicinity 
between  the  levels  of  low  and  high  tide;  third,  the  net  ebb  flow  past  the  point  where 
the  sewage  is  emptied. 

The  Metropolitan  Sewerage  Commission  has  divided  New  York  harbor  into  ten  sec- 
tions and  the  quantities  of  sewage  which  were  discharged  directly  into  these  sections 
in  1910  have  been  estimated;  the  quantities  of  water  in  each  section  below  mean  low 
tide,  in  the  tidal  prism,  and  the  net  ebb  flow  through  the  section  have  been  computed 
and  the  ratio  between  the  sewage  and  the  water  has  been  calculated.  Calculations 
based  on  estimates  of  future  quantities  of  sewage  have  also  been  made. 

In  addition  to  these  computations,  estimates  have  been  made  of  the  aggregate 
weight  of  sewage  impurities  which  are  tributary  to  each  section.  These  calculations 
are  based  on  a  definite  composition  of  the  sewage  which  is  assumed  and  taken  to  be 
uniform  for  the  whole  territory.  The  composition  assumed  is  that  of  the  standard 
sewage  as  shown  in  Table  III,  Part  II,  Chap.  II,  page  47  of  this  report.  The  volume 
of  the  sewage  for  the  year  1910  is  based  upon  the  public  water  supply.  The  volume  ex- 
pected in  future  is  also  founded  upon  anticipations  of  the  drinking  water  requirements. 
The  per  capita  volume  of  sewage  being  stated,  it  will  be  possible  at  any  time  to  correct 
the  estimates  of  weight  of  impurities  discharged  into  the  harbor  in  case  either  the  com- 
position or  volume  of  the  sewage  becomes  known.  It  is  improbable  that  such  knowl- 
edge can  be  obtained  until  main  drainage  works  are  built. 

It  has  seemed  desirable  to  calculate  the  quantities  of  sewage  materials  which  would 
be  discharged  into  the  various  sections  of  the  harbor  in  case  the  sewage  was  first  passed 
through  works  for  the  more  or  less  complete  removal  of  the  impurities.  The  processes 
of  treatment  which  have  been  thought  most  worthy  of  consideration  in  this  connection 
are  such  as  have  been  well  established  by  experience.  Screens  are  considered  because 
of  their  compactness  and  ability  to  operate  with  varying  quantities  of  sewage  and  small 
head.  Settling  basins  have  been  included  because  of  their  almost  universal  employ- 
ment in  sewage  purification  works  and  their  efficiency  in  removing  suspended  matter. 
Chemical  precipitation  has  been  considered  because  it  is  one  of  the  most  efficient  means 
for  removing  both  suspended  and  dissolved  matter  at  one  process.  Sprinkling  filters 
have  been  included,  since  they  represent  the  most  effective  means  of  oxidizing  the  sew- 
age impurities  in  a  given  area  of  land.  It  would  be  feasible,  and  it  is  customary  where 
a  high  degree  of  purification  is  required,  to  combine  two  or  more  of  these  processes  in 
a  given  plant. 

The  least  effective  process  which  seems  worth  considering  for  the  sewage  which  is 
to  be  discharged  into  the  harbor  is  screening,  and  the  highest  degree  of  purification 
practicable  in  most  cases  in  the  territory  where  the  sewage  is  produced  is  screening 


RAINFALL  AND  DILUTION  OF  SEWAGE 


495 


and  rapid  settlement.  More  purification  than  this  would  require  a  greater  amount  of 
land  than  is  procurable  except  at  great  cost  and  involve  probable  nuisance  from  odors 
and  flies. 

Estimates  of  the  quantities  of  sewage  discharged  into  New  York  harbor  shows  that 
all  sections  do  not  receive  an  equal  share  of  pollution ;  the  analyses  of  the  water  show 
that  the  circulation  of  the  tide  is  insufficient  to  distribute  satisfactorily  the  excessive 
burden  which  some  sections  receive.  Some  parts  of  the  harbor  are  much  more  polluted 
than  others,  the  region  of  greatest  pollution  being  close  to  the  most  densely  settled 
part  of  New  York  City.  The  Lower  East  river  and  Harlem  receive  large  quantities  of 
sewage  from  both  shores. 

TABLE  XCVII 

Volumes  of  Water  at  Low  Tide  in  the  Tidal  Prism  and  the  Net  Discharge  from 
the  Several  Divisions  of  the  Harbor.  The  Quantities  are  Expressed  as 
Million  Cubic  Feet. 


Division  of  the  Harbor 

Volume 
of  Water 

Below 
Mean  Low 
Tide 

Tidal 
Prism 

Net  Ebb 
Flow  in 
12  Lunar 
Hours 

Harlem  river  

285 

148 

15 

Hudson  river,  Batterv  to  Mt.  St.  Vincent  

12,330 

1,697 

1,087 

Upper  East  river  

5,512 

1,869 

4,174 

552 

ioo 

12,970 

2,541 

1,283 

Newark  bay  

1,542 

1,071 

105 

Kill  van  Kull  

728 

150 

88 

2,258 

2,307 

39,799 

10,335 

Table  XCVII  was  prepared  partly  from  tidal  data  computed  by  this  commission  and 
partly  from  information  supplied  by  the  United  States  Coast  and  Geodetic  Survey  in 
1909  as  a  result  of  studies  which  were  made  in  response  to  this  commission's  request. 

It  will  be  seen  from  Table  XCVII  that  the  Upper  bay  contains  more  water  at  low 
tide,  has  a  larger  tidal  prism  and  has  a  larger  net  discharge  of  water  than  has  any  other 
part  of  the  harbor.  The  Hudson  river  is  a  close  second  in  volume  at  low  tide,  but  it  has 
a  smaller  prism  and  net  flow  than  the  Upper  bay.  The  tidal  prism  and  volume  of  water 
at  low  tide  are  nearly  the  same  in  Jamaica  bay  and  Newark  bay,  from  which  it  appears 
that  these  bodies  of  water  are  almost  half  renewed  at  each  tide. 

In  the  Lower  East  river,  the  tidal  prism  is  one-sixth  the  volume  of  water  which 
lies  beneath  the  level  of  mean  low  tide  and  the  net  ebb  flow  is  about  one  twenty-seventh 
of  it.  Nowhere  else  in  the  metropolitan  district  is  the  net  ebb  flow  so  small  in  compari- 
son with  the  tidal  prism  or  volume  of  water  at  low  tide.  Large  as  is  the  volume  of 
water  in  this  division,  it  is  evident  that  there  is  not  a  great  deal  of  new  water  passing 
through  it.    In  the  Harlem  also,  the  tidal  prism  is  large  and  the  net  ebb  flow  small 


496 


DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


when  compared  with  the  volume  of  water  at  mean  low  tide.  From  these  figures,  it  ap- 
pears that  such  refreshing  action  as  the  Lower  East  river  and  Harlem  river  receive  is 
due  to  diffusion  with  cleaner  water  at  the  two  ends  of  these  streams  and  that  little 
renewal  occurs  by  actual  displacement  with  water  from  a  neighboring  section.  Large 
though  the  Lower  East  river  seems  to  be  and  swift  as  are  its  currents,  it  has  only  one- 
tenth  as  much  net  ebb  flow  as  the  Hudson. 

To  facilitate  computations  which  will  be  described  later,  the  quantities  of  sewage 
discharged  into  the  several  divisions  of  the  harbor  have  been  converted  from  gallons  per 
24  hours  to  cubic  feet  per  12  lunar  hours.    The  results  are  recorded  in  Table  XCVIII. 

TABLE  XCVIII 

Volume  of  Sewage  Directly  Tributary  to  the  Several  Divisions  of  the  Harbor. 


Division  of  the  Harbor 


Harlem  river  

Hudson  river  

Upper  East  river 
Lower  East  river 

Upper  bay  

Newark  bay  

Kill  van  Kull.... 
Jamaica  bay .... 


Directly  Tributary 
Million  Cu.  Ft.  per  12 
Lunar  Hours 


Year  1910 

Year  1940 

6.9 

17.5 

9.2 

20.9 

1.5 

6.9 

17.1 

31.5 

4.4 

8.2 

0.9 

2.1 

0.5 

1.6 

3.7 

11.3 

TABLE  XCIX 

Ratios  of  the  Volume  of  Sewage  Directly  Tributary  per  12  Lunar  Hours  to  the 
Volume  of  Water  in  the  Harbor  at  Mean  Low  Tide.  The  Quantities  Given 
are  in  Millions  of  Cubic  Feet. 


Division  of  the  Harbor 


Harlem  river  

Hudson  river .... 
Upper  East  river. 
Lower  East  river . 

Upper  bay  

Newark  bay  

Kill  van  Kull. . . . 
Jamaica  bay  


Sewage  Tributary  to  the  Division 

Water  in 

the 
Division 

Year  1910 

Year  1940 

Volume 

Ratio 

Volume 

Ratio 

285 
12,330 
5,512 
4,174 
12,970 
1,542 
728 
2,258 

6.9 
9.2 
1.5 
17.1 
4.4 
0.9 
0.5 
3.7 

1:41 

1:1350 

1:3675 

1:244 

1:2920 

1:1680 

1:1470 

1:550 

17.5 

20.9 
6.9 

31.5 
8.2 
2.1 
1.6 

11.3 

1:16 

1:590 

1:790 

1:132 

1:1580 

1:740 

1:460 

1:180 

39,799 

44.2 

1:900 

100 

1 : 398 

Table  XCIX, which  is  prepared  from  data  contained  in  Tables  XCVII  and  XCVIII, 
emphasizes  the  proportionately  heavy  sewage  burden  which  is  now,  and  in  future  would 


RAINFALL  AND  DILUTION  OF  SEWAGE  497 

be,  placed  upon  the  Lower  East  river.  The  ratio  of  sewage  to  water  at  mean  low  tide 
which  was  1  to  244  in  1910  would  be  1  to  132  by  1940.  A  notably  low  ratio  is  that  of 
the  Kill  van  Kull  which  was  1  to  1470  in  1910  and  would  be  1  to  460  by  1940.  This  body 
of  water  received  much  of  its  pollution  from  neighboring  bodies  of  water.  The  pollu- 
tion of  Newark  bay  will  increase  by  direct  contributions  of  sewage  until  the  ratio  which 
was  1  to  1680  iu  1910  will  be  1  to  740  by  1940  unless  measures  are  taken  to  keep  the 
sewage  out  of  it. 


TABLE  C 

Ratios  of  the  Volume  of  Sewage  Directly  Tributary  to  the  Volume  of  Water  in 
the  Tidal  Prism.  The  Quantities  Given  are  in  Millions  of  Cubic  Feet. 


Sewage  Tributary  to  the  Division 

Water 

Division  of  the  Harbor 

in  the 

Year  1910 

Year  1940 

Prism 

Volume 

Ratio 

Volume 

Ratio 

148 

6.9 

1:21.4 

17.5 

1 

8.5 

Hudson  river  

1,697 

9.2 

1: 185 

20.9 

1 

81 

Upper  East  river  

1,869 

1.5 

1:1246 

6.9 

1 

271 

Lower  East  river  

552 

17.1 

1:323 

31.5 

1 

17.5 

Upper  bay  

2,541 

4.4 

1:570 

8.2 

1 

310 

Newark  bay  

1,071 

0.9 

1:1170 

2.1 

1 

510 

Kill  van  Kull  

150 

0.5 

1:300 

1.6 

1 

94 

2,309 

3.7 

1:540 

11.3 

1 

175 

10,337 

44.2 

1:229 

100.0 

1 

101 

Table  C  has  been  prepared  from  Tables  XCVII  and  XCVIII  and  shows  the  remark- 
ably small  ratios  which  exist  between  the  sewage  and  tidal  prism  in  most  of  the  di- 
visions of  the  harbor.  The  smallest  occurs  in  the  Harlem,  1  to  21.4,  although  the  Lower 
East  river,  1  to  32.3,  is  very  low  for  the  year  1910.  In  1940  the  tidal  prism  will  be 
only  8V2  times  the  volume  of  sewage  discharged  directly  into  the  Harlem  and  in  the 
Lower  East  river  only  17y2  times  the  quantity  of  sewage  received. 

Unlike  the  ratio  of  sewage  to  water  below  mean  low  tide,  the  relation  of  sewage  to 
the  tidal  prism  is  comparatively  large  in  Newark  bay  and  will  be  considerable  in  1940. 
This  division  of  the  harbor,  which  was  comparable  with  the  Lower  East  river  in  Table 
XCIX,  resembles  the  Hudson  river,  where  the  pollution  is,  and  probably  will  remain, 
large. 

The  quantities  of  water  passing  through  each  division  in  their  relation  to  the  volume 
of  sewage  directly  discharged  are  shown  by  Table  CI,  which  was  prepared  from  Tables 
XCVII  and  XCVIII. 


498         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


TABLE  CI 

Ratio  op  the  Volume  op  Sewage  Directly  Tributary  per  12  Lunar  Hours  to  the 
Net  Ebb  Flow.  The  Quantities  Given  are  in  Millions  op  Cubic  Feet. 




Sewage  Tributary  to  the  Division 

Net 

Division  of  the  Harbor 

Ebb 

Year  1910 

Year  1940 

Flow 

Volume 

Ratio 

Volume 

Ratio 

15 

6.9 

1:2.2 

17.5 

1:0.85 

Hudson  river  

1,087 

9.2 

1:119 

20.9 

1:52 

1.5 

6.9 

ioo 

17.1 

1:5.9 

31.5 

1:3.2 

1,283 

4.4 

1:288 

8.2 

1:156 

105 

0.9 

1:114 

2.1 

1:50 

Kill  van  Kull  

88 

0.5 

1:178 

1.6 

1:55 

24 

3.7 

1:6.5 

11.3 

1:2.1 

2,702 

44.2 

1:61 

100.0 

1:27 

The  small  amount  of  dilution  from  the  net  ebb  flow  which  the  sewage  which  was 
discharged  into  the  Lower  East  river  received  in  1910  and  will  receive  in  1940  is  even 
more  graphically  indicated  in  this  table  than  in  its  predecessors.  By  1910  there  will 
be  more  sewage  discharged  into  the  Harlem  than  there  will  be  tidal  water  passing 
through  that  stream.  There  will  be  about  three  times  as  much  tidal  water  as  sewage 
passing  out  of  the  Lower  East  river.  The  Hudson  river  and  Upper  New  York  bay 
alone  seem  to  be  comparatively  well  supplied  with  water  available  for  flushing 
purposes. 

Table  CII  shows  the  number  of  tons  of  the  various  constituents  of  the  sewage  based 
on  the  composition  shown  in  Table  III,  Part  II,  Chap.  II,  page  47  of  this  report,  and 
the  volume  shown  in  Table  XCVIII,  page  504.  It  will  be  seen  that  in  every  important 
respect  the  Lower  East  river  receives  a  greater  weight  of  contaminating  matters  than 
does  any  other  division  of  the  harbor,  irrespective  of  its  size.  Next  comes  the  Hudson 
river,  followed  by  the  Harlem.  The  total  weight  of  sewage  materials  discharged  into 
the  Kill  van  Kull  and  Newark  bay  is  small  as  compared  with  the  quantities  of  pollut- 
ing matters  discharged  into  the  Lower  East  river. 


RAINFALL  AND  DILUTION  OF  SEWAGE 
TABLE  CII 


499 


Solid,  Organic  and  Volatile  Matters  Contained  in  the  Sewage  Directly  Tributary 
to  the  Several  Divisions  op  the  Harbor.  The  Quantities  are  Expressed  as 
Tons  op  2,000  lbs.  per  12  Lunar  Hours. 


Division  of  the 
Harbor 

Year 

Suspended 

Solid 
Matters 

Organic  and  Volatile  Matters 

Total 

Dissolved 

Suspended 

Nitro- 
genous 

Fat,  etc. 

Carbon 

/ 

1910 
1940 

52 
111 

70 
148 

35 
74 

35 
74 

26 
56 

9 

18 

35 
74 

1910 
1940 

65 
126 

87 
168 

43 
84 

44 
84 

33 
63 

11 
21 

43 
84 

Upper  East  river . . 

1910 
1940 

12 
43 

16 

57 

8 
29 

8 
28 

6 
21 

2 
7 

8 
29 

Lower  East  river. . 

1910 
1940 

133 
209 

178 

279 

89 
139 

89 
140 

67 
105 

22 
35 

89 
139 

1910 
1940 

34 
59 

45 
79 

23 
40 

22 
39 

17 

30 

6 
10 

23 
40 

1910 
1940 

7 
13 

9 

18 

4 

9 

5 
9 

3 
7 

1 

2 

4 

9 

Kill  van  Kull 

1910 
1940 

3 
9 

4 

12 

2 
6 

2 
6 

2 
4 

0.6 
2 

2 
6 

Jamaica  bay  

•  I 

1910 
1940 

23 
59 

30 
79 

15 
39 

15 
40 

11 

30 

4 
10 

15 

39 

Total  

■  t 

1910 
1940 

329 
629 

439 
840 

219 
420 

220 
420 

165 
318 

55.6 
105 

219 
420 

Table  CIII,  which  has  been  prepared  from  Tables  XCVI  and  XCVIII,  shows  the 
weight  of  sewage  ingredients  which  will  be  discharged  into  the  harbor  in  1910  and  1940, 
assuming  that  the  sewage  is  first  passed  through  certain  forms  of  treatment  with  the  ob- 
ject of  removing  impurities.  The  efficiency  of  the  treatment  employed  has  been  assumed 
as  follows:  The  screens  remove  15%  of  suspended  matter  and  10%  of  organic  matter; 
sedimentation  60%  of  suspended  matter  and  30%  of  organic  matter;  chemical  precipi- 
tation 85%  of  suspended  matter  and  50%  of  organic  matter;  sprinkling  filters  90%  of 
suspended  matter  and  70%  of  organic  matter. 

It  will  be  observed  that  the  use  of  any  of  these  processes  would  be  beneficial,  but 
that  the  residue  to  be  discharged  after  screening  or  sedimentation  would  still  leave 
very  large  quantities  of  polluting  matter  to  go  into  the  water.  Chemical  precipitation 
and  the  use  of  sprinkling  filters  would  probably  furnish  all  the  relief  needed  for  as 
many  years  as  can  now  be  anticipated.  As  has  been  shown  elsewhere  in  this  report, 
however,  these  latter  processes  are  not  applicable  unless  the  sewage  is  carried  to  some 
point  far  removed  from  its  present  source  for  treatment. 


500         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

TABLE  CHI 


Suspended  and  Organic  Matters  which  would  be  Contained  in  the  Sewage  Di- 
rectly Tributary  to  the  Several  Divisions  of  the  Harbor  After  Treatment. 
The  Quantities  Given  are  in  Tons  per  12  Lunar  Hours. 


Division  of  the  Harbor 

Year 

Crude 
Sewage 

Screens 

Sewage  Aitei 

Sedimenta- 
tion 

•  Treatment 

Chemical 
Precipitation 

Sprinkling 
Filters 

Sus. 

Org. 

Sus. 

Org. 

Sus. 

Org. 

Sus. 

Org. 

Sus. 

Org. 

/ 

1910 
1940 

52 
111 

70 
148 

44 

94 

63 
153 

21 
44 

49 
104 

7 
16 

8 
6 

35 
74 

5 
11 

2 
1 

21 
44 

1910 
1940 

65 
126 

87 
168 

55 
107 

78 
151 

26 
50 

61 
118 

9 
18 

8 
9 

44 
84 

6 
12 

5 
6 

26 
50 

Upper  East  river  

1910 

12 

16 

10 

14 

5 

11 

1 

8 

8 

1 

2 

5 

1940 

43 

57 

37 

51 

17 

40 

6 

4 

28 

4 

3 

17 

Lower  East  river  

1910 
1940 

133 
209 

178 
279 

113 
178 

160 
251 

53 
84 

125 
195 

20 
31 

0 
4 

89 
140 

13 
20 

3 
9 

53 
84 

1910 

34 

45 

29 

40 

14 

32 

5 

1 

22 

3 

4 

13 

1940 

59 

79 

50 

71 

24 

55 

8 

8 

39 

5 

9 

24 

1910 
1940 

7 
13 

9 
18 

6 
11 

8 
16 

3 
5 

6 
13 

1 

2 

0 
0 

4 
9 

0 
1 

7 
3 

3 
5 

Kill  van  Kull  

1910 

3 

4 

3 

4 

1 

3 

0 

5 

2 

0 

3 

1 

1940 

9 

12 

8 

11 

4 

8 

1 

4 

6 

0 

9 

4 

1910 

23 

30 

20 

27 

9 

21 

3 

4 

15 

2 

3 

9 

 \ 

1940 

59 

79 

50 

71 

24 

55 

8 

8 

40 

5 

9 

24 

Total  

 { 

1910 
1940 

329 
629 

439 
840 

280 
535 

394 
755 

132 
252 

308 
588 

49 
94 

4 

3 

219 
420 

32 
62 

9 
9 

131 
252 

CHAPTER  IV 

TIDAL  CURRENTS  IN  NEW  YORK  HARBOR  AS  SHOWN  BY  FLOATS 

RECORDS  OF  OBSERVATIONS  FROM  1907  TO  1913,  INCLUSIVE 

Observations  of  harbor  currents,  as  shown  by  floats,  were  described  in  the  report  of 
this  commission  dated  April  30,  1910,  Chapter  IV,  page  183,  et  seq.,  and  further  studies 
in  this  direction  were  made  in  1913.  The  object  of  the  new  work  was  to  obtain  knowl- 
edge of  the  currents  in  Lower  New  York  bay,  the  immediate  point  of  interest  being  the 
transporting  effects  to  be  expected  upon  the  discharge  of  sewage  from  the  proposed  out- 
let island  located  about  midway  between  Sandy  Hook  and  Rockaway  Point.  The  site 
of  the  island,  the  main  channels  and  various  lighthouses  and  buoys  mentioned  here  are 
shown  in  Fig.  29. 


FIG.  29 


In  the  report  of  1910,  the  method  of  work  done  up  to  that  time  was  described  and 
the  principal  results  of  the  float  experiments  were  set  forth.  A  large  number  of  float 
observations  which  had  been  made  at  the  time  the  1910  report  was  prepared  could  not 
be  given  in  detail  and  it  has  remained  for  the  present  to  record  these  in  their  proper 
form. 

Scope  of  Work 

There  are  here  described  in  the  form  of  cuts  all  the  float  records  made  by  the  com- 
mission from  1907  to  1913.  Each  cut  is  a  photographic  reproduction  of  a  carefully 
made  outline  map  of  the  part  of  the  harbor  where  the  observations  were  carried  on, 
with  the  path  of  the  float  and  the  essential  data  relating  thereto  plotted  upon  the  map. 


502         DATA  RELATING  TO  THE  PROTECTION  OP  THE  HARBOR 

Method  of  Work  in  1913 
The  observations  were  made  from  a  boat  chartered  for  the  purpose.  This  boat  was 
62  feet  long,  16-foot  beam  and  drew  5  feet  of  water.  Her  tonnage  was  about  40  and  she 
was  propelled  by  a  30-h.p.  steam  engine;  her  speed  averaged  about  8  miles  per  hour. 
The  boat  carried  a  red  flag,  which  proved  an  effective  means  of  warning  off  traffic.  The 
crew  consisted  of  a  captain,  engineer  and  deckhand. 

This  steamer  served  its  purpose  acceptably.  A  large,  open,  forward  deck  covered 
by  an  awning  afforded  a  convenient  place  for  handling  the  floats  and  making  the  obser- 
vations, while  an  unused  galley  under  the  pilot  house  afforded  place  for  storage  of 
instruments  and  equipment  and  permitted  the  setting  up  of  a  drawing  board  where  the 
observations  could  be  plotted.  In  a  heavy  sea  or  ground-swell  the  steamer  rolled  con- 
siderably, a  tendency  which  was  aggravated  when  drifting  near  the  float.  There  were 
comparatively  few  occasions  when  the  sea  was  too  rough  for  operations. 

The  survey  party  consisted  of  two,  and,  at  times,  three  assistants.  Those  engaged 
upon  this  work,  which  was  done  under  the  direction  of  the  President,  were  Ernest  F. 
Robinson,  Herbert  W.  Harvey  and  Homer  Calver.  Their  duty  was  to  follow  the  course 
of  the  float,  guard  it  from  injury  by  passing  vessels,  determine  its  position  at  frequent 


SIDE  ELEVATION  ISOMETRIC 

OF  FLOAT 


FIG.  30 


TIDAL  CURRENTS  IN  NEW  YORK  HARBOR  AS  SHOWN  BY  FLOATS  503 

intervals  and  plot  the  positions  upon  a  standard  chart  of  the  U.  S.  Coast  and  Geodetic 
Survey. 

Floats 

The  typical  float  used  in  the  observations  of  1913  was  similar  to  the  spar  float 
described  in  the  report  of  1910.  It  is  shown  in  Fig.  30.  The  stem  was  a  piece  of  1-inch  by 
1-inch  timber,  G  feet  long,  around  the  upper  end  of  which  was  built  the  float  proper — a 
block  of  wood  12  inches  by  12  inches  by  24  inches.  On  the  lower  end  of  the  stem  were 
4  vanes  21  inches  by  18  inches,  placed  at  right  angle  with  one  another  and  made  of  No. 
14  gauge  sheet  iron.  A  %-inch  rod  for  carrying  a  flag  by  day  or  lanterns  by  night  pro- 
jected about  3!/2  feet  above  the  top  of  the  float ;  it  was  supported  at  its  middle  point  by  a 
frame  of  four  i/s-inch  by  2-inch  flat  bars.  At  the  top  of  this  frame  were  placed  two 
3-inch  rings  for  convenience  in  catching  the  float  when  removing  it  from  the  water. 

This  float,  when  in  use,  was  submerged  so  that  the  top  was  about  even  with  the  sur- 
face of  the  water.  No  effect  was  observable  from  the  wind.  The  flag  and  iron  frame  may 
have  caught  some  wind,  but  not  enough  to  appreciably  affect  the  course  of  the  float. 
When  the  wind  was  very  fresh  the  boat  was  obliged  to  quit  work  on  account  of  the  seas, 
for  which  reason  the  float  was  never  subjected  to  heavy  wind  pressure  such  as  might 
have  altered  its  course.  It  was  noticed  that  floating  objects  which  happened  to  be 
within  view,  such  as  blocks  of  wood,  were  easily  driven  by  the  wind,  as  was  the  steamer, 
while  the  float  often  traveled  in  an  opposite  direction. 

The  flag  carried  by  the  float  was  square,  diagonally  divided  into  red  and  white,  and 
was  plainly  visible  at  distances  of  a  quarter  of  a  mile  or  more.  No  difficulty  was  ever 
experienced  in  finding  the  float.  All  the  observations  were  made  during  daylight  hours. 
The  flags  carried  by  the  float  and  attending  observation  steamer  were  always  scrupu- 
lously respected  by  passing  vessels,  most  of  the  large  ocean  liners  slowing  down  or 
stopping  their  engines  in  passing.  The  number  of  ships  which  showed  the  work  this 
courtesy  was  large,  most  of  the  observations  being  carried  on  in  the  most  frequented 
channel  between  New  York  harbor  and  the  open  ocean. 

None  of  the  floats  approached  the  shore,  or  grounded  or  went  into  inaccessible 
places.  They  were  never  injured  by  vessels  and  throughout  the  work  no  repairs  were 
required  beyond  an  occasional  straightening  of  the  flag  rod  at  the  top,  due  to  accidents 
in  handling. 

Can  floats  were  used  for  a  part  of  the  time  to  determine  the  trend  of  currents  at 
other  depths  than  indicated  by  the  wooden  floats.  The  construction  of  the  can  floats  has 
been  shown  in  the  1910  report  of  the  commission.  Fig.  30,  page  502,  shows  the  design 
and  dimensions  of  both  spar  and  can  floats. 


504         DATA  RELATING  TO  THE  PROTECTION  OP  THE  HARBOR 

The  can  float  was  in  two  parts  connected  by  wire,  whose  length  could  be  regulated 
so  as  to  suit  the  depth  of  water  under  observation.  One  can  floated  at  the  surface  and 
supported  the  other  can.  Each  was  filled  with  sand  and  water  sufficiently  to  be  sub- 
merged. The  can  floats  were  not  found  serviceable  in  the  rough  water  of  Lower  New 
York  bay.  The  choppy  seas  would  raise  and  lower  the  upper  can,  while  the  lower  can 
could  not  accommodate  itself  to  these  sudden  motions.  The  result  was  a  series  of  jerks 
upon  the  connecting  wire  which  tore  out  the  fastenings.  Occasionally  the  can  floats 
grounded  unexpectedly  or  dragged  upon  the  bottom. 

By  watching  for  favorable  opportunities  some  observations  of  interest  were  made 
by  means  of  the  can  floats  in  spite  of  the  shortcomings  which  have  been  mentioned. 

Unsuccessful  Attempts  to  Use  Current  Meters 

Efforts  were  made  to  use  current  meters  to  determine  the  force  and  direction  of 
currents  at  different  depths  at  the  site  of  the  proposed  island  and  elsewhere,  but  this 
undertaking  was  not  successful,  owing,  apparently,  to  the  difficulties  of  insulation 
brought  about  by  salt  water  conditions. 

The  efforts  extended  over  the  period  between  August  18  and  September  3,  1913. 
Two  current  meters  were  obtained  by  loan  through  the  courtesy  of  the  Dock  Department 
of  the  City  of  New  York,  one  being  of  the  Ellis  type  and  the  other  of  the  large  Price 
type.  The  engineers  of  the  Dock  Department  had  been  unable  to  obtain  satisfactory 
results  from  their  use. 

The  meters  were  thoroughly  overhauled  and  some  changes  made  in  their  insulation 
in  order  to  avoid  the  difficulties  anticipated.  Preliminary  to  making  observations,  the 
meters  were  carefully  rated.  For  this  purpose  a  course  of  600  feet  was  laid  off  along 
the  bulkhead  in  Sheepshead  bay  and  ranges  at  right  angles  at  the  ends  and  center  of 
this  course  were  set  up.  The  meters  were  placed  at  the  lower  ends  of  two  vertical  spars, 
one  rigged  over  each  bow  and  far  enough  outboard  to  clear  the  bow  wave.  The  spars 
were  braced  and  guyed  so  as  to  maintain  a  vertical  position  and  keep  the  meters  sub- 
merged about  iy2  feet. 

The  electrical  connections  were  led  inboard  to  a  pair  of  telephone  head  receivers, 
one  for  each  meter,  which  carried  the  grating  sound  of  the  contact  of  each  revolution 
of  the  meter  wheel  to  the  ear  of  the  observer.  The  mirnber  of  revolutions  which 
occurred  at  various  speeds  of  the  boat  when  passing  over  the  measured  course  were 
counted  and  the  time  determined  by  stop-watches.  The  revolutions  of  time  were  reduced 
to  revolutions  per  second  and  the  speed  of  the  boat  reduced  to  feet  per  second.  Upon  a 
sheet  of  cross-section  paper  the  feet  per  second  were  then  plotted  as  abscissas  and  the 
corresponding  revolutions  per  second  as  ordinates.    The  points  plotted  at  the  inter- 


TIDAL  CURRENTS  IN  NEW  YORK  HARBOR  AS  SHOWN  BY  FLOATS  505 

section  of  these  co-ordinates  lay  close  to  a  straight  line.  This  was  the  rating  curve  of 
the  meter. 

It  was  intended  that  the  meters  should  be  observed  by  lowering  them  just  below 
the  surface  of  the  water  in  the  time  taken  for  10  revolutions.  For  bottom  velocities  the 
meter  was  to  be  lowered  to  the  bottom  and  then  raised  a  foot  when  a  second  reading 
was  taken.    Mid-depth  reading  was  also  to  be  obtained. 

Trouble  with  the  insulation  occurred  with  both  meters,  but  the  Price  meter  seemed 
to  be  the  stronger  and  more  serviceable  of  the  two  and  was  more  easily  examined  and 
repaired.  In  the  Ellis  meter  the  trouble  from  insulation  was  due  largely  to  the  fact 
that  sea  water  would  enter  the  contact  chamber,  displacing  the  parafflne  oil  with 
which  it  was  filled,  and  short-circuit  the  meter.  The  entrance  was  effected  around  the 
axle,  where  it  entered  the  contact  box,  there  being  considerable  play  at  this  point.  The 
fine  wire  spring,  upon  which  the  contact  depended,  seemed  subject  to  some  electrolytic 
action  by  which  it  was  eaten  away,  necessitating  frequent  renewals  with  copper  wire. 
In  spite  of  every  effort  which  could  be  made,  this  difficulty  could  not  be  overcome. 
Continual  repairing  was  necessary  and  fully  75  per  cent,  of  the  time  was  occupied  in 
this  work.    It  was  impossible  to  determine  what  observations  were  accurate. 

The  Price  meter  gave  trouble  at  first,  owing  to  faulty  insulation  where  the  wire 
entered  the  contact  chamber.  The  whole  connection  was  finally  covered  bodily  with 
parafflne,  held  in  place  by  rubber  insulating  tape.  The  contact  apparatus  itself  gave 
no  trouble,  when  the  chamber  was  kept  filled  with  parafflne  oil. 

The  chief  difficulty  with  the  Price  meter  occurred  in  the  wire  cable  which  was 
used  to  suspend  the  apparatus  and  carry  the  sound  of  the  revolutions  to  the  observer's 
ear.  The  cable  stretched  and  opened  up  the  insulation.  This  difficulty  might  have  been 
overcome  by  providing  a  different  method  of  suspension,  but  the  prospect  of  further  dif- 
ficulties prevented  this  change  being  made. 

In  all,  five  attempts  were  made  to  secure  observations  for  a  complete  tidal  cycle. 
In  only  one  case,  that  of  August  29,  was  a  record  of  any  considerable  duration  obtained. 
This  extended  from  7:20  A.  M.  to  3:00  P.  m.,  interrupted  by  frequent  breakdowns.  The 
observers  were  uncertain  of  the  results.  Short  circuits,  such  as  were  continually  oc- 
curring, produced  in  the  head  receivers  a  noise  so  closely  resembling  that  of  a  contact 
of  the  meter  that  confusion  resulted.  The  work  was  discontinued  owing  to  the  unrelia- 
bility of  the  results  and  the  probability  that  a  large  amount  of  time  would  necessarily 
be  consumed  in  adjusting  the  meters  to  the  work. 

To  obtain  satisfactory  results  with  current  meters  in  such  work  as  that  contem- 
plated new  instruments  should  be  provided,  preferably  of  large  Price  type.  Suitable 
changes  should  be  made  in  the  insulation  to  fit  them  for  salt  water;  special  cables 


506         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

should  be  provided  for  the  suspensions  and  each  observer  should  be  supplied  with  a  kit 
of  proper  tools  and  equipment  for  making  hasty  repairs  in  the  field. 

Collection  of  Data 

As  far  as  practicable  the  observations  were  begun  just  before  the  beginning  of 
an  ebb  or  flood  current  and  continued  throughout  the  succeeding  flow  of  tide.  As  soon 
as  the  float  was  set  adrift  it  was  located  by  two  sextant  angles  read  from  the  steamer 
to  three  of  the  various  lighthouses  in  the  vicinity  of  the  Lower  bay.  At  intervals  of 
half  an  hour,  or  15  minutes  near  slack  water,  the  steamer  was  run  alongside  the  float 
and  the  location  again  determined,  until  the  final  location  at  the  end  of  the  observa- 
tions, when  the  float  was  taken  up. 

Most  of  the  courses  started  from  the  site  of  the  proposed  outlet  island,  whose  loca- 
tion had  been  fixed  from  soundings  on  the  Coast  Survey  charts.  This  location  was 
determined  in  the  field  by  trial,  reading  sextant  angles  from  various  positions  of  the 
boat  until  when  plotted  they  indicated  the  required  point.  Ranges  were  then  fixed  in 
order  that  the  point  might  readily  be  found  again. 

A  tall  stack  on  Sandy  Hook  was  found  to  be  on  line  with  a  notch  in  the  skyline 
of  Atlantic  Highlands  and,  similarly,  Norton's  Point  was  on  a  line  with  a  break  in 
the  skyline  of  Staten  Island. 

Through  the  courtesy  of  Col.  S.  W.  Roessler,  Corps  of  Engineers,  U.  S.  A.,  a  tripod 
was  located  as  near  the  site  of  the  proposed  island  as  practicable  by  Mr.  G.  E.  Balch, 
U.  S.  Assistant  Engineer  in  charge  of  the  Hydrographic  Survey  of  the  U.  S.  Engineer 
Corps  in  this  vicinity.  On  attempting  to  locate  the  tripod  at  the  site  proposed  it  was 
found  that  the  depth  of  water  was  somewhat  in  excess  of  that  shown  on  the  chart,  so 
that  the  tripod  could  not  conveniently  be  fixed  exactly  in  the  desired  position.  It  was 
finally  placed  about  1,400  feet  southwest  of  the  proposed  site  in  13  feet  of  water  at 
mean  low  tide.  The  Coast  Survey  chart  shows  a  depth  of  10  feet  at  this  point.  The 
tripod  was  constructed  of  4-inch  gas  pipe  and  stood  36  feet  high,  about  half  this  height 
being  submerged. 

The  work  was  directed  from  the  office  in  accordance  with  information  mailed  to 
headquarters  at  the  close  of  each  day's  run.  For  this  purpose  an  approximate  drawing 
of  the  course  last  observed  was  made  upon  a  small  white  print  of  the  Lower  bay  with 
a  scale  of  1  to  80,000  and  sent  by  mail.  This  sheet,  in  addition  to  recording  the  approxi- 
mate path  of  the  float,  contained  such  information  regarding  the  wind  and  weather 
conditions,  hours  of  observation  and  tidal  actions  as  might  be  necessary  for  a  correct 
understanding  of  the  work.  On  those  occasions  when  the  conditions  were  not  favorable 
for  observations  the  observers  reported  at  the  office  for  instructions. 


TIDAL  CURRENTS  IN  NEW  YORK  HARBOR  AS  SHOWN  BY  FLOATS  507 

Plotting  the  Data 

The  path  followed  by  a  float  was  laid  down  upon  charts  traced  from  the  U.  S. 
Coast  and  Geodetic  Survey  charts.  The  observations  of  the  floats  which  were  made  at 
intervals  of  half  an  hour  or  more  frequently  permitted  a  series  of  points  to  be  plotted, 
and  when  these  were  connected  the  path  of  the  float  was  considered  to  have  been  deter- 
mined. 

Two  sextant  angles  had  been  read  in  quick  succession  to  three  prominent  land- 
marks whose  position  was  located  on  the  chart.  In  plotting  the  position  of  the  float, 
the  two  adjacent  angles  were  laid  out  on  a  piece  of  tracing  cloth  and  this  was  shifted 
upon  the  chart  until  the  three  lines  passed  through  the  three  station  points.  The  inter- 
section of  the  angles  was  then  pricked  through  to  the  chart.  The  chart  upon  which  the 
plotting  was  done  had  a  scale  of  1  to  40,000.  Confusion  among  courses  was  avoided  by 
using  a  fresh  chart  after  three  or  four  days'  work. 

The  charts  with  the  paths  of  the  floats  carefully  plotted  thereon  were  delivered  at 
the  commission's  office  and  the  records  were  transferred  to  separate  sheets  for  repro- 
duction. 

There  was  determined  for  each  float  the  total  time  and  distance  traveled,  the 
average  velocity  and  maximum  velocity.  The  most  important  information  was  ob- 
tained from  a  study  of  the  path  itself.  This  was  accepted  as  showing  the  trend  of  the 
main  surface  currents  at  the  times  and  under  the  circumstances  which  occurred.  In 
the  cuts  accompanying  this  report  will  be  found  all  the  essential  data  represented  in 
graphic  form. 

Results 

Twenty-five  spar  float  observations  were  made  in  1913.  They  were  all  made,  en- 
tirely or  in  part,  in  Lower  New  York  bay.  They  were  begun  on  June  9,  1913,  and 
finished  August  25,  1913.  The  total  number  of  hours  worked  was  341.  From  the 
beginning  until  about  June  25  observations  were  made  daily.  Later,  in  order  to  obtain 
longer  records,  two  days'  work  were  concentrated  in  one,  the  work  continuing  through 
a  complete  tidal  cycle  when  the  conditions  permitted.  Interruptions  to  long-continued 
observations  were  frequent  because  of  the  scarcity  of  days  upon  which  three  suc- 
cessive slack  waters  occurred  during  daylight  hours  and  because  of  fog  and  wind  which 
not  infrequently  cut  short  or  prevented  observations  being  made  after  the  party  had 
been  assembled  and  reached  the  point  in  the  boat  from  which  observations  were  to 
begin.  The  longest  series  of  observations  lasted  16  hours.  They  were  on  June  26  and 
July  22.   There  were  10  series  of  observations  continued  for  12  hours  or  more. 

Of  the  25  series  of  observations,  two  were  made  solely  with  a  view  to  determine  the 
time  of  slack  water  at  the  site  of  the  proposed  island  as  compared  with  the  time  of  high 


508         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

and  low  water  at  Sandy  Hook,  and  were  not  productive  of  any  information  as  to  the 
trend  of  the  currents.  Four  others  were  cut  short  by  fog,  heavy  weather  or  other 
unfavorable  conditions;  of  these  3  did  not  progress  far  enough  to  afford  useful  infor- 
mation.  There  were  thus  left  about  20  records  capable  of  affording  useful  data. 

The  most  striking  characteristic  of  the  records,  considered  as  a  whole,  is  the  fact 
that  the  currents  in  the  middle  of  Lower  New  York  bay  run  parallel  to  the  Ambrose 
channel  and  follow  its  turns  at  the  upper  end.  This  fact  is  established  by  a  number  of 
float  records  and  is  controverted  by  none.  Another  salient  characteristic  of  the  float 
paths  is  their  avoidance  of  Jamaica  bay  and  Coney  island  channel.  A  float  carried 
well  into  the  bight  of  Gravesend  bay  on  the  flood  tide  would  return  into  the  main 
channel  and  go  down  Ambrose  channel  instead  of  floating  ashore  on  Coney  island  or 
following  along  the  Coney  island  channel.  This  was  undoubtedly  due  to  the  effect 
of  the  water  in  the  tidal  prism  leaving  Gravesend  bay. 

A  tendency  to  continue  down  the  old  Main  Ship  channel  instead  of  turning  out 
to  sea  through  Ambrose  channel  was  marked  in  some  floats  leaving  the  Narrows.  These 
floats  were  all  halted  by  slack  water  near  West  Bank  or  Romer  Shoals  lighthouses. 
Other  floats  dropped  at  these  points  on  the  first  of  the  flood,  either  turning  north 
toward  the  Narrows  or  went  into  Raritan  bay.  In  the  former  case  they  were  likely 
to  turn  near  Swinburne  or  Hoffman  island  and  go  out  by  Ambrose  channel  or  return 
to  West  Bank  light.  In  the  latter  case,  a  float  would  go  into  Raritan  bay  only  to  Old 
Orchard  light  or  a  little  further  and  return  on  the  next  ebb  current.  One  float  released 
off  Sandy  Hook  at  slack  water  went  almost  due  west  for  about  four  miles  on  the  flood 
current  and  then  returned  to  a  point  near  the  starting  place. 

Floats  which  were  set  adrift  near  Rockaway  inlet  bell  buoy  passed  the  inlet,  show- 
ing no  tendency  to  enter  either  on  the  flood  or  on  the  returning  ebb  current.  Further- 
more, floats  carried  out  to  sea  on  the  ebb  current  in  a  line  parallel  to  Ambrose  channel 
returned  in  the  same  line,  showing  no  tendency  to  move  toward  Rockaway  beach  or 
inlet. 

The  greatest  distances  traveled  from  the  site  of  the  proposed  island  on  the  flood  and 
ebb  currents  respectively  were  to  the  Narrows  and  to  Ambrose  channel  lightship  when 
the  start  was  made  from  the  site  at  slack  water.  A  float  reaching  the  Narrows  and 
returning  parallel  to  Ambrose  channel  was  carried  further  out  than  the  starting  point, 
and  floats  carried  to  sea,  beyond  the  whistling  buoy,  never  reached  the  entrance  to 
Ambrose  channel  on  the  return  flood  tide. 

From  observations  made  with  can  floats  it  appeared  that  the  deeper  currents  trav- 
eled more  slowly  than  the  currents  near  the  surface  and  that  the  currents  at  the  very 
top  of  the  water  moved  more  rapidly  than  any  others.  The  difference  was  least  between 


TIDAL  CURRENTS  IN  NEW  YORK  HARBOR  AS  SHOWN  BY  FLOATS  509 

the  route  follow  ed  by  the  shallow  can  float  and  that  of  the  wooden  spar  float,  the  dif- 
ference amounting  to  150  feet  in  30  minutes.  The  deep  can  float  lagged  behind  the 
wooden  spar  float  between  800  and  1,000  feet  in  the  same  time. 

Conclusions 

Among  the  most  important  inferences  to  be  drawn  from  the  observations  of  spar 
floats  in  the  Lower  New  York  bay  in  the  summer  1913  are  the  following: 

1.  The  shores  of  Lower  New  York  bay  would  be  in  no  danger  of  pollution  if  sew- 
age was  to  be  discharged  at  the  site  of  the  proposed  island. 

2.  On  flood  currents  floating  sewage  would  seldom,  if  ever,  reach  the  Narrows 
and  would  not  pass  into  the  Upper  bay. 

3.  There  is  no  set  of  tidal  water  capable  of  carrying  sewage  from  the  site  of  the 
proposed  island  toward  Rockaway  beach  or  inlet  nor  towards  Coney  island  on  flood 
or  ebb  currents. 

4.  There  is  a  resultant  motion  seaward  from  the  vicinity  of  the  proposed  island 
and  particles  carried  out  to  the  whistling  buoy  or  further  will  not  return. 

5.  Floating  particles  will  be  repelled  from  Gravesend  bay. 

6.  Little  sewage,  if  any,  will  cross  Ambrose  channel,  and  that  which  does  cross 
will  proceed  outward  from  the  Narrows  on  the  ebb  current  and  will  have  a  tendency  to 
return  by  the  same  route. 

7.  The  proportion  of  sewage  from  the  island  which  is  capable  of  reaching  Raritan 
bay  is  small  and  has  no  tendency  to  remain  in  the  bay. 


THE  FLOAT  RECORDS 


HARBOR  CURRENTS  AS  SHOWN  BY  FLOATS 


513 


FLOAT  60,  DEC.  14-16,  1909 

Total  distance,  flood,  =  14.43  miles  in  26.58  hours 

Average  velocity  =  0.54  miles  per  hour 

Maximum    *   =  2.00      *       "  ■ 


FLOAT  15,  AUG.  29,  1908 

Total  distance,  flood,  =2.87  miles  in  2.38  hours 
Average  velocity.  . .  .  =1.21  miles  per  hour 
Maximum  "      ....  —2.55     «       «  « 


FLOAT  64,  DEC.  22-23,  1909 

Total  distance,  flood,  =13.2  miles  in  16.5  hours 
Average  velocity.  . .  .  =0.86  miles  per  hour 
Maximum   '      ....  =2.32     «       «  « 
Total  distance,  ebb,  =8.63  miles  in  14.33  hours 
Average  velocity.  . . .  =0.60  miles  per  hour 
Maximum   "       ....=1.16     ■       «  « 


Paths  of  Floats  in  the  East  River 


514         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


FLOAT  19,  SEPT.  3,  1908 

Total  distance,  flood,  =2.95  miles  in  4.07  hours 
Average  velocity. . .  .  =0.73  miles  per  hour 
Maximum  "      ....=1.61     «       «  « 


FLOAT  17,  SEPT.  1,  1908 

Total  distance,  flood,  =4.14  miles  in  3.8  hours 
Average  velocity. . .  .  =1.09  miles  per  hour 
Maximum  "   =3.60  " 


FLOAT  18,  SEPT.  2,  1908 

Total  distance,  flood,  =4.41  miles  in  4.92  hours 
Average  velocity.  .  .  .  =0.9   miles  per  hour 
Maximum   "      ....  =1.93     u       a  a 


Paths  of  Floats  in  the  East  River 


HARBOR  CURRENTS  AS  SHOWN  BY  FLOATS 


515 


FLOAT  63,  DEC.  21,  1909 

Total  distance,  flood,  =7.26  miles  in  6.0  hours 
Average  velocity.  .  . .  =1.46  miles  per  hour 
Maximum  "      ....  =2.36     ■       «  « 
Total  distance,  ebb,  =6.00  miles  in  6.17  hours 
Average  velocity. . . .  =0.97  miles  per  hour 
Maximum  ■   =2.23     *       *  * 


FLOAT  62,  DEC.  20-21,  1909 

Total  distance,  flood,  =5.40  miles  in  7.33  hours 
Average  velocity.  . .  .  =0.74  miles  per  hour 
Maximum  *      ....  =1.62     «       »  ■ 
Total  distance,  ebb,  =4.0   miles  in  5. 75  hours 
Average  velocity. . .  .  =0.70  miles  per  hour 
Maximum  "   =0.97  * 


FLOAT  53,  NOV.  22-23,  1909 

Total  distance,  flood,  =3.21  miles  in  5.67  hours 
Average  velocity. .  .  .  =1.45  miles  per  hour 
Maximum  "      ....  =4.12 

Total  distance,  ebb,  =6.31  miles  in  6.87  hours 
Average  velocity..  .  .  =0.92  miles  per  hour 
Maximum  '   =2.65  * 


FLOAT  25,  SEPT.  10,  1908 

Total  distance,  ebb,  =6.85  miles  in  E.80  hours 
Average  velocity ...   =1.18  miles  per  hour 
Maximum   ■      ....=1.98     ■      »  ■ 


Paths  of  Floats  in  the  East  River 


516         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


Paths  of  Floats  in  the  East  River 


HARBOR  CURRENTS 


AS  SHOWN  BY  FLOATS 


517 


FLOAT  23,  SEPT.  8,  1908 

Total  distance,  flood,  =2.25  miles  in  2.25  hours 
Average  velocity.. . .  =1.0   mile  per  hour 
Maximum  "      ....=1.8   miles    "  " 
Ebb,  maximum  ve- 
locity =6.5       «       «  « 


FLOAT  38 

Total  distance,  flood,  =  8.80  miles  in  5.92  hours 
Average  velocity.  . . .  =  1.49  miles  per  hour 
Maximum   "      .  .  .  .  =  7.20     "       *  " 
Total  distance,  ebb,  =11.05  miles  in  5.7  hours 
Average  velocity. . .  .  =  1.94  miles  per  hour 
Maximum  "      . . .  .  =  6.70     «       «  « 


FLOAT  38,  OCT.  3,  1908 


Paths  of  Floats  in  the  East  River  and  Upper  Bay 


518 


DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


Paths  of  Floats  in  the  East  River  and  Upper  Bay 


HAEBOR  CURRENTS  AS  SHOWN  BY  FLOATS 


519 


SOLE  OF  MILES  7 


FLOAT  39,  OCT.  5,  1908 

Udxircura  velocity,  3ood,  =3.97  miles  per  hour 


FLOAT  F,  MAR.  7,  1907 

Total  distance,  flood,  =8.0   miles  in  4.78  hours 
Average  velocity. . . .  =1.67  miles  per  hour 
Maximum  "      ....  =2.5      «       «  « 


Paths  of  Floats  in  the  East  River  and  Upper  Bay 


520         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


FLOAT  22,  SEPT.  5,  1908 

Total  distance,  flood,  =0.77  miles  in  4.01  hours 
Average  velocity. . . .  =0.19  miles  per  hour 
Maximum  "      ....  =0.33     *       "  " 


Paths  of  Floats  in  the  East  River  and  Upper  Bay 


HARBOR  CURRENTS  AS  SHOWN  BY  FLOATS 


521 


FLOAT  36,  SEPT.  30.  1908 


FLOAT  9,  AUG.  11,  1908 

Total  distance,  flood,  =0.74  miles  in  3.12  hours 
Average  velocity.  .  .  .  =0.24  miles  per  hour 
Maximum  "      ....  =1.24     "       *  " 
Total  distance,  ebb,  =0.74  miles  in  3.03  hours 
Average  velocity. . . .  =0.24  miles  per  hour 
Maximum   "      ....  =0.87     "  " 


FLOAT  6,  AUG.  18,  1908 

Total  distance,  flood,  =2.75  miles  in  6.52  hours 
Average  velocity. .  .  .  =0.42  miles  per  hour 
Maximum   "      ....  =0.77     •       «  ■ 
Total  distance,  ebb,  =0.84  miles  in  1.47  hours 
Average  velocity.  .  . .  =0.57  miles  per  hour 
Maximum  "      ....  =1.33     «       «  « 


FLOAT  8,  AUG.  20,  1908 
Total  distance,  ebb,  =1.67  miles  in  2.15  hours 
Average  velocity ....  =0.78  miles  per  hour 
Maximum  "      ....=1.38     «       «  ■ 
Flood,  maximum  ve- 
locity =2.00  ' 


Paths  of  Floats  in  the  Harlem  River 


522 


DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


HARBOR  CURRENTS  AS 


SHOWN  BY  FLOATS 


523 





j  'i.j  1:54 
■JS. 


ft* 


4 


o 


FLOAT  12,  AUG.  26,  1908 

Total  distance,  ebb,  =6.45  miles  in  4.18  hours 
Average  velocity ....  =1.54  miles  per  hour 
Maximum  *   =2.52     1       ■  ■ 


Hudson  River 


■MB  1^56 
M.E.  STRQ1G 


SCALE  OF  FECT 


1 :56  P.M.  Float  disappeared  in  eddy. 
Thi=  was  the  4th  time  float  had  been 
sacked  down  out  of  sight  in  eddy, 
_    '  but  previously  it  had  reappeared.  This 

time  it  failed  to  return  to  the  sarface. 




FLOAT  12A,  AUG.  2G,  190S 


FLOAT  2,  AUG.  15,  1908 

Total  distance,  flood,  =0.4   miles  in  2.3  hours 
Average  velocity. . . .  =0.17  miles  per  hour 
Maximum  *      ....  =0.32     «      «  ■ 
Total  distance,  ebb,  =0.31  miles  in  1.45  hours 
Average  velocity.  .  .  .  =0.21  miles  per  hour 
Maximum  *      ....  =0.41     "       *  * 


Paths  of  Floats  in  the  Harlem  River 


524  DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


HARBOR  CURRENTS  AS  SHOWN  BY  FLOATS 


525 


FLOAT  M,  APRIL  2,  1907 


Paths  of  Floats  in  the  Hudson  River 


526  DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


FLOAT  46,  NOV.  8-9,  1909 

Total  distance,  ebb,  =16.78  miles  in  9.83  hours 
Average  velocity.   .  =  1.71  miles  per  hour 
Maximum   "      .  .  .  =  4.2       *       *  " 


Paths  of  Floats  in  the  Hudson  River 


HARBOR  CURRENTS  AS  SHOWN  BY  FLOATS 


527 


528  DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


■■i  -*- 

mm 


FUOAT  TAKEN  UP 


^i.v,^.W"»«  

i 


Jisslfltice  covered  hy  float  =1%  mil 
\I;:\.mutu  |'elocity=!£  miles  per  hour.         '-.  : 
SI  i.  K  ».ii(A-at  12  10  p.m. 


in  >'/  his, 





FLOAT  V,  JULY  11,  1907 
Average  velocity,  ebb,  =0.9  miles  per  hour 


FLOAT  37,  OCT.  1,  1908 
Maximum  velocity,  flood, — 3.0  miles  per  hour 


FLOAT  1,  AUG.  14,  1908 
Maximum  velocity,  ebb,  =3.07  miles  per  hour 


Paths  of  Floats  in  the  Hudson  River  and  Upper  Bay 


HARBOR  CURRENTS  AS  SHOWN  BY  FLOATS 


529 


530  DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


Upper 

Robblns  Reef 
jiO  miles  ]  |    *  Light 

Bay 


SlOOfc  GI10P.M 

FLOAT  TAKEN  \J^ 


Bay 

'Total  distance  covered  "Il^f  miles  inohrs.  25  min. 
'/  at  2  miles  per  hour.-Float  ashore  twice  however 
Muximuni  velocity  =  3  mileB  per  hour. 


FLOAT  19,  SEPT.  3,  1908 


SCALE  Of  MILES 


FLOAT  0,  APRIL  8,  1907 
Average  velocity,  flood,  =1.02  miles  per  hour 


FLOAT  56,  DEC.  1-4,  1909 

Total  distance,  flood,  =20.62  miles  in  26.12  hours 
Average  velocity . . .  .  =  0.82  miles  per  hour 
Maximum  "      ....  =  1.30     "       *  " 
Total  distance,  ebb,  =44.9   miles  in  38.8  hours 
Average  velocity. .. .  =  1.16  miles  per  hour 
Maximum  "      .,..=  4.05     «      «  « 


Paths  of  Floats  in  Newark  Bay  and  Kill  Van  Kull 


532 


DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


FLOAT  H,  MAR.  23,  1907 
Average  velocity,  flood,  =0  68  miles  per  hour 


FLOAT  K,  MAR.  28,  1907 


Paths  of  Floats  in  the  Upper  Bay 


HARBOR  CURRENTS  AS  SHOWN  BY  FLOATS 


533 


Paths  of  Floats  in  the  Upper  Bay 


534  DATA  RELATING  TO  THE  PROTECTION  OE  THE  HARBOR 


Total  distance  covered  by  float  =  2.00  miles 
from  8:08  a.m.  to  10:2G  a.m.  =  2  hours  18  mins. 


FLOAT  26,  SEPT.  11,  1908 

Average  velocity,  flood,  =1.26  miles  per  hour 
Maximum   "  «     =1.94     "  " 


 SCALE  OF  MILES 

1       '    '  0  1  2  3 


FLOAT  68,  DEC.  9-10,  1909 

Total  distance,  flood,  =10.6   miles  in  9.17  hours 
Average  velocity. . . .  =  1.16  miles  per  hour 
Maximum  "      .  .  .  .  =  3.64     "       "  " 
Total  distance,  ebb,  =17.18  miles  in  13.5  hours 
Average  velocity. . . .  =  1.27  miles  per  hour 
Maximum  "      . . . .  =  8.4      "       ■  " 


Paths  of  Floats  in  the  Upper  Bay 


HAEBOR  CURRENTS  AS  SHOWN  BY  FLOATS 


535 


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536  DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


U  p  p  e   r  n1"0 


.  iriburne  Hosp.  I,  ^ 

Total  distance  covered  on  ebb 
Average  velocity  during  ebb 
Maximum  velocity  during  ebb 
H.W.G.I. 
L.W.G.I. 

SCALE  OF  MILES 


7.53  mi. 
1.37  mi.per  hr. 
3.11  mi.per  br. 
7.33  A.M. 
2.00  P.M. 

Note:  Diat.  that  woulj  have  boon  eoversd 
from  2.21  to  3.00  P.M.  esfd  at  0.70  ail. 


FLOAT  32,  SEPT.  26,  1908 


Robblnt  Reef  it 
L.  H. 


Upper 


Bay 


wind  w.n 
moderate]  tfl^,„a 


6CALE  OF  VILES 


FLOAT  30,  SEPT.  18,  1908 

Total  distance,  flood,  =1.2   miles  in  2.63  hours 
Average  velocity. . . .  =0.46  miles  per  hour 
Maximum  "      ....=1.03     "      "  ° 
Total  distance,  ebb,  =2.23  miles  in  3.08  hours 
Average  velocity. . . .  =0.72  miles  per  hour 
Maximum  "   =2.25  " 


Paths  of  Floats  in  the  Upper  Bay 


HARBOR  CURRENTS  AS 


SHOWN  BY  FLOATS 


537 


FLOAT  65,  NOV.  29-30,  1909 

Total  distance,  flood,  =10.71  miles  in  10.27  hours 
Average  velocity...  .  =  1.04  miles  per  hour 
Maximum   "       . ...  =  2.4       "       "  " 
Total  distance,  ebb,  =33.44  miles  in  20.16  hours 
Average  velocity  . .. .  =  1.66  miles  per  hour 
Maximum  "      ....  =  6.7      "       "  " 


Total  distance  covered  from  7:15  td 
=  10.30  A.M-5X  miles  in  2  hrs.  45  min. 

at  1.9  miles  per  hour   SCALE  OF  MILES 

Maximum  velocity  =  2J^  miles  per  hour         q  J 


FLOAT  S,  APRIL  13,  1907 


FLOAT  I,  MAR.  26,  1907 

Total  distance,  flood,  =  1.76  miles  in  2.42  hours 
Average  velocity. .  . .  =0.72  miles  per  hour 
Maximum  "      ....=1.25     «       «  « 


Paths  of  Floats  in  the  Upper  and  Lower  Bays 


538 


DATA  DELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


f^.The  Narrotoa  « 


Swinburne 
Hospital  I. 


FLOAT  21,  SEPT.  4,  1908 

Total  distance,  ebb,  =2.37  miles  in  1.98  hours 
Average  velocity  ....  =1.2   miles  per  hour 
Maximum  "      ....  =1.75     «       «  « 


SCALE  OF  f.'lLES 


1  %  V, 


14l 

gas  BUOV^y 

U  ,'p  P 


10-.J0  FLOAT  STARTED 


DobUns  Reef  & V\ 
Light  I  1* 


J* 
\^»-Y*\»0  float  taken  up 

Total  distance  covered  by  float- 11 X  iuDmJb  G 1  j  hours  at 
no  average  volocltj  of  15^  mllo*  per  bour. 
Mrtxliauta  nlMfljfSW  mild  per  l>«nr  just  soutb  of  Sorrows 
Start  noar  beginning  a  ebb  tide.    (  #  Shoal  it. 

At  6  P.M.,  buoy  J  In  main  chin  nil  "turned  Up" 


L  O  10  £  f 
Homer  Light  ^ 


9:30  A.M. 
JUNE  17, ion 
FLC*T  81AK1C0 


WtNO  N.W.  i 
8  MILES  * 


(Ji  Site  of  Island 


WIND  10:30  A.M.  ( 
N.W.  1  MILE  % 


t  I 


Scotland 
A*  Light-ship 


Jtookaway 
Inlet 


ROCKAWAY  i 
POINT  t 


tf  2:00  P.M. 
FLOAT  TAKEN  UP 
TCO  HAZY  FOR 
OBSERVATIONS 


[NO  WINOl 


SCALE  OF  MILES 


Ambrose  Channel 
if.  Light-ship 


FLOAT  70,  JUNE  17,  1913 
Total  distance,  ebb,  =4.13  miles  in  6.0  hours 
Average  velocity...  =0.83  miles  per  hour 
Maximum  "      ...  =1.17  " 


FLOAT  U,  JULY  8,  1907 


FLOAT  82,  JULY  16,  1913 

Total  distance,  Hood,  =2.8-1  miles  in  5.93  hours 
Average  velocity.  .  . .  =0.48  miles  per  hour 
Maximum  "      ....  =0.63     *      *  * 
Total  distance,  ebb,  =6.0   miles  in  6.07  hours 
Average  velocity.  .  . .  =0.99  miles  per  hour 
Maximum  ■      ....  =1.62     "       1  " 


Paths  of  Floats  in  the  Lower  Bay 


HARBOR  CURRENTS  AS  SHOWN  BY  FLOATS 


539 


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540 


DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


FLOAT  81,  JULY  14,  1913 

Total  distance,  flood,  =2.78  miles  in  6.23  hours 
Average  velocity.  . . .  =0.45  miles  per  hour 
Maximum  "      ....  =0.71     "       "  " 
Total  distance,  ebb,  =  8.S4  miles  in  6.63  hours 
Average  velocity.  . .  .  =1.26  miles  per  hour 
Maximum  "      ....  =2.08     «       «  « 


FLOAT  77,  JUNE  27,  1913 

Total  distance,  flood,  =4.42  miles  in  7.47  hours 
Average  velocity. .  . .  =0.69  miles  per  hour 
Maximum  "      ....  =0.82     «       «  « 
Total  distance,  ebb,  =3.42  miles  in  3  42  hours 
Average  velocity. ...  =1.0   miles  per  hour 
Maximum  "      ....  =1.16     "      ■  " 


JUNE  16,  10:01  A.M 
FLOAT  6TARTCD 


2:00  P.M. 
(FLOAT  TAKEN  UP 

1-12:30 


12:01  P.M,^^2^12:53 

1 :23 


0 

6CALE  OF  MILES 


bANQV  HOOK 


1 — I  1  1  r- 

0      H  l 


-r 


FLOAT  69,  JUNE  16,  1913 

Total  distance,  ebb,  =2.37  miles  in  3.45  hours 
Average  velocity....  =0.69  miles  per  hour 
Maximum  "      ....=1.26     "       "  * 


FLOAT  76,  JUNE  24,  1913 

Total  distance,  flood,  =2.84  miles  in  3.3S  hours 
Average  velocity. . . .  =0.85  miles  per  hour 
Maximum  "      ....  =0.95     «       «  « 
Total  distance,  ebb,  =2.84  miles  in  3.0  hours 
Average  velocity. . .  .  =0.95  miles  per  hour 
Maximum  "   -1.46     -       «  ■ 


Paths  of  Floats  in  the  Lower  Bay 


FLOAT  72,  JUNE  19,  1913 

Total  distance,  ebb,  =2.84  miles  in  2.8  hours 
Average  velocity.  . .  .  =1.02  miles  per  hour 
Maximum   "      ....=1.51     "       *  * 


FLOAT  74,  JUNE  23,  1913 

Total  distance,  flood,  =0.32  miles  in  0.62  hours 
Average  velocity. .  .  .  =0.52  miles  per  hour 
Maximum   "      ....  =0.62     ■       «  « 
Total  distance,  ebb,  =1.70  miles  in  1.97  hours 
Average  velocity.  . . .  =0.86  miles  per  hour 
Maximum   "      ....  =1.23     "       "  " 


FLOAT  83,  JULY  22,  1913 

Total  distance,  flood,  =6.60  miles  in  6.98  hours 
Average  velocity.  .  .  .  =0.95  miles  per  hour 
Maximum   "      ....  =1.47     «       «  « 
Total  distance,  ebb,  =4.74  miles  in  6.52  hours 
Average  velocity.  .  .  .  =0.86  miles  per  hour 
Maximum  "      ....=1.19     "       "  " 


K  L  Y  N 


to 


9:i9VfcES£T 
NO  WIND 

Site  of  island 
7:45  d> 

FLOAT  STARTED 
WIND  S,  .  I 
4  MILES  ^| 


V 


n — i — 


SCALE  OF  MILES 


SANDY  HOOK 


Site  of  Islard 
Romer  Light 

■k 


SCALE  OF  MILES 


SANDY  HOOK 


2:52  P.  M. 
FLOAT  TAKEN  UP 
jwiND  S.E.W  I       &  Romer  Light 

| 35  WILES  ^[  -fr 


Site  of  Island  (J) 


V 


6CALE  OF  MILES 


2  3 
SANDY  HOOK 


FLOAT  84,  JULY  24,  1913 

Total  distance,  flood,  =4.74  miles  in  5.70  hours 
Average  velocity. . . .  =0.83  miles  per  hour 
Maximum  "   =1.52  « 


FLOAT  87,  JULY  30,  1913 

Total  distance,  flood,  =8.62  miles  in  8.25  hours 
Average  velocity.  . .  .  =1.03  miles  per  hour 
Maximum   "      ....=1.63     "       "  " 
Total  distance,  ebb,  =4.61  miles  in  4.1  hours 
Average  velocity. . . .  =1.13  miles  per  hour 
Maximum   "      ....=1.20    "        «  « 


FLOAT  88,  AUG.  1,  1913 

Total  distance,  flood,  =1.33  miles  in  1.35  hours 
Average  velocity. .  .  .  =0.99  miles  per  hour 
Maximum   "      ....=0.99     •       «  « 
Total  distance,  ebb,  =5.93  miles  in  6.26  houcs 
Average  velocity.  .  .  .  =1.13  miles  per  hour 
Maximum   "      ....=1.69   "        «  « 


Paths  of  Floats  in  the  Lower  Bay 


542 


DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


v 


SCALE  OF  MILES 

— i  r~ 


SANDY  HOOK 


FLOAT  73,  JUNE  20,  1913 

Total  distance,  ebb,  =7.15  miles  in  6.17  hours 
Average  velocity.  . . .  =1.44  miles  per  hour 
Maximum  "      ....  =2.03     «       «  « 


SCALE  OF  MILES 


SANDY  HOOK 


FLOAT  67,  JUNE  11,  1913 

Total  distance,  flood,  =4.86  miles  in  4.92  hours 
Average  velocity.  . .  .  =0.99  miles  per  hour 
Maximum  "      ....  =1.14     «       «  « 
Total  distance,  ebb,  =1.32  miles  in  1.5  hours 
Average  velocity. . . .  =0.88  miles  per  hour 
Maximum  "      ....  =1.36     «       «  « 


FLOAT  78,  JULY  1,  1913 

Total  distance,  flood,  =0.76  miles  in  0.97  hours 
Average  velocity. . . .  =0.78  miles  per  hour 
Maximum  "      ....=1.05     «       «  « 
Total  distance,  ebb,  =3.03  miles  in  2.97  hours 
Average  velocity.  . . .  =1.02  miles  per  hour 
Maximum  "      ....=1.77     "       "  " 


FLOAT  79,  JULY  3,  1913 

Total  distance,  flood,  =0.79  miles  in  1.0  hour 
Average  velocity ....  =0.79  miles  per  hour 
Maximum  "      ....  =1.12     «       «  ■ 
Total  distance,  ebb,  =1.89  miles  in  2.5  hours 
Average  velocity. .. .  =0.76  miles  per  hour 
Maximum  "      ....=1.20     •       «  « 


Paths  of  Floats  in  the  Lower  Bay 


HARBOR  CURRENTS  AS  SHOWN  BY  FLOATS 


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544         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


CHAPTER  V 


TIDAL  INFORMATION  IN  POSSESSION  OF  THE  COMMISSION  AND 
CORRESPONDENCE  ON  THIS  SUBJECT  WITH  THE  UNITED 
STATES  COAST  AND  GEODETIC  SURVEY 

TIDAL  STUDIES 

In  the  Commission's  first  report,  issued  in  April,  1910,  considerable  space  was 
given  to  a  discussion  of  the  tidal  phenomena  in  the  metropolitan  district,  and  this 
information  was  considered  to  have  value  not  only  in  the  disposal  of  the  sewage,  but 
to  shipping  and  other  interests. 

Owing  to  the  fact  that  the  methods  of  calculation  employed  have  never  been  fully 
explained,  in  view  of  some  corrections  which  have  had  to  be  made  in  the  published 
records  of  the  Commission  and  because  of  the  importance  which  properly  attaches 
to  the  information,  it  seems  desirable  here  briefly  to  make  such  explanations  and  cor- 
rections as  may  be  necessary  in  order  to  reconcile  the  data  and  to  explain  how  some  of 
the  most  important  particulars  were  derived. 

The  principal  and  hydrographic  features  of  the  harbor  were  discussed  in  the 
1910  report  together  with  the  principal  current  phenomena  and  the  phenomena  of  dis- 
charge. Attention  was  given  to  the  flow  of  land  and  sea  water  entering  the  harbor, 
the  volumes  of  water  in  the  harbor,  and  the  tidal  ranges.  Finally,  included  in  this 
discussion,  reference  was  made  to  the  effects  of  winds,  dredgings,  obstructions  and 
bulkheads  upon  the  tidal  flow.  This  information  is  contained  in  the  Report  of  April, 
1910,  Part  III,  Chapter  III. 

Supplementing  the  discussion  of  the  tidal  phenomena,  the  report  of  1910  contains 
a  chapter  on  the  harbor  currents  as  shown  by  floats.  The  float  work  included  a  con- 
siderable number  of  observations  of  can  and  spar  floats  which  were  set  adrift  and 
observed  for  long  periods  of  time,  occasionally  for  several  days,  in  various  parts  of 
the  harbor.  The  information  in  regard  to  this  float  work  is  contained  in  Part  III, 
Chapter  IV  of  the  Report  of  April,  1910. 

During  the  course  of  a  full  year,  observations  of  the  salinity  of  the  waters  were 
made  at  eleven  stations  in  the  harbor,  the  object  being  to  supplement  the  informa- 
tion obtained  from  other  sources  as  to  the  tidal  phenomena  and  indicate  the  changes 
in  the  proportions  of  sea  and  land  water  present  at  different  tides  and  seasons  at 
widely  separated  points.  For  the  purposes  of  this  work  a  special  apparatus  was  de- 
vised and  a  large  number  of  observations  made.  The  results  were  published  in  the 
report  of  1910,  Part  III,  Chapter  XIII.  The  proportions  of  land  water  and  sea  water 
are  indicated  by  means  of  tables  and  a  diagram.  The  original  observations  were  too 
voluminous  for  publication. 


546         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

Hydrographic  information  in  addition  to  that  published  in  the  1910  report  has 
been  issued  by  the  Commission  in  its  report  of  August,  1912,  and  in  some  of  its 
preliminary  reports.  The  divisions  of  the  harbor  with  their  areas  were  given  in  the 
1912  report  together  with  a  discussion  of  the  volumes  and  circulation  of  the  water. 
(See  Part  I,  Chapter  II.) 

The  volumes  of  water  in  the  several  divisions  during  low  tide,  the  water  in  the 
tidal  prism  and  the  resultant  ebb  flow  were  stated  in  Preliminary  Report  VI,  issued 
February,  1913. 

In  Chapter  IV,  Part  IV  of  this  report,  there  is  a  description  of  the  tidal  currents 
in  the  harbor  as  shown  by  the  float  records  which  the  Commission  considers  sufficiently 
reliable  to  be  used  as  a  basis  for  calculations. 

Explanation  of  Methods  Employed 

Tidal  Volumes. — The  tidal  volumes  as  published  in  the  Commission's  1910  report, 
and  subsequently,  are  based  upon  a  theoretical  investigation  made  by  the  U.  S.  Coast 
and  Geodetic  Survey  in  response  to  the  Commission's  request.  The  results  are  con- 
tained in  a  letter  from  the  Survey  to  the  Commission  dated  August  14,  1908. 

The  method  of  computation  consisted  of  first  determining  the  mean  cross- 
sectional  area  of  the  tidal  channel  under  consideration,  and  then  correcting  to  mean 
conditions  the  average  of  the  maximum  observed  velocities  for  flood  and  ebb 
currents  in  this  section  according  to  the  ratio  which  the  tidal  range  during  the  ob- 
servations bore  to  the  mean  range.  If  the  flow  is  hydraulic,  due  to  difference  of 
head  (as  between  Long  Island  sound  and  the  Upper  bay)  instead  of  to  progressive 
wave  action,  the  correction  is  made  according  to  the  ratio  of  the  square  roots  of  the 
respective  ranges.  To  this  velocity  is  then  applied  a  factor  (about  0.75)  reducing  the 
maximum  velocity  to  the  mean  in  the  section  at  the  strength  of  the  current ;  a  second 
factor,  — ,  is  then  applied,  reducing  the  velocity  at  the  strength  of  current  to  the 
mean  velocity  for  the  duration  of  flow  (this  upon  the  assumption  that  the  velocity 
curve  is  a  true  sine  curve).  Finally,  the  product  of  this  velocity  by  the  cross-sectional 
area  by  the  number  of  seconds  in  six  lunar  hours  gives  the  average  volume  of  the  flood 
or  ebb  flow. 

If  there  is  an  ebb  excess,  half  this  amount  is  deducted  from  and  half  added  to  the 
volume  as  above  computed,  to  obtain  the  flood  and  ebb  volumes,  respectively.  The  ebb 
excess  of  the  Hudson  and  Kill  van  Kull  is  due  to  land  water  discharge,  which  quantity 
is  obtained  from  rainfall  records.  The  ebb  excesses  of  the  East  river  and  Harlem 
river  are  chiefly  due  to  hydraulic  conditions.  The  ebb  excess  of  the  Narrows  is  the 
total  land  water  discharge  and  the  excess  of  the  East  river. 

In  recalculating  the  results  the  Survey's  method  was  slightly  modified  by  the 
Commission  in  that  flood  and  ebb  volumes  were  computed  separately,  the  actual  dura- 
tions of  the  flood  and  ebb  currents  were  used,  and  an  attempt  was  made,  from  records 


METHODS  EMPLOYED 


547 


of  previous  observations,  to  obtain  a  reliable  factor  for  reducing  the  maximum 
velocity  in  a  cross-section  to  the  mean.  The  modified  method,  while  an  improvement 
upon  that  described  before,  is  still  faulty,  in  that  the  reduction  factor  is  sometimes 
based  upon  meagre  information  and  is  constant,  whereas  observations  of  the  U.  S. 
Engineers  in  Hell  Gate  and  vicinity  indicate  that  this  factor  changes  continually 
during  each  current. 

The  tidal  volumes  computed  in  this  manner  were  published  in  the  Commission's 
report  of  April  30,  1910,  page  178,  and  again  in  the  report  of  August  1,  1912,  and  in 
the  absence  of  reliable  gaugings,  they  must  be  regarded  as  representing  the  most 
authentic  information  available. 

The  areas  at  mean  low  water  of  the  various  divisions  of  the  harbor  were  com- 
puted in  the  office  of  the  Commission  from  the  Coast  Survey  charts.  Each  area  was 
carefully  measured  by  a  planimeter,  and  was  taken  as  the  mean  of  several  readings. 
Care  was  taken  to  use  the  actual,  instead  of  the  nominal  scale  of  the  charts,  the  cor- 
rection factor  being  the  ratio  between  the  measured  length  of  the  engraved  linear 
scale  and  its  nominal  length  as  computed  by  the  representative  fraction.  The  fig- 
ures thus  obtained  were  published  in  the  report  of  April  30,  1910.  Before  the  publi- 
cation of  the  1912  report,  however,  it  was  discovered  that  the  former  measurements 
had  been  taken  to  the  high  water  contour  instead  of  to  that  of  low  water.  The  areas 
were  therefore  recomputed  and  published,  August  1,  1912. 

The  tidal  prism  is  the  volume  of  water  normally  lying  above  the  plane  of  mean 
low  water  and  high  tide.  It  is  equal  to  the  product  of  the  area  at  mean  tide  level  by 
the  mean  range  of  tide.  For  the  various  divisions  of  the  harbor,  the  tidal  prism  was 
computed  in  the  office  of  the  Commission,  using  the  mean  range  of  tide  as  given  by 
the  Coast  Survey,  and  an  average  of  the  areas  at  mean  low  water  and  mean  high 
water.  In  some  parts  of  the  harbor,  such  as  the  Upper  East  river,  Harlem  river, 
and  Jamaica  bay  the  difference  between  these  areas  is  great,  while  in  the  lower 
East  river,  Hudson  river,  Upper  bay,  Kill  van  Kull  and  Arthur  Kill,  it  is  almost 
negligible,  and  the  tidal  prism  may  be  taken  as  the  product  of  the  mean  low  water 
area  by  the  mean  range  of  tide.  In  Newark  bay  the  difference  is  appreciable,  but  not 
great. 

The  volume  below  mean  low  water  was  originally  computed  by  the  Commission 
by  two  methods.  For  the  large,  open  bodies  of  water  such  as  the  Upper  bay,  the  sur- 
face of  the  chart  was  divided  into  small  squares,  and  from  the  soundings  the  average 
depth  and  volume  were  obtained  for  each  square.  For  the  river  channels,  cross-sec- 
tions were  taken  at  regular  intervals  upon  the  chart,  their  areas  determined,  and  the 
intervening  volume  found  by  average  end  areas. 

In  the  original  computations  of  the  Commission,  the  East  river  was  considered 
in  three  sections,  divided  at  88th  Street  and  at  Old  Ferry  Point.  Data  for  the  East 
river,  arranged  for  this  division,  was  published  in  the  report  of  April  30,  1910. 


548         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


Before  the  publication  of  the  report  of  1912  the  classification  was  changed,  and 
in  this  report  the  data  is  tabulated  for  the  Upper  and  the  Lower  East  river,  two  divi- 
sions only,  divided  at  88th  Street.  More  recently  the  line  of  division  has  been  con- 
sidered as  located  at  Lawrence  Point,  necessitating  a  recomputation  of  data. 

A  new  method  was  employed  for  determining  the  volume  below  mean  low  water. 
The  area  of  each  contour,  from  that  of  mean  low  water  to  the  greatest  depth,  was 
measured  by  a  planimeter,  two  sets  of  measurements  being  taken  to  insure  accuracy. 
The  contour  interval  assumed  was  six  feet  for  the  first  sixty  feet  of  depth,  and  ten 
feet  for  greater  depths.  These  areas  were  then  combined  by  the  prismoid  formula 
to  determine  the  volume. 

The  summation  of  volumes  for  the  total  East  river  were  at  variance  with  former 
estimates  and  it  was  deemed  advisable  to  revise  the  computations  of  other  divisions 
in  which  the  dilution  factor  was  of  importance.  Consequently  the  volume,  tidal 
prism,  etc.,  of  Jamaica  bay  and  the  Harlem  river  were  recomputed,  and  results  vary- 
ing from  previous  determinations  were  obtained.  These  revised  figures  were  pub- 
lished in  Preliminary  Report  No.  VI,  Metropolitan  Sewerage  Commission,  February, 
1913. 

The  average  depth  is  the  quotient  of  the  volume  below  mean  low  water  divided 
by  the  mean  low  water  area. 

The  complete  tidal  data  in  possession  of  the  Commission,  as  corrected  to  the 
latest  information,  and  as  used  in  the  latest  computations,  is  given  in  a  table  at- 
tached to  this  report.  All  these  data  have,  at  one  time  or  another,  appeared  in  the 
publications  of  the  Commission. 

The  values  given  for  the  mean  low  water  area,  tidal  prism,  and  volume  below 
mean  low  water  are  the  result  of  careful  measurements  and  computations  from  the 
Coast  Survey  Charts. 


TABLE  CIV 


Division 

Area 
M.L.W. 
square 

miles 

Aver- 
age 
tidal 
range, 
feet 

Tidal 
prism, 
million 
cubic 
feet 

Aver- 
age 

depth, 
feet 

Volume 
below 

M.L.W. 

million 
cubic 
feet 

Section 

Ebb 
volume, 
million 

cubic 

feet 

Flood 
volume, 
million 

cubic 
feet 

Ebb 

excess, 
million 
cubic 
feet 

1.  Upper  bay  

19.51 

4.4 

2,541 

23.9 

12,970 

Narrows 

12,773 

11,490 

1,283 

2.  Hudson  river  (below  Mt.  St. 

14.49 

4.2 

1,697 

30.5 

12,330 

Battery 

6,722 

5,635 

1,087 

3.  Upper  East  river  (above 

Lawrence  Pt.)  

9.23 

7.0 

1,869 

21.4 

5,512 

Lawrence  Pt. 

*  (3,654) 

*(3,539) 

**(115) 

4.  Lower  East  river  

4.24 

4.7 

552 

35.4 

4,174 

Battery 

4,068 

3,968 

100 

5.  Harlem  river  (above  101st 

street)  

0.77 

5.5 

148 

13.3 

285 

High  Bridge 

176 

161 

15 

6.  Kill  van  Kull  

1.03 

4.8 

150 

25.3 

728 

Const.  Point 

1,479 

1,391 

88 

7.  Newark  bay  

8.06 

4.6 

1,071 

6.9 

1,542 

Mouth 

1,972 

1,867 

105 

8.  Arthur  Kill  

4.16 

5.4 

743 

15.0 

1,735 

Upper  End 

330 

297 

33 

9.  Jamaica  bay  

20.93 

4.3 

2,309 

3.9 

2,258 

Rockaway  Pt. 

1,989 

1,965 

24 

122.75 

4.9 

16,765 

Coneyls.-San- 

dy  Hook. 

24,658 

23,323 

1,335 

•Is  equal  to  East  river  discharge  past  Battery,  less  the  tidal  prism  of  the  Lower  East  river,  plus  the  flow  of  the 
Harlem  river  past  Willis  avenue. 

"Differs  from  ebb  excess  of  Lower  East  river  by  amount  of  ebb  excess  in  Harlem  river. 


CORRESPONDENCE— TIDAL  FLOW 


549 


CORRESPONDENCE  WITH  THE  UNITED  STATES  COAST  AND  GEODETIC 
SURVEY  IN  REGARD  TO  THE  TIDAL  PHENOMENA 

In  the  five  years  previous  to  May,  1913,  a  considerable  amount  of  correspondence 
was  exchanged  between  the  Metropolitan  Sewerage  Commission  and  the  U.  S.  Coast 
and  Geodetic  Survey  with  regard  to  questions  upon  which  the  Survey  was  properly 
regarded  as  an  authority.  These  questions  related  to  the  flow  of  water  in  and  out  of 
the  principal  parts  of  New  York  harbor,  especially  to  the  estimates  of  quantity  of 
water  passing  seaward  in  excess  of  the  flow  in  the  opposite  direction,  this  subject  be- 
ing of  much  importance  as  indicating  the  extent  to  which  the  sewage  of  New  York 
could  be  carried  mechanically  to  sea.  It  is  believed  that  the  most  important  part  of 
this  correspondence  should  be  published  in  full. 

There  is  the  more  reason  for  publishing  this  correspondence  in  the  fact  that 
some  of  the  leading  problems  raised  had  previously  received  a  different  solution  by 
the  Survey.  This  is  notably  true  of  the  resultant  flow  of  water  in  the  Lower  East 
river.  Until  the  opinions  here  published  were  expressed,  it  was  believed  that  there  was 
a  considerable  preponderance  of  water  flowing  southward  through  the  East  river  in 
excess  of  that  which  passed  northward  under  the  tidal  influences.  The  Survey  state- 
ments here  given  must  be  accepted  as  superseding  the  earlier  estimates.  The  latest 
opinion  is  that  there  is  little  or  no  excess  flow  in  either  direction. 

The  correspondence  is  divisible  into  three  principal  parts. 

Part  I  relates  to  the  tidal  flow  in  the  various  parts  of  the  harbor  and  especially 
to  the  excess  or  resultant  discharge  in  one  direction  over  the  reverse  flow. 

Part  II  relates  to  new  estimates  by  the  Commission  of  the  flow  of  the  East  river, 
based  on  data  collected  under  the  direction  of  Colonel  William  M.  Black,  Corps  of 
Engineers,  U.  S.  A. 

Part  III  is  concerned  with  the  probable  stability  of  an  artificial  island  which  the 
Commission  has  proposed  for  the  disposal  of  a  large  amount  of  sewage  at  the  ocean 
entrance  of  the  harbor. 


550 


DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


SECTION  I 

CORRESPONDENCE  RELATING  TO  THE  TIDAL  FLOW 

At  the  outset  of  its  work  in  1908,  the  Commission  recofrnized  the  need  of  a  com- 
prehensive knowledge  of  the  quantities  of  water  flowing  in  each  direction  through 
the  principal  divisions  of  the  harbor  and  contemplated  the  collection  of  the  necessary 
data  by  means  of  a  hydrographic  survey.  Before  undertaking  this  work,  it  was 
thought  desirable  to  ascertain  from  the  Survey  what  instruments  and  methods  were, 
in  the  Survey's  opinion,  most  serviceable  for  this  undertaking.  With  this  object  in 
view,  the  following  letter,  marked  Exhibit  I,  was  sent  under  date  of  May  8,  1908. 

EXHIBIT  I 

New  York,  May  8,  1908. 

Director, 

U.  S.  Coast  &  Geodetic  Survey, 
Washington,  D.  C. 

Dear  Sir  :  Will  you  kindly  send  me  such  information  either  in  the  form  of  de- 
scriptions or  references  as  may  be  available  concerning  methods  and  apparatus  for 
gauging  very  large  streams  such  as  tidal  currents  of  harbors  and  the  flow  of  great 
rivers  like  the  Hudson  in  the  vicinity  of  New  York  City? 

Very  sincerely, 

George  A.  Soper, 

President. 

On  May  27,  1908,  a  reply  was  received  describing  meters  and  other  apparatus 
which  had  been  used  in  various  studies  made  in  previous  years  of  the  tidal  phenomena 
of  New  York  harbor.  The  letter  also  contained  an  epitome  of  results  for  the  dis- 
charge of  four  of  the  principal  sections  of  New  York  harbor.  The  quantities  of 
water  given  in  this  epitome  represent  the  information  which  has  been  used  by  the 
Survey  for  the  last  22  years. 

It  is  noteworthy  that  the  volumes  of  water  reported  as  being  discharged  through 
the  different  parts  of  New  York  harbor  were  based  on  a  series  of  precise  levels  which 
were  run  for  the  connection  of  tide  gauges. 

Subsequent  to  the  studies  which  had  led  to  the  results  given  in  the  epitome,  cur- 
rent observations  were  made  covering  40  different  stations  over  a  period  of  two 
months. 


CORRESPONDENCE— TIDAL  FLOW 


551 


This  letter  from  the  Coast  Survey  indicated  that  a  considerable  amount  of  study 
had  been  given  to  the  tidal  phenomena  of  New  York  harbor  and  suggested  to  the 
Commission  that  it  would  be  desirable  before  taking  up  new  work  to  obtain  a  digest 
from  the  Survey  of  all  existing  facts  relating  to  the  specific  problems  which  the  Com- 
mission desired  information  upon.  The  letter,  describing  apparatus,  containing  the 
epitome  and  the  other  information  here  referred  to,  follows  as  Exhibit  II. 

EXHIBIT  II 

Washington,  D.  C,  May  27,  1908. 

Ms.  George  A.  Soper, 

President,  Metropolitan  Sewerage  Commission  of  New  York. 

Dear  Sir  :  In  reply  to  your  letter  of  May  8,  1908,  requesting  information  con- 
cerning methods  and  apparatus  for  gauging  very  large  streams,  such  as  tidal  currents 
of  harbors  and  the  flow  of  great  rivers  like  the  Hudson  in  the  vicinity  of  New  York 
City,  I  will  state  that  in  the  New  York  harbor  gauging  operations  made  by  the  Coast 
and  Geodetic  Survey  in  the  eighties,  electric  current  meters  were  principally  used  to 
determine  the  velocities.  The  meters  were  manipulated  from  ships  and  launches  an- 
chored at  the  place  where  the  velocities  were  to  be  taken. 

The  meters  were  lowered  to  the  desired  depth  by  means  of  a  wire  rope,  inside  of 
which  was  an  insulatd  core  containing  two  copper  wires  by  which  the  revolutions  of 
the  wheel  of  the  meter  were  registered  on  a  recording  apparatus  on  deck. 

As  the  weight  attached  to  the  meter  has  to  be  heavy  (60  to  100  lbs.)  in  strong 
sub-surface  currents,  the  lowering  rope  was  manipulated  by  a  reel  placed  on  deck. 
This  reel  was  so  devised  that  the  unwinding  and  winding  up  of  the  rope  on  the  drum 
of  the  reel  did  not  interfere  with  the  electric  current  passing  from  the  meter  to  the 
recording  apparatus. 

The  drum  was  also  made  of  such  diameter  that  the  number  of  revolutions  of  the 
drum  indicated  the  distance  the  meter  was  below  the  surface  of  the  water. 

Both  the  Price  and  Haskell  current  meters  were  used  in  the  New  York  Harbor 
work. 

The  Price  Current  Meter  is  manufactured  by  the  Gurley's  of  Troy,  N.  Y.  Their 
last  manual,  40th  edition,  gives  considerable  information  in  regard  to  this  meter  and 
other  matter  pertaining  to  the  manipulation  of  a  current  meter. 

The  Haskell  Meter  was,  and  I  think  still  is,  manufactured  by  Ritchie  Bros.,  of 
Brookline,  Mass.  They  also  manufacture  the  Ritchie-Haskell  Current-direction  Meter. 
This  latter  instrument,  in  addition  to  registering  the  current,  also  gives  the  direction 
of  the  current  at  the  same  time.  This  latter  information  is  very  desirable  at  times  and 
most  important  in  gauging  the  Hudson  river  in  the  vicinity  of  New  York  City. 

Our  observations  showed  that  at  certain  times  and  stages  of  the  tide,  the  under- 
run  of  the  flood  is  very  evident.  This  phenomenon  was  observed  at  the  Narrows — 
opposite  39th  street  on  the  Hudson — and  I  think  up  as  far  as  Dobbs  Ferry.  ( See  Ap- 
pendix No.  15,  C.  &  G.  S.  Report,  1887.)  For  the  gauging  of  New  York  Harbor  in  1885, 
current  observations  were  made  at  seven  discharge  sections,  viz. :  one  in  Arthur  Kill 
near  Elizabethport,  one  in  Kill  van  Kull  near  West  New  Brighton,  one  in  the  Narrows, 


552 


DATA  RELATING  TO  THE  PROTECTION  OP  THE  HARBOR 


one  in  East  river  at  19th  Street,  and  one  at  Old  Ferry  Point,  one  at  39th  Street,  Hud- 
son river,  and  one  at  Dobbs  Ferry,  Hudson  river. 

Tide  gauges  were  maintained  at  each  of  the  above  sections  during  the  period  of 
the  current  observations  at  least,  and  at  Governor's  Island  and  Sandy  Hook,  at  Elm 
Park  and  Elbow  Beacon  on  Newark  Bay,  Hell  Gate  Ferry,  Pot  Cove  and  Willet's 
Point  on  East  river,  and  Ossining  and  Iona  Island  on  the  Hudson.  In  addition,  cur- 
rent observations  were  also  made  on  the  outer  slope  of  New  York  Bar. 

Six  of  the  vessels  of  the  Survey,  together  with  steam  launches  and  boats,  their 
officers,  crews  and  additional  current  and  tidal  observers,  were  employed  during  the 
season's  work. 

The  principal  results  of  the  survey  are  given  in  Asst.  Henry  Mitchell's  Report, 
dated  March  24,  1888  (Appendix  No.  15,  C.  &  G.  S.  Report,  1887).  The  under-run  of 
the  Hudson  river,  densities  at  different  depths,  the  currents  at  different  times  and 
depths,  and  the  slopes  and  changes  of  slope  of  the  Hudson  and  East  rivers  are  given 
and  discussed.  An  unpublished  report  by  Asst.  E.  E.  Haskell  (June  30,  1886),  to 
Professor  Mitchell,  gives  the  reduction  of  the  gaugings,  giving  the  following  flood 
and  ebb  discharges  for  the  various  sections : 

TABLE  CV 
Epitome  of  Results  for  Discharge 

From  observations  made  between  July  28  and  Sept.  16,  1886 

East  river  (19th  street)  Ebb  (Westerly)   4,454,937,257  cubic  feet 

Flood  (Easterly   4,007,175,676  " 

Hudson  river  (39th  Btreet)  Ebb  (Southerly)   6,996,678,413  " 

Flood  (Northerly)   6,225,985,545  " 

Kill  van  Kull  (W.  New  Brighton)  Ebb  (toward  the  Harbor)   1,790,103.372  " 

Flood   1,712,415,362  "  « 

Narrows  Ebb  (Seaward)   13,819,895.144  " 

Flood   12,703,616,481  " 

In  the  observations  of  1886,  having  mainly  in  view  the  circulation  of  the  waters 
of  the  East  river  through  New  York  Harbor,  four  current  sections  were  occupied 
and  twenty-five  tide  stations  observed.  A  series  of  precise  levels  was  run  for  the 
connection  of  the  tide  gauges  used  in  the  physical  hydrography  investigation  of  New 
York  Harbor  and  vicinity.  Professor  Mitchell's  report  (App.  12,  Report  of  1886)  of 
May  6,  1887,  "On  the  circulation  of  the  sea  through  New  York  Harbor,"  gives  the 
results  of  this  investigation. 

Current  observations  were  made  at  the  entrance  to  New  York  Harbor  during  the 
summer  of  1887,  covering  a  period  extending  from  June  20th  to  August  10th.  Forty 
different  stations  were  occupied  during  that  time  and  they  were  taken  in  successive 
groups  or  sets  of  3  to  4  simultaneously  observed  stations;  they  were  taken  in  Four- 
teen Ft.,  East,  Swash,  Main  Ship,  Gedney  and  South  Channels.  Two  vessels,  two 
steam  launches  of  the  Survey  and  the  necessary  complement  of  boats  and  crew  were 
used  in  the  work.  Self-registering  tide  gauges  were  running  at  Bath  Beach  and  Sandy 
Hook  during  the  observations.  At  23  of  the  stations  occupied  for  velocity  observa- 
tions, specimens  showing  the  nature  and  composition  of  the  bottom  were  obtained, 
and  it  may  be  of  interest  to  note  that  the  field  record  of  the  dredged  specimens  in  the 
East  and  Swash  Channels  describes  some  of  the  specimens  as  "black,  sticky  ooze  or 
mud,  having  the  smell  and  appearance  of  refuse  from  oil  refineries  or  gas  works"  and 
"yellow  scum,"  "yellowish  scum,"  etc. 


CORRESPONDENCE— TIDAL  FLOW 


553 


A  report  giving  the  scope  of  the  work,  tabulation  of  all  the  observed  velocities, 
directions,  densities,  soundings,  dredgings  and  descriptions  of  instruments  and  ap- 
pliances used  is  in  the  archives  of  the  Survey. 

Appendix  No.  9,  Report  of  1888,  by  Assistant  Marindin,  "Tidal  Levels  and  Flow  of 
Currents  in  New  York  Bay  and  Harbor,"  demonstrates  the  movements  of  the  tide  in 
filling  and  draining  the  tidal  reservoirs  surrounding  New  York  City. 

In  addition  to  the  already  mentioned  Appendices  (No.  9,  1888,  and  No.  12,  1886, 
and  No.  15,  1887),  additional  data  bearing  on  the  subject  will  be  found  in  the  Survey's 
Reports  for  1856,  1858,  1859,  1866,  1867,  1871  and  1876,  and  Bulletin  No.  8. 

The  subject  of  current  and  discharge  measurements  has  been  extensively  gone 
into  by  the  Mississippi  River  Commission  and  a  great  number  of  observations  have 
been  and  are  still  being  made  by  them. 

By  their  present  method  of  taking  a  discharge  of  the  Mississippi  it  takes  but  a 
few  hours  to  complete  the  observations.  The  appliances  used  comprise  a  small  steamer 
and  one  meter  outfit.  One  of  the  time  consuming  items  they  do  away  with  is  that  they 
do  not  anchor,  but  make  the  observations  while  the  engineer,  with  hand  on  the  throttle, 
keeps  the  boat  on  the  cross-section  by  observing  a  fixed  range  on  shore,  care  being  taken 
that  the  beginning  and  ending  of  the  observation  is  made  when  the  boat  is  exactly  on 
range.  Likewise  the  boat  is  held  laterally  on  the  section  by  the  helmsman  observing 
a  diagonal  range  on  shore.  On  completion  of  the  observations,  the  boat  is  then  rapidly 
moved  to  the  next  station  on  the  cross-section,  and  so  on. 

Of  course  on  the  Mississippi  the  current  is  always  down  stream,  and  the  change  in 
the  velocities  are  slow  during  the  interval  of  observation,  and  a  succession  of  daily 
observations  permits  one  to  eliminate  even  that  small  source  of  error. 

By  consulting  the  reports  of  the  Commission,  especially  those  between  the  years 
1881  and  about  1886,  a  considerable  amount  of  detail  information  in  regard  to  ap- 
pliances and  methods  may  be  obtained.  Also  a  letter  to  the  Secretary  of  the  Commis- 
sion (1307  Liggett  Bldg.,  St.  Louis,  Mo.),  who  has  charge  of  the  present  observations, 
may  bring  some  up-to-date  information. 

Extensive  current  work  was  done  on  the  Niagara  River  a  few  years  ago.  Either 
the  U.  S.  Engineer  Reports  or  the  Reports  of  the  International  Waterway  Commission 
give  some  of  the  details  of  operation.  In  recent  years  the  Weather  Bureau  and  the 
Reclamation  Service  have  also  taken  up  the  subject  of  Current  Observation. 

Very  respectfully, 

O.  H.  TlTTMANN, 

Superintendent. 

Upon  the  receipt  of  the  letter  given  here  as  Exhibit  II,  the  Commission  requested 
the  Survey  to  give  careful  consideration  to  a  list  of  ten  specific  questions  concerning 
the  volume  of  water  discharging  through  the  different  parts  of  the  harbor  under  con- 
ditions which  were  both  usual  and  unfavorable  to  a  large  net  outflow  toward  the  sea. 
The  letter  described  the  uses  to  which  this  information  was  to  be  put  and  gave  the 
Survey  an  opportunity  to  understand  the  scope  and  extent  to  which  the  detail  was 
desired.   This  letter,  which  is  dated  June  19,  1908,  is  given  here  as  Exhibit  III. 


554 


DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


EXHIBIT  III 

New  York,  June  19,  1908. 

Mr.  O.  H.  Tittmann,  Superintendent, 
Coast  and  Geodetic  Survey, 
Washington,  D.  C. 

My  Dear  Prof.  Tittmann  :  After  giving  due  consideration  to  the  various  subjects 
discussed  at  the  interviews  which  Mr.  Sooysmith  and  I  had  the  pleasure  of  holding  with 
Secretary  Straus,  and  later  with  you  and  Mr.  Perkins,  and  in  view  of  the  necessities 
of  the  work  upon  which  the  Metropolitan  Sewerage  Comniission  is  engaged,  it  has 
seemed  desirable  to  form  the  following  list  of  specific  questions  as  a  basis  for  infor- 
mation which  your  Survey  is  requested  to  supply.  In  order  that  you  shall  have  the 
benefit,  so  far  as  possible,  of  our  point  of  view  in  requesting  this  information,  there 
are  sent  to  you,  under  another  cover,  a  reprint  of  a  paper  by  one  of  us  on  the  pollu- 
tion of  New  York  harbor  and  the  final  report  of  the  New  York  Bay  Pollution  Com- 
mission. The  first  report  of  the  New  York  Bay  Pollution  Commission,  containing 
specific  references  to  data  published  by  your  office  on  tidal  phenomena  of  New  York 
harbor,  is  sent  you  at  the  same  time.  This  is  the  last  copy  of  this  report  which  is 
available,  the  edition  having  been  exhausted  several  years  ago. 

The  flow  of  water  through  New  York  harbor  is  interesting  to  the  Metropolitan 
Sewerage  Commission  for  a  number  of  reasons,  chief  of  which  are  the  following: 

The  sewage,  that  is  the  refuse  which  is  carried  by  underground  pipes  and  chan- 
nels from  dwellings,  manufactories  and  from  the  surface  of  the  earth  during  rain 
storms,  is  now  discharged  into  the  harbor  and  its  tributaries  without  restriction  as 
to  locality,  quantity  of  waste,  movement  or  volume  of  tide  water  at  the  point  of  dis- 
charge or  other  restriction.  Laws  exist  and  are  enforced  to  restrict  the  dumping  of 
solid  refuse  such  as  ashes  and  kitchen  waste  into  the  harbor,  but  manufacturers  and 
municipal  corporations  are  permitted  to  dispose  of  their  drainage  as  they  see  fit. 
The  pursuit  of  this  custom  through  many  years  has  resulted  in  producing  many  ex- 
tensive nuisances,  of  which  the  Passaic  river  in  New  Jersey  and  Newtown  and 
Gowanus  creeks  in  New  York  are  among  the  worst  examples.  The  waters  of  these 
streams  are  highly  polluted  and  the  odors  from  them  are  exceedingly  offensive.  Plans 
have  been  made  to  sanitate  the  most  polluted  waters  in  the  metropolitan  district  by 
carrying  this  sewage  and  other  drainage  to  the  main  channels  of  the  harbor.  Exten- 
sive projects  have  been  executed,  others  are  being  begun  and  some  are  in  contempla- 
tion for  carrying  large  quantities  of  sewage  from  areas  not  immediately  bordering 
upon  the  harbor  to  the  main  body  of  the  Upper  harbor  for  disposal.  One  of  these 
projects  is  that  of  the  Passaic  Valley  Sewerage  Commission,  concerning  which  you 
will  find  information  in  the  printed  matter  already  referred  to  in  this  letter. 
Another  is  the  project  of  the  Bronx  Valley  Sewer  Commission  which  will  discharge 
unpurified  sewage  into  the  Hudson  immediately  above  the  boundary  line  of  New  York 
City.  The  third  is  the  project  for  improving  Gowanus  Canal;  in  this  case  water 
from  the  Upper  bay  will  be  pumped  through  a  channel  to  the  head  of  the  canal  in 
order  to  flush  out  the  polluted  water  into  the  harbor. 

Persons  who  advocate  sanitating  small  arms  of  the  harbor  at  the  expense  of  the 
water  in  the  main  channels,  argue  that  there  is  an  abundance  of  water  from  the  rivers 
and  ocean  to  dilute,  diffuse  and  dispose  of  the  impurities  of  all  the  municipalities  in 


CORRESPONDENCE— TIDAL  FLOW 


555 


the  metropolitan  district  for  practically  all  time  to  come.  In  this  calculation  the 
quantity  of  water  which  enters  and  leaves  the  harbor  at  each  tide  serves  as  a  basis 
upon  which  to  compare  the  quantity  of  sewage  which  needs  to  be  diluted  and  dis- 
posed of.  It  is  generally  believed  by  the  public  that  the  harbor  is  flushed  out  very 
much  as  a  watercloset  is  flushed,  by  the  action  of  the  tide. 

On  the  other  hand,  there  are  those  who  say  that  the  harbor  is  polluted  inadmis- 
sibly,  that  banks  of  mud  have  been  formed  from  the  solid  matters  carried  by  the  sew- 
age, that  the  sanitating  of  the  tributaries  of  the  harbor  at  the  expense  of  the  waters 
in  the  main  channels  will  lead  to  nuisance,  that  practically  nothing  is  known  con- 
cerning the  fate  of  the  sewage  when  it  is  discharged  into  the  tidal  currents  except 
that  it  produces  an  offense  to  the  eye  in  the  neighborhood,  and  that  untoward  conse- 
quences must  follow  if  large  additions  of  sewage  are  to  be  made  to  the  polluting  con- 
ditions which  exist  already.  Those  persons  who  are  most  insistent  for  a  clean  harbor 
advance  the  idea  that  the  tidal  waters  oscillate  back  and  forth  in  New  York  harbor 
and  that  there  is  not  a  flushing  action  that  can  be  depended  upon  to  carry  sewage  to 
sea  in  anything  like  a  regular  and  reliable  way.  This  is  the  main  manner.  It  is  the 
duty  of  the  Metropolitan  Sewerage  Commission  (See  Chapter  639,  Laws  of  1906,  and 
Chapter  422,  Laws  of  1908,  New  York  State)  to  make  a  thorough  investigation  of 
the  conditions  of  sewage  disposal  in  the  metropolitan  district  of  New  York  and  New 
Jersey  and  formulate  a  general  plan  or  policy  for  keeping  these  waters  reasonably 
pure.  Some  work  has  been  done  along  this  line  and  more  will  be  undertaken  by  em- 
ployees working  under  the  immediate  direction  of  this  Commission.  The  Coast  and 
Geodetic  Survey  is  requested  as  a  federal  authority  charged  with  the  duty  of  inves- 
tigating questions  of  tidal  phenomena  and  possessing  special  experience  in  studying 
tidal  conditions  in  New  York  harbor  to  supply  information  within  its  scope  for  the 
use  of  the  Metropolitan  Commission  in  its  investigation.  It  is  not  expected  that  the 
Survey  will  enter  deeply  into  biological,  chemical  or  sanitary  questions  involved,  al- 
though information  and  suggestions  with  regard  to  these  topics  would  be  welcome. 
What  the  Metropolitan  Sewerage  Commission  desires  especially  is  information  con- 
cerning the  physical  phenomena  of  tidal  currents,  their  volume,  direction,  velocity 
and  regularity. 

It  is  understood  by  the  Metropolitan  Sewerage  Commission  that  the  Coast  and 
Geodetic  Survey  has  already  at  hand  a  large  amount  of  information  concerning  the 
currents  of  New  York  harbor,  some  of  which  data  remain  in  the  archives  of  the  Survey 
and  some  published.  The  Metropolitan  Sewerage  Commission,  representing  the  City 
and  State  of  New  York,  request  that  a  study  of  all  existing  information  in  the  posses- 
sion of  and  accessible  to  the  Survey  be  examined  and  digested  for  the  Metropolitan 
Sewerage  Commission,  having  in  mind  the  work  before  this  Commission.  On  the 
receipt  of  a  communication  from  the  Survey  giving  the  results  of  the  Survey's  study, 
if  recommendation  is  made  for  studies  in  the  field  in  order  to  supplement,  verify  or 
extend  the  information,  the  Metropolitan  Commission  will  be  pleased  to  consider  any 
plan  and  estimate  for  that  work  which  the  Survey  may  propose.  If  in  the  study  of 
existing  data  two  or  three  expert  assistants  are  needed  to  expedite  the  work,  the  Met- 
ropolitan Commission  will  be  pleased  to  authorize  the  Survey  to  do  so  at  the  expense 
of  this  Commission.  It  is  desirable  that  immediate  attention  be  given  to  this  matter 
since  the  results  are  likely  materially  to  modify  several  lines  of  investigation  which 
the  Metropolitan  Commission  will  undertake.  The  time  remaining  to  the  life  of  this 
Commission  is  brief. 


556         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


The  subjects  upon  which  the  Metropolitan  Sewerage  Commission  request  infor- 
mation from  the  Coast  and  Geodetic  Survey  may  be  included  in  the  following  list 

of  questions : 

1.  What  is  the  volume  of  water  discharged  through  the  Narrows  in  each  direc- 
tion at  each  tide  under  conditions  which  are  (a)  usual  and  (b)  unfavorable  to  a  large 
net  outflow  toward  the  sea? 

2.  What  are  the  principal  current  phenomena,  at  the  Narrows  and  at  other 
points  in  the  harbor,  which  accompany  this  discharge? 

3.  What  is  the  volume  of  water  discharged  in  each  direction  at  each  tide  at  con- 
trolling points  in  the  harbor,  notably  the  mouth  of  the  Hudson  river,  the  East  river, 
the  Harlem  river,  Kill  van  Kull,  the  Arthur  Kill  under  conditions  which  are  (a) 
usual,  and  (b)  unfavorable  to  a  large  flow  toward  the  sea? 

4.  What  are  the  main  tidal  phenomena  of  the  Passaic  river,  Gowanus  Canal, 
Newton  creek,  Bronx  river,  Rah  way  river,  Jamaica  bay,  Shrewsbury  river  and  Rar- 
itan  river? 

5.  Is  there  a  discharge  of  water  through  the  East  river  and  New  York  bay  from 
Long  Island  sound  to  the  sea,  and  if  so,  how  great  is  it  under  (a)  usual  conditions  and 
(b)  conditions  which  are  unfavorable  to  the  discharge  of  water  from  the  harbor? 

6.  To  what  extent  have  changes  in  the  depth,  width  and  location  of  the  chan- 
nels and  the  construction  of  islands  and  bulkheads  affected  the  flow  of  water  through 
the  harbor? 

7.  In  general  terms,  what  are  the  controlling  factors  which  affect  the  flow  of 
water  in  and  out  of  New  York  harbor?  Especially  what  is  the  effect  produced  by 
the  wind? 

8.  Would  it  be  feasible  to  establish  a  system  of  gauges  in  and  about  New  York 
which  would  permit  the  city  to  make  a  calculation  at  any  time  of  the  quantities  of  water 
being  carried  in  the  main  tidal  currents? 

9.  What  are  the  average,  the  maximum  and  minimum  velocities  in  each  direction 
of  the  currents  at  the  principal  points  in  New  York  harbor  taken  at  the  time  when 
each  current  is  strongest?  That  is,  how  do  the  velocities  vary  with  different  tides 
through  the  year. 

10.  What  is  the  distance  that  water  moves  in  different  parts  of  the  harbor 
through  a  complete  tide,  from  high  water  to  high  water  and  from  low  water  to  low 
water  as  shown  by  floats,  and  what  is  the  net  movement  of  the  water  starting  from 
different  points  toward  the  sea? 

We  shall  be  pleased  to  answer  any  inquiries  you  may  make  in  order  to  make 
these  questions  explicit.  We  have  purposely  endeavored  to  give  you  considerable  lat- 
itude in  your  replies  and  have  prefaced  this  letter  with  a  statement  of  our  point  of 
view  in  order  that  you  may  use  your  judgment  and  collect  your  data  in  the  way 
which  appears  to  be  most  likely  to  give  us  the  information  we  desire. 

Hoping  you  will  be  able  to  give  us  your  full  reply  as  soon  as  possible,  we  are, 

Very  sincerely, 

George  A.  Sopek, 

President. 


CORRESPONDENCE— TIDAL  FLOW  557 

The  reply  of  the  Survey  to  the  letter  printed  here  as  Exhibit  III  was  dated 
August  14,  1908,  and  appears  here  as  Exhibit  IV. 

EXHIBIT  IV 

Washington,  D.  C,  August  14,  1908. 

Mr.  George  A.  Soper, 

President,  Metropolitan  Sewerage  Commission, 
17  Battery  Place,  New  York  City. 

Sir:  In  reply  to  the  questions  contained  in  your  letter  dated  June  19,  1908,  I 
have  the  honor  to  submit  the  following  statements : 

Before  taking  up  the  questions  in  their  regular  order,  it  seems  best  to  give  the 
fresh-water  discharge  or  run-off  for  the  regions  considered. 

Gauging  stations  have  been  maintained  by  the  U.  S.  Geological  Survey,  in  con- 
junction with  the  State  Engineer  and  Surveyor,  at  Mecbanicsville  on  the  Hudson 
and  at  a  point  on  the  Mohawk  river  about  4  miles  below  Rexford  Flats.  The  areas 
above  these  stations,  and  whose  drainage  passes  by  them,  are  shown  in  the  below 
table.  Now  the  amount  of  fresh  water  running  off  from  areas  below  these  gauging 
stations  might  be  assumed  to  be  related  to  these  areas  as  the  measured  discharges  are 
to  the  areas  above  the  gauging  station.  Such  values  are  given  in  the  below  table.  But 
a  closer  approximation  to  the  truth  would  be  the  values  just  referred  to,  multiplied 
by  factors  representing  the  ratios  of  the  annual  rainfall  over  the  regions  under  con- 
sideration to  the  annual  rainfall  over  the  regions  above  the  two  gauging  stations. 
These  ratios  have  been  obtained  from  Plate  26,  Climatology  of  the  United  States, 
Prof.  A.  J.  Henry,  and  the  results  after  having  applied  the  factor  are  also  shown  in 
the  table. 

The  final  or  adopted  results  are  the  underscored  values. 


558         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


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560         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


1.  What  is  the  volume  of  water  discharged  through  the  Narrows  in  each  direc- 
tion at  each  tide  under  conditions  which  are  (a)  usual  and  (b)  unfavorable  to  a 
large  net  outflow  toward  the  sea? 

At  Fort  Wadsworth  the  width  of  the  Narrows  is  1  statute  mile,  or  5,280  feet,  and 
the  average  depth  at  half-tide  level  61  feet,  thus  making  the  area  of  the  section 
322,080  square  feet.  Judging  from  observations  made  near  this  section  in  1858,  1885, 
and  1886,  it  appears  that  the  value  of  the  strength  of  the  flood  or  ebb  stream  meas- 
ured when  the  surface  current  is  greatest  is  2.0  knots  per  hour,  or  3.378  feet  per 
second.  Now,  according  to  rules  which  have  been  deduced  in  connection  with  vari- 
ous rivers,  the  mean  or  cross-sectional  velocity  is  about  0.75  times  the  value  of  the 
velocity  belonging  to  the  swiftest  surface  thread.   Cf. : 

Encyclopaedia  Britannica,  Vol.  12,  pp.  509,  510. 

Darcy  and  Bazin:  Recherches  Hydrauliques  (Atlas),  Plates  19-23. 

Merriman:  A  Treatise  on  Hydraulics  (4th  Ed.),  Art.  113. 

Bovey:  A  Treatise  on  Hydraulics  (2d  Ed.),  p.  259. 

Murphy:  Accuracy  of  Stream  Measurements  (Water- Supply  and  Irrigation 
Paper  No.  95),  p.  138. 

The  maximum  surface  velocity  being  2.0  knots,  the  cross-sectional  velocity  will, 
according  to  the  above  rule,  be  2.0X0.75  or  1.5  knots  per  hour =2. 5335  feet  per 
second. 

The  entire  volume  of  tide  water  passing  this  section  during  a  flood  or  ebb  period 
of  6  lunar  hours,  or  22,357  seconds,  is,  since  the  current  curve  is  approximately  a 
sine  curve, 

-|  X  22,357  X  322,080  X  2 . 5335 
*==  14,233X322,080X2.5335= 

4,584,164,640  X  2 . 5335= 11,613,981,014 
cubic  feet.    The  above  velocities  are  for  ordinary  maximum  or  strengths  of  flood  or 
ebb.    They  vary  during  the  month  about  as  the  rise  or  fall  (range)  of  tide  upon 
which  they  occur  varies.    The  amount  of  this  variation  can  be  ascertained  from  the 
answer  to  question  No.  7. 

Mitchell's  estimate  based  upon  observations  made  in  1885  and  given  upon  page 
36,  Coast  and  Geodetic  Survey  Report  for  1886,  is  13,261,755,813  cubic  feet. 

2.  What  are  the  principal  current  phenomena,  at  the  Narrows  and  at  other 
points  in  the  harbor,  which  accompany  this  discharge? 

The  principal  tidal  current  phenomena  can  be  seen  from  the  charts  constituting 
Figs.  No.  12  and  13,  Appendix  No.  6,  Coast  and  Geodetic  Survey  Report  for  1907. 
The  Roman  numerals  denote  the  Greenwich  lunar  time  of  the  strength  of  flood.  The 
"tidal  hours"  given  at  the  bottom  of  each  page  show  the  Greenwich  lunar  times  of 
high  and  low  waters.  Consequently,  the  times  of  the  maximum  current  can  be  com- 
pared directly  with  the  times  of  the  tide.  For  instance,  it  will  be  noticed  (from  Fig. 
13)  that  the  time  of  maximum  flood  current  at  the  mouth  of  the  Hudson  river  occurs 
at  very  nearly  the  time  of  high  water  at  Governor's  Island,  whose  high-water  tidal 
hour  is  given  as  XII. 73.  It  will  also  be  noticed  that  the  flood  (or  ebb)  current  in 
Kill  van  Kull  is  2y2  lunar  hours  earlier  than  the  flood  (or  ebb)  in  the  axis  of  the 
upper  bay. 

1  lunar  hour=l.  03505  solar  hours. 

The  sharp  arrows  with  numerals  written  upon  them  denote  the  direction  and 
velocities  of  the  flood  stream,  at  the  time  of  its  strength  or  maximum  velocity. 


CORRESPONDENCE— TIDAL  FLOW 


561 


The  blunt  arrows  denote  the  non-tidal  surface  stream  which  happened  to  be  run- 
ning at  the  time  when  the  observations  were  taken.  On  account  of  the  shortness  of 
the  periods  of  observation,  no  great  weight  should  be  attached  to  the  velocities  de- 
noted by  the  blunt  arrows.  The  permanent  or  net  discharge  should  be  taken  from  the 
table  given  above. 

In  the  Hudson  river  the  tidal  currents  are  due  chiefly  to  the  progressive  wave 
motion  there  existing.  This  is  proved  by  the  fact  that  the  greatest  flood  and  ebb 
velocities  occur  at  very  nearly  the  times  of  the  local  high  and  low  waters.  Through 
Kill  van  Kull  and  Arthur  Kill  the  tidal  currents  are  nearly  hydraulic ;  i.  e.,  they  flow 
from  the  body  having  temporarily  the  higher  surface  level  to  the  one  having  tempo- 
rarily the  lower.  The  flow  is  caused  by  a  difference  in  head  which  temporarily  exists 
between  the  bodies  connected.  The  same  is  true  of  the  currents  through  East  river, 
and  is  probably  true  for  those  through  the  Harlem. 

The  distance  over  which  any  floating  particle  will  be  carried  by  the  tide  can  be 
estimated  from  Figs.  12  and  13,  referred  to  above.  These  charts  show  the  currents 
at  the  time  of  strength.  At  any  other  time  they  may  be  inferred  from  those  given. 
Suppose  at  a  given  place  the  strength  of  the  tidal  current  is  A.  At  any  other  time 
the  velocity  will  be  A  cos  30  t  where  t  denotes  the  number  of  lunar  hours  after  the 
time  of  strength.  If  solar  hours  are  used  then  the  velocity  will  be  A  cos  *29.98  t.  By 
computing  and  plotting  a  number  of  these  velocities  at  each  of  several  stations  in  the 
locality  concerned  it  is  possible  to  make  an  estimate  of  how  a  floating  particle  will 
be  drifted  by  the  currents. 

In  a  channel  where  the  current  does  not  vary  much  from  point  to  point  in  the 
direction  of  the  motion,  a  particle  having  a  velocity  of  A  knots  per  (solar)  hour  will 
not  be  driven  from  its  mean  position  by  a  distance  A  X  length  of  ^  tidal  period  or 
AX 3.10515  but,  because  of  the  harmonic  or  sine  like  character  of  the  motion,  the  dis- 
tance from  the  mean  position  will  be 

2.AX3.10515  knots 

7T 

or  about  two-thirds  of  the  distance  which  would  be  covered  were  the  maximum  or 
strength  velocity  maintained  throughout  the  quarter  tidal  period. 

(Corrections.  On  the  chart  (Fig.  13)  the  station  between  Governors  Island  and 
Bedloe  Island  should  be  moved  a  short  distance  westward  so  as  to  conform  to  the 
position  given  on  p.  387,  Coast  and  Geodetic  Survey  Report  for  1907.  On  p.  385  same 
Report,  the  strength  of  the  ebb  stream  for  the  station  off  23d  street,  East  river,  should 
read  2.62  instead  of  1.72.  The  arrows  upon  Fig.  13  should  be  altered  in  accordance 
with  this  correction.) 

The  strong  currents  through  the  Narrows  and  the  fact  that  the  strength  of  flood 
or  ebb  occurs  considerably  earlier  than  the  time  of  high  or  low  water  indicates  that 
they  are  largely  hydraulic;  i.  e.,  due  to  a  difference  in  head  between  the  waters  of 
the  upper  bay  and  the  waters  outside.  There  is,  however,  considerable  progressive 
wave  motion  accompanying  this  hydraulic  motion. 

The  answers  to  most  of  the  other  questions  have  a  bearing  upon  the  answer  to 
this  one. 

3.  What  is  the  volume  of  water  discharged  in  each  direction  at  each  tide  at 
controlling  points  in  the  harbor,  notably  the  mouth  of  the  Hudson  river,  the  East 

•This  should  be  28.98— K.  A. 


562         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


river,  the  Harlem  river,  Kill  van  Kull,  the  Arthur  Kill,  under  conditions  which  are 
(a)  usual,  and  (b)  unfavorable  to  a  large  flow  toward  the  sea? 

Between  Battery  Place  and  Comniunipaw  Ferry  the  width  of  the  river  is  4,500 
feet  and  the  average  depth  at  half-tide  level  is  40  feet;  the  area  of  the  section  is 
therefore  180,000  square  feet.  Judging  from  current  observations  made  near  this 
section  in  1854,  1855,  1858,  1872,  1873,  it  appears  that  the  velocity  of  the  tidal  cur- 
rent at  the  time  of  their  strength,  or  ordinary  maximum,  is  1.9  knots  for  the  portion 
of  the  stream  having  the  greatest  surface  velocity.  According  to  the  rule  mentioned 
in  the  answer  to  No.  1,  the  average  velocity  of  the  cross  section  is  about  0.75  of  1.9 
knots=  1.425  knots  per  hour  =  2.4068  feet  per  second. 

The  entire  volume  of  tide  water  passing  this  section  during  a  flood  or  ebb  period 
of  6  lunar  hours,  or  22,357  ordinary  seconds,  is, 

14,233  X  180,000  X  2.4068 
=  6,166,077,192  cubic  feet. 

14,233 =J-X22,357. 

7T 

Mitchell's  estimate  based  upon  observations  made  in  1858  and  1872,  given  upon 
page  118,  U.  S.  Coast  Survey  Report  for  1871,  is  4,511,000,000  cubic  feet;  while  his 
latest  estimate,  given  upon  page  36,  Report  for  1886,  is,  for  a  section  off  39th  street, 
6,611,331,779. 

At  Green  street,  Greenpoint,  Brooklyn,  the  width  of  East  river  is  3,000  feet,  while 
the  half-tide  level  average  depth  is  32  feet.  The  area  of  the  section  is,  therefore, 
96,000  square  feet.  Current  observations  made  near  this  section  in  1854,  1858,  1873, 
1885  and  1886  indicate  a  maximum  surface  velocity  of  2.4  knots.  Upon  the  assump- 
tion used  in  connection  with  the  Narrows  and  the  Hudson  river  the  cross-sectional 
velocity  will  be  1.8  knots,  or  3.0402  feet  per  second.  This  velocity  gives  as  the  tidal 
volume  passing  this  cross-section 

14,233X96,000X3.0402=4,154,031,994  cubic  feet. 
The  value  of  this  tidal  volume,  as  given  upon  page  118  of  the  Coast  Survey  Report  for 
1871,  is  4,383,000,000  (ebb),  and  upon  page  36  of  the  Coast  and  Geodetic  Survey  Re- 
port for  1886  is  4,231,056,466  cubic  feet. 

Off  81st  street  the  width  of  the  west  channel  is  800  feet,  the  average  half-tide 
depth  is  39  feet  and  so  the  area  of  the  section  is  31,200  square  feet.  Similar  numbers 
for  the  east  channel,  a  little  southward  from  Graham  avenue,  are  600,  26V2  and 
15,900  respectively. 

In  the  former  section  the  maximum  surface  velocity  is  4.9  knots  and  in  the  latter 
4.0  knots,  according  to  observations  made  in  1857  and  1874.  The  cross-sectional 
velocity  for  the  west  channel  at  the  time  of  strength  will,  according  to  the  rule 
already  used,  be  3.675  knots  per  hour=  6.2069  feet  per  second.  For  the  east  channel 
it  will  be  3  knots  per  hour =5. 0670  feet  per  second. 

The  volume  passing  the  western  section  in  6  lunar  hours  is 

14,233X31,200X6.2069=2,756,295,600  cubic  feet,  and  that  passing  the  eastern 

14,233X15,900X5.067=1,146,685,915  cubic  feet. 

The  sum  of  these  two  volumes  is  3,902,981,515  cubic  feet. 

This  Survey  has  made  no  current  observations  in  the  Harlem  river  proper. 

A  section  near  the  mouth  of  Kill  van  Kull,  between  Constable  Point  and  New 
Brighton,  measures,  at  mean  water  stage,  1,425  feet  in  width  and  27  feet  in  depth,  the 
area  of  the  section  therefore  being  38,475  square  feet. 


CORRESPONDENCE— TIDAL  FLOW 


563 


Current  observations  made  in  1856  and  1885  indicate  a  maximum  surface  velocity 
for  this  section  of  2.3  knots  at  the  time  of  ordinary  strength.  Applying  the  same  rule 
at  that  used  for  the  Hudson  river  the  velocity  for  the  cross-section  at  the  time  of 
strength  would  be  1.725  knots  or  1.725X1-689=2.9135  feet  per  second.  This  velocity 
gives  as  the  tidal  volume  passing  this  cross  section 

14,233X38,475X2.9135=1,595,475,341  cubic  feet. 

The  theoretical  velocity  for  a  section  extending  across  Kill  van  Kull  is 
Area  Newark  bay  and  branches  at  H.  T.  L.      rate  Qf  rige  and  faR  of  gurface  of  ^  bay 
Area  cross  section  at  Half  Tide  level 

The  level  of  the  bay  and  nearby  branches  rises  and  falls  about  4.5  feet.  The  interval  of 
time  between  high  and  low  water  is  approximately  6  lunar  hours,  or  22,357  ordinary 
seconds.  Since  rise  and  fall  is  approximately  harmonic,  or  sine  like,  the  velocity  of 
the  current  at  the  time  of  strength  will  be  ~  (=1.5707963)  times  the  average 
velocity  y  -r-  22,357=0.00007025971. 

The  area  of  the  waters  above  this  section,  including  most  of  the  Kill  van  Kull, 
Newark  bay,  the  Passaic  river  as  far  as  the  Falls,  and  the  Hackensack  river  and 
branches,  measures  15.3  square  statute  miles,  or  426,539,520  square  feet.  The  cross- 
sectional  velocity  at  the  time  of  strength  would  be,  if  Arthur  Kill  were  cut  off  from 
Newark  bay  by  a  dam  at  Elizabethport, 
42fi  ^0 

"'' X  0.00007025971X4.5=3.505093  feet 

per  second.  The  tidal  volume  is  426,539,520X4.5=1,919,427,840  cubic  feet,  the  most  of 
which  passes  through  Kill  van  Kull. 

According  to  the  estimate  made  upon  page  36,  Coast  and  Geodetic  Survey  Report 
for  1886,  the  tidal  volume  passing  the  Kill  van  Kull  at  West  New  Brighton  is  1,751,- 
259,867  cubic  feet. 

A  few  observations  made  in  the  Arthur  Kill  off  Elizabethport,  just  above  the  mouth 
of  the  Elizabeth  river,  in  1856  and  1885,  indicate  a  maximum  surface  velocity  of  1.8 
knots  or  18/23  the  value  observed  in  Kill  van  Kull.  The  section  of  Arthur  Kill  is 
about  600X16=9,600  square  feet,  which  would  be  equivalent  to  18/23  of  9,600,  or 
*7854.5  square  feet  if  the  velocity  were  2.3  knots  instead  of  1.8  knots.  Hence  the  com- 
puted velocity  in  Kill  van  Kull  should  be  reduced  by  the  ratio 

38,475+7,513  =  08366313- 
3.505093  multiplied  by  this  number  gives  2.9324705  as  the  theoretical  cross-sectional 
velocity  of  Kill  van  Kull.   The  computed  tidal  volume  multiplied  by  the  same  number 
gives  1,605,853,409  for  the  corrected  theoretical  amount  entering  and  leaving  Kill  van 
Kull. 

This  agrees  well  with  the  results  from  determination  first  given. 

Of  the  waters  entering  and  leaving  Newark  bay  and  tributaries,  about  84  per 
cent,  passes  Kill  van  Kull  and  16  per  cent,  passes  the  upper  end  of  Arthur  Kill. 

Final  check.  Reckoned  in  billions  of  cubic  feet,  the  tidal  flow  during  a  complete 
flood  or  ebb  of  6  lunar  hours  is  as  follows : 

The  Narrows  (Fort  Wadsworth)   11.61 

The  Hudson  (Battery  place)   6.17 

East  river  (Green  street)   4.15 

  Kill  van  Kull  (Near  East  end)   1 . 60 

•Should  be  7513 — see  Letter  of  Perkins  to  Allen,  Sept.  30,  1908.  The  correct  value  has  been  used  in  computa- 
tion.   Change  made  here  by  G.  A.  S. 


564         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


From  Fig.  13,  referred  to  above,  the  current  hours  for  water  flowing  towards  the 
Upper  bay  are  as  follows: 


Hour  Equivalent  in  Degrees 

The  Narrows    XI. 6   348 

The  Hudson      VI .  8  ( =  XII .  8  —  6)   204 

East  river  V.3  (=   XI. 3  — 6)   159 

KiUvanKuU    III. 8  (=   IX. 8  — 6)   114 


Now  it  is  known  with  a  good  degree  of  accuracy  that  the  semi-daily  tidal  wave 
attains  its  maximum  height  in  the  upper  bay  XII. 84  o'clock,  and  so  the  time  of  half- 
tide  level  (rising)  will  be  XII.84— 3=IX.S4=295°.  Evidently  the  rate  influx  into 
the  harbor  should  be  greatest  at  the  time  of  half -tide  level  rising.  The  rate  influx  at 
any  time  t  is  proportional  to 

11.61  cos  (30  t— 348)+6.17  cos  (30  t— 204). 
+4.15  cos  (30  t— 159)  +1.60  cos  (30  t— 114). 

If  t  denote  the  time  of  maximum  influx  (=IX.84),  the  following  relation 
should  obtain : 

11.61  sin  (295°— 348) +6.17  sin  (295—204) 
+4.15  sin  (295  —159) +1.60  sin  (295— 114)  =0. 

The  sum  of  the  positive  terms  comes  out  9.05  and  of  the  negative  terms  —9.30,  or 
within  2  or  3  per  cent,  of  exact  agreement.    The  amount  of  the  influx  for  a  tide  is 

11.61  cos  (295— 348) +6.17  cos  (295—204) 
+4.15  cos  (295— 159) +1.60  cos  (295—114). 
This  comes  out  as  2.29.  Now  the  area  of  the  Upper  bay  between  the  sections  just 
mentioned  is  22  square  statute  miles=613,324,800  square  feet.  This  multiplied  by  the 
range  of  tide,  4.4  feet,  gives  2.6986  billions  of  cubic  feet  as  the  tidal  volume.  This 
does  not  agree  with  the  above  value,  2.29,  very  closely,  but  being  a  quantity  depend- 
ing upon  the  excess  of  the  water  flowing  through  the  Narrows  over  the  water  flowing 
out  through  the  three  other  openings,  its  value  is  very  sensitive  varying  greatly  for 
small  variations  of  the  assumed  data. 

The  foregoing  estimates  of  the  fresh  water  discharge,  and  the  volumes  of  tide  water 
passing  the  given  cross  sections,  have  been  made  by  methods  quite  different  from 
those  used  by  Professor  Mitchell,  and  there  is  a  general  agreement  between  the 
results  just  obtained  and  those  obtained  by  him.  In  the  present  instance,  care  has 
been  taken  to  reduce  observed  current  velocities  to  their  mean  or  ordinary  condition, 
i.e.,  to  correct  for  the  fact  that  the  ranges  of  tide  upon  the  days  when  current  observa- 
tions were  taken  generally  differed  from  their  mean  values.  Wherever  it  has  been 
found  necessary  to  resort  to  empirical  rules,  it  has  been  so  stated  and  these  have  been 
made  as  few  and  as  simple  as  seemed  possible. 

One  of  the  chief  uncertainties  connected  with  the  measurements  has  been  the 
widths  of  the  channels  where  piers  or  wharves  project  into  them.  These  certainly 
change  the  character  of  the  flow  along  the  shore  and  the  amount  will  depend  upon 
the  openness  of  their  substructures. 

If  the  present  estimates  are  deemed  inadequate  for  the  purpose  of  the  Commis- 
sion, it  would  seem  that  the  only  way  to  obtain  improved  values  would  be  to  gauge 
more  extensively  with  a  meter  each  of  the  given  cross-sections.  The  gauging  should 
be  made  at  regular  intervals  of  distance  from  one  end  of  the  cross-section  and  at  reg- 
ular height  intervals.  This  should  be  continued  day  and  night  for  two  or  four  weeks. 
Each  section  would  require  as  many  observing  parties  as  there  are,  say,  hundred-foot 
intervals  across  the  stream. 


CORRESPONDENCE— TIDAL  FLOW 


565 


4.  What  are  the  main  tidal  phenomena  of  the  Passaic  river,  Gowanus  Canal,  New- 
town creek,  Bronx  river,  Rahway  river,  Jamaica  bay,  Shrewsbury  river  and  Raritan 
river? 

The  Passaic  river,  Newtown  creek,  Bronx  river,  Rahway  river  and  Raritan  river, 
are  imperfect  examples  of  tidal  rivers  with  estuaries.  In  such  streams  there  is  a 
tendency  for  the  maximum  flood  velocity  to  occur  less  than  three  hours  before  the 
time  of  local  high  water  and  the  maximum  ebb  velocity  to  occur  less  than  three  hours 
before  the  time  of  local  low  water.  In  a  very  long  tidal  river,  the  strength  of  flood 
or  ebb  would  occur  almost  as  late  as  the  time  of  local  high  or  low  water.  In  streams 
of  the  kind  here  considered,  the  range  of  tide  may  increase  somewhat  in  going  up 
stream  provided  the  cross-section  diminished  gradually.  If,  however,  piers  or  bridges 
interfere  seriously  with  the  flow  of  tide  the  range  above  such  obstructions  will  be 
decreased,  and  as  a  consequence  the  tidal  volume  entering  a  river  so  obstructed  will 
be  diminished.    Suitable  dredging  will  increase  the  range  of  tide. 

The  range  of  tide  at  Passaic  Light,  Newark  bay,  is  4.7  feet;  at  Newark  it  is  5.0 
feet  and  at  Passaic  about  3  feet. 

The  range  of  tide  at  Sandy  Hook  is  4.7  feet;  Keyport,  Raritan  bay  is  5.3  feet;  at 
South  Amboy,  Raritan  river,  5.3  feet;  at  New  Brunswick  6.0  feet.  The  range  of  tide 
at  the  mouth  of  the  Rahway  river  is  5.0  feet;  at  the  mouth  of  Newtown  Creek  4.0 
feet;  and  at  the  mouth  of  the  Bronx  river  7.1  feet. 

Jamaica  bay  is  a  tidal  reservoir  connected  with  the  ocean  by  Rockaway  inlet.  The 
tidal  currents  through  this  inlet  are  hydraulic,  the  greatest  velocity  occurring  when 
the  bay  is  being  filled  or  emptied  most  rapidly,  or  about  three  hours  before  high  or 
low  water  in  Jamaica  bay.  The  considerable  tidal  area  of  the  bay  necessitates  rather 
strong  currents  through  the  inlet,  and  the  erosion  due  to  these  produce  a  depth  as 
great  as  50  feet  just  west  of  Rockaway  Beach. 

The  theoretical  velocity  for  a  section  extending  from  Barren  Island  to  the  north- 
ern coast  of  Rockaway  Beach  is, 

Area  of  bay  above  cross-section  at  H.  T.  L.  stage     /  rate  of  rise  and  fall 


Area  of  cross-section  at  half-tide  level  stage  \  of  surface  of  the  bay. 

Suppose  the  level  of  the  bay  as  a  whole  rises  and  falls  4  feet.  The  interval  of 
time  between  high  and  low  water  is  approximately  6  lunar  hours,  or  22,357  ordinary 
seconds.  Therefore  the  average  rate  of  rise  or  fall  per  second  is  4-=-22,357  foot.  The 
tide  curve  being  approximately  a  sine  curve,  the  maximum  rate  will  be  the  average 
rate  multiplied  by  "f"  or  1.5708. 

The  area  of  Jamaica  bay  and  tidal  tributaries  is  19.275  square  statute  miles 

(=537,356,160  square  feet),  at  mean  sea  level.   The  cross-section  from  Barren  Island 

to  the  northern  shore  of  Rockaway  Beach  is,  at  the  time  of  mean  sea  level,  79,425 

square  feet,  the  width  being  3,177  feet  and  the  average  depth  25  feet. 

.'.537,356,160  4 

oc  otr„  X  1.5  (Uo 


79,425  22,357 

=1.9014  feet  per  second,  or  1.1258  knots  per  hour,  for  the  cross-sectional  velocity 
at  the  time  of  the  strength  of  flood  or  ebb.  In  the  center  of  the  channel  the  velocity 
will  be  greater  than  this,  while  along  the  shores  it  will  be  less. 

A  few  observations  made  in  1877  near  this  cross-section  give  a  surface  velocity 
at  the  center  of  stream. 

Strength  of  flood,  1.9  knots. 
Strength  of  ebb,  2.4  knots. 


566         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


Shrewsbury  river  communicates  with  the  waters  inside  of  Sandy  Hook  through 
a  narrow  passageway.  As  a  result  the  range  of  tide  in  the  broad  portion  of  the  river 
is  considerably  smaller  than  the  range  around  Sandy  Hook,  and  the  time  of  tide  is 
considerably  later.  A  deepening  of  the  passageway  would  cause  a  greater  rise  and 
fall  of  the  water  in  the  broad  portion  of  the  river  and  so  increase  the  tidal  volume 
entering  and  leaving  the  river.  It  would  also  accelerate  the  time  of  the  occurrence  of 
the  tide.  The  flow  through  the  passageway  is  nearly  hydraulic ;  i.  e.,  the  water  flows 
towards  the  inner  or  outer  body  according  to  which  is  for  the  time  being  the  lower. 

Gowanus  Channel  is  so  situated  that  the  tidal  flow  must  be  very  small.  The 
volume  of  water  which  enters  upon  a  flood  tide  or  leaves  upon  an  ebb  tide  will  be 
the  area  of  this  canal  multiplied  by  the  range  of  tide  which  is  practically  the 
same  as  the  range  at  Governor's  Island.  The  length  of  the  canal  (and  its  branches) 
above  Hamilton  avenue  is  8,250  feet.  This  implies  a  cross-sectional  velocity  of 
2.55* 

3 — re — ,  , '     .. , — \  7  feet  per  second  at  the  time  of  strength  of  flood  or  ebb.    For  a 

depth  at  half-tide  level         ^  b 

depth  of  10f  feet  this  would  be  0.255  foot  per  second,  and  for  a  depth  of  5  feet,  0.510 
foot  per  second.  Near  the  head  of  the  canal,  or  of  any  branch  of  the  canal,  the 
velocity  from  the  tide  is  practically  zero.  The  above  computation  relates  to  a  cross- 
section  of  ordinary  size  at  or  near  Hamilton  avenue. 

5.  Is  there  a  discharge  of  water  through  the  East  river  and  New  York  bay  from 
Long  Island  sound  to  the  sea,  and  if  so,  how  great  is  it  under  (a)  usual  conditions 
and  (b)  conditions  which  are  unfavorable  to  the  discharge  of  water  from  the  harbor? 

There  is  doubtless  a  small  resultant  flow  through  East  river  from  Long  Island 
sound  into  Upper  New  York  bay,  although  observations  do  not  conclusively  show  it. 
As  already  stated  the  flow  through  East  river  is  chiefly  hydraulic,  the  water  flowing 
always  toward  that  body  which  is  the  lower  for  the  time  being. 

Now  the  greatest  velocity  possible  in  an  open  channel  will  be  found  where  the 
cross-section  has  the  least  area.  In  case  of  the  East  river  this  section  extends  be- 
tween Astoria  and  Ward's  Island.   The  greatest  possible  velocity  will  be 


v=V2g  (fc-fc,)  (1) 

where  £„  denote  the  heights  of  the  surface  of  the  two  bodies  above  half -tide  level. 
If  the  channel  have  a  sensible  length,  say  more  than  a  few  hundred  feet,  the  velocity 
at  the  region  where  it  is  greatest  will  be  given  by  the  formula 

2g  (£,-£„) 


1+r  P  t  (2) 

a 

where  V  is  an  empirical  abstract  number  equal  to  about  0.007565,  P  the  wetted 
perimeter,  Q,  the  area  of  the  cross  section,  I  the  length  of  the  channel.   If  the  channel 

=  mean  velocity  at  outer  end. 


Area  X  duration 
Tidal  prism  =  length  X  width  X  range  of  tide. 
Area  =  width  X  depth. 

y=  Leng^hXra^e_     Duration  =  6  ,unar  hour(J  m  22357  fleconda> 

Depth  X  duration 

Max  V  =  -i-  ( Lenetn  X  range\  =  \  X  8250  X  4  .4  =         2  .55 

2  \  Half-tide  depth/     22357   X  depth     Half -tide  depth. 

tThis  depth  is  used  for  purposes  of  illustration,  the  correct  depth  not  being  known. 


CORRESPONDENCE — TIDAL  FLOW 


567 


have  a  gradually  varying  cross-section,  the  velocity  at  the  region  where  it  is  greatest 
will  be  v  where 


Here  the  subscript  x  is  supposed  to  refer  to  the  portion  of  the  channel  where  the 
smallest  cross-section,  and  so  the  greatest  velocity,  occurs.  The  subscripts  2,  s,  ... 
refer  to  other  portions  of  the  channel. 

The  mean  range  of  tide  at  Willets  Point  is  7.2  feet;  the  tidal  hour  of  the  semi- 
daily  wave  is  III. 9.  The  corresponding  quantities  for  Governor's  Island  are  4.4  and 
XII. 8.  By  combining  two  sine  curves  (Coast  and  Geodetic  Survey  Report  for  1907, 
pp.  328,  542),  these  values  give  X.9  as  the  time  of  the  greatest  eastward  downward 
slope  throughout  East  river,  and  4.3  feet  as  the  difference  in  head  at  this  time.  The 
time  of  the  greatest  slope  in  the  opposite  direction  is  X.9 — 6=IV.9.  These  times 
agree  approximately  with  the  times  of  the  strength  of  flood  and  ebb  throughout  the 
greater  portion  of  East  river,  observation  making  the  latter  XI.3  and  V.3. 

The  formula 


feet  per  second,  a  value  much  in  excess  of  the  measured  value.  This  shows  that  the 
resistance  factor  in  the  denominator  of  the  more  general  expression  for  v2  is  several 
times  unity. 

If  the  East  river  were  very  much  deeper  and  broader  than  it  now  is  in  all  portions 
of  its  course  except  in  the  Hell  Gate,  then  the  quantity  of  water  passing  through  Hell 
Gate  during  a  flood  or  ebb  period  of  6  lunar  hours  would  depend  upon  the  area  of  the 
flood  or  ebb  cross-section.  The  rate  of  the  flood  and  ebb  streams  at  the  times  of  their 
maximum  values  being,  upon  the  above  hypothesis,  sensibly  the  same,  the  rate  of  dis- 
charge in  the  two  directions  at  these  times  will  be  proportional  to  the  flood  and  ebb 
sections.  In  the  Hell  Gate  as  it  exists  the  area  of  the  section  for  the  east-going  stream 
averages  less  than  the  area  of  the  section  for  the  west-going  stream. 

The  high  water  tidal  hour  between  Astoria  and  Ward's  Island  is  about  III. 5. 
The  time  of  attaining  the  following  half-tide  level  will  be  III.5+3=VL5.  This 
shows  that  when  the  west-going  stream  (ebb)  has  its  maximum  value  (viz.,  at  V.3) 
the  water  in  the  Hell  Gate  is  falling  but  lacks  1.2  lunar  hours  (VI. 5— V.3)  of  reach- 
ing its  half-tide  level  stage.  The  range  of  tide  here  being  5.6  feet,  the  surface  will 
then  be  2.8  sine  (1.2x30)  =2.8  sine  36°=1.646  feet  above  its  half-tide  level.  These 
results  are  in  general  accord  with  those  shown  in  Diagram  C,  page  416,  Coast  and 
Geodetic  Survey  Report  for  1886.  If  the  half-tide  depth  in  this  locality  were  35 
feet,  it  might  be  inferred  that  the  rate  of  westward  discharge  at  the  time  of  strength 
of  current  would  be  to  the  rate  of  eastward  as  35+1.646:35—1.646,  or  about  1.1. 
Considering  a  whole  flood  or  ebb  this  ratio  would  be  not  far  from  1.05.  But  an  in- 
crease in  the  cross-section  of  the  Hell  Gate  does  not  involve  a  proportional  increase 

•Correctly  written 


2<7  (C,-C„) 


(3) 


v  =  V2  g  (t,  —  Z„) 


becomes 


«=8.0215V£—  £„=8.0215V4.3=8.0215X2.0736=16.63 


V»  - 


(3) 


568 


DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


in  the  quantity  of  water  transmitted.  For,  as  noted  above,  the  resistance  factor,  in 
the  denominator  of  (3),  due  to  the  friction  in  the  river  bed  is  responsible  for  the 
diminution  of  the  velocity  from  its  theoretical  value 

V2  g  (£,-*„) 

to  its  observed  value.  This  factor  increases  or  decreases  if  the  size  of  the  cross- 
section  at  the  Hell  Gate  (&i)  increases  or  decreases,  62  2,  s,  etc.,  remaining  the 
same.  Because  this  factor  greatly  exceeds  unity  it  seems  probable  that  the  volume 
transmitted  westerly  can  be  not  more  than  1  or  2  per  cent,  greater  than  the  volume 
transmitted  easterly.  It  almost  certainly  plays  no  important  part  in  flushing  out 
New  York  harbor. 

6.  To  what  extent  have  changes  in  the  depth,  width  and  location  of  the  channels 
and  the  construction  of  islands  and  bulkheads  affected  the  flow  of  water  through 
the  harbor? 

Owing  to  the  fact  that  the  tidal  areas  such  as  the  Upper  bay,  Hudson  river,  and 
Newark  bay  are  large  in  comparison  with  any  reclaimed  areas,  it  follows  that  the 
flow  in  or  out  of  the  harbor  can  scarcely  be  sensibly  affected  because  of  the  tidal  area 
already  lost.  Of  course  a  sufficient  extension  of  the  piers  into  the  Hudson  river 
would  reduce  the  amount  of  tide  water  passing  up  and  down  that  river.  However, 
neither  the  reclamation  of  shoal  areas  nor  the  extension  of  the  piers  into  the  Hudson 
seems,  up  to  the  present  time,  to  have  sensibly  interfered  with  the  tide.  For  in- 
stance, the  mean  range  of  tide  at  Dobbs  Ferry,  determined  from  observations  made 
in  the  years  1856,  1858,  1885,  1886  and  1900,  has  the  values  3.71,  3.69,  3.58,  3.60  and 
3.66  feet,  respectively. 

The  dredging  of  the  channels  in  the  Lower  bay  has  probably  produced  no  sensible 
alteration  in  the  general  circulation  of  the  harbor. 

7.  In  general  terms,  what  are  the  controlling  factors  which  affect  the  flow  of 
water  in  and  out  of  New  York  harbor?  Especially  what  is  the  effect  produced  by 
the  wind? 

The  variability  of  the  drainage  discharge  from  month  to  month  has  been  con- 
sidered in  answer  to  question  No.  1. 

The  variability  of  the  quantity  of  other  water  entering  or  leaving  the  harbor 
may  be  either  regular,  that  is,  dependent  upon  the  known  or  predictable  variation  in 
the  rise  and  fall  of  the  tide;  or  it  may  be  irregular,  that  is,  dependent  upon  the 
effects  of  the  wind. 

The  mean  range  of  tide  at  Governor's  Island  is  4.4  feet,  the  spring  range  5.3  feet 
and  the  neap  range  3.4  feet.  The  spring  tides  occur  about  25.6  hours  after  new  moon 
or  full  moon  and  neap  tides  as  many  hours  after  the  first  or  third  quarter  of  the 
moon.  The  perigean  range  of  the  tide  is  5.3  feet  and  occurs  about  37.8  hours  after 
the  moon  is  in  perigee;  the  apogean  range  is  3.8  feet  and  occurs  37.8  hours  after  the 
moon  is  in  apogee.  At  the  time  of  the  moon's  extreme  fortnightly  declination  north 
or  south  from  the  celestial  equator,  the  difference  in  height  between  two  consecutive 
high  waters  is  1.0  foot  and  between  two  consecutive  low  waters  0.3  foot. 

The  above  figures  indicate  the  average  value  of  the  principal  variations  in  the 
tide  at  Governor's  Island. 

Of  course,  if  the  new  or  full  moon  happens  to  occur  on  the  day  when  the  moon  is 
in  perigee,  the  ranges  of  tide  of  that  day  will  exceed  the  ordinary  value  of  spring 


CORRESPONDENCE— TIDAL  FLOW 


569 


ranges  by  a  quantity  about  equal  to  the  excess  of  the  perigean  range  above  the  mean 
range. 

The  ordinary  extreme  value  of  the  annual  fluctuation  of  the  surface  of  the  Upper 
bay  due  to  the  winds  is  about  4  feet.  On  one  or  more  days  of  each  winter  it  is  usual 
for  the  winds  to  produce  an  extreme  depression  in  the  water's  surface  of  about  2  feet 
below  the  regular  tidal,  or  predictable,  height,  that  it,  below  the  surface  as  influ- 
enced by  the  tides  alone.  Some  time  during  each  year  the  winds  ordinarily  produce 
an  extreme  elevation  in  the  surface  of  about  2  feet  above  the  regular  tidal,  or  pre- 
dictable, height. 

8.  Would  it  be  feasible  to  establish  a  system  of  gauges  in  and  about  New  York 
which  would  permit  the  city  to  make  a  calculation  at  any  time  of  the  quantities  of 
water  being  carried  in  the  main  tidal  currents? 

It  might  be  well  to  establish  and  maintain  a  gauge  upon  the  Hudson  river  some- 
where above  Manhattan  Island,  say,  at  Dobbs  Ferry  or  at  some  point  a  few  miles 
further  north.  If  the  range  of  tide  were  there  found  to  diminish  from  year  to  year 
it  would  indicate  that  the  tidal  movements  were  being  reduced  because  of  the  in- 
croachment  of  the  piers  and  bulkheads  from  the  New  York  and  New  Jersey  sides  of 
the  river.  For  similar  reasons  gauges  might  be  maintained,  one  on  Newark  bay,  say 
at  Passaic  Light,  one  on  the  Passaic  river  near  Paterson,  and  one  on  the  Hacken- 
sack  river  near  Hackensack. 

9.  What  is  the  average,  the  maximum  and  minimum  velocities  in  each  direction 
of  the  currents  at  the  principal  points  in  New  York  harbor  taken  at  the  time  when 
each  current  is  strongest?  That  is,  how  do  the  velocities  vary  with  different  tides 
through  the  year? 

Answer  included  under  answers  to  Nos.  1  to  4  and  No.  7. 

10.  What  is  the  distance  that  water  moves  in  different  parts  of  the  harbor 
through  a  complete  tide,  from  high  water  to  high  water  and  from  low  water  to  low 
water  as  shown  by  floats,  and  what  is  the  net  movement  of  the  water,  starting  from 
different  points,  towards  the  sea? 

The  rate  of  movement  of  the  water  towards  the  sea  (due  to  fresh  water  above  the 
point  considered)  can  be  ascertained  by  dividing  the  fresh  water  discharge  per 
second  or  per  6  lunar  hours  by  the  area  cross-section  through  the  given  point.  For 
instance,  through  the  Narrows  the  average  cross-sectional  velocity  q>f  the  discharge 
is  26,442-^322,080=0.0821  foot  per  second.  It  is  least  in  August  and  greatest  in 
April. 

Between  Battery  Place  and  Communipaw  Ferry  the  cross-sectional  velocity  of 
discharge  is  24,314-^180,000=0.1351  foot  per  second  on  an  average  throughout  the 
year. 

The  distance  through  which  the  water  moves  in  a  given  time  or  through  a  com- 
plete tide  can  be  ascertained  as  explained  in  the  answer  to  No.  2. 

Free  floats  have  been  used  in  a  few  cases.  A  blue  print*  showing  the  courses  of 
the  floats  in  East  river  together  with  an  explanatory  table  is  given  below. 

The  copy  of  the  first  Report  of  the  New  York  Bay  Pollution  Commission  is 
returned,  as  requested. 

Respectfully  yours, 

F.  W.  Perkins, 

Act'g  Superintendent. 
1  enclosure.  A.  B. 

*Not  reproduced. 


570 


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574         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

The  letter  consists  largely  of  a  mathematical  and  theoretical  discussion  of  the 
flow  of  water,  and  is  based  largely  upon  the  methods  of  studying  the  flow  of  large 
streams  of  water  which  engineers  and  physicists  customarily  employ  where  gaugings 
and  current  observations  are  not  available. 

One  of  the  results  of  the  study  was  to  revise  the  Survey's  former  estimates  of  the 
flow  of  water  in  the  Lower  East  river  so  that  instead  of  a  large  excess  which  might 
be  utilized  for  the  mechanical  removal  of  sewage  from  the  Lower  East  river,  there 
appeared  to  be  little  or  no  preponderance  of  discharge  in  one  direction  over  the  reverse 
flow. 

After  giving  considerable  study  to  Exhibit  IV,  it  became  necessary  for  the  Com- 
mission to  ask  the  Survey  to  clarify  certain  matters  relating  to  the  Lower  East  river 
and  the  question  of  a  preponderance  of  flow  in  the  Lower  East  river  was  again  re- 
ferred to  in  a  letter  dated  January  21,  1909,  and  given  here  as  Exhibit  V. 

EXHIBIT  V 

New  York,  January  21,  1909. 

Mr.  F.  W.  Perkins,  Acting  Sup't, 

U.  S.  Coast  and  Geodetic  Survey, 
Washington,  D.  C. 

Sir:  With  reference  to  your  letter  of  August  14,  1908,  regarding  the  tidal 
phenomena  of  the  waters  of  New  York  harbor,  there  is  one  point  we  have  not  been 
able  to  reconcile  with  other  data  at  hand :  In  connection  with  the  resultant  flow  from 
Long  Island  Sound  to  the  Upper  Bay  you  state  (p.  23)  :  "There  is  doubtless  a  small 
resultant  flow  through  East  river  *  *  *  although  observations  do  not  conclusively 
show  it.  As  already  stated,  the  flow  through  East  river  is  chiefly  hydraulic  *  *  *." 
You  then  deduce  a  formula  (3)  for  the  velocity  at  Hell  Gate,  the  resistance  factor  in 
the  denominator  of  which  accounts  for  the  variation  from  the  theoretical  velocity, 
and  say  that,  "Because  this  factor  greatly  exceeds  unity  it  seems  probable  that  the 
volume  transmitted  westerly  can  be  not  more  than  1  or  2  per  cent,  greater  than  the 
volume  transmitted  easterly"  (p.  27). 

This  theoretical  deduction  is  not  entirely  clear  to  us,  as  the  increase  in  cross- 
sectional  area  during  the  ebb,  on  which  the  discharge  is  largely  dependent,  is  not 
known  and  may  be  large.  But  after  all,  the  actual  gagings  that  have  been  made 
would  appear  to  have  more  weight  in  any  conclusion  than  any  deductions  based  upon 
theory  alone,  and  we  would  therefore  be  glad  to  learn : 

1.  Whether  there  are  other  gagings  or  considerations  not  known  to  us  that  would 
invalidate  the  results  obtained. 

2.  How  the  gagings  made  by  the  U.  S.  C.  &  G.  C.  at  19th  street  in  1885  (Rep.  1887, 
App.  15,  p.  305),  and  at  23d  Street  in  1886  (Rep.  1886,  App.  13,  p.  424),  can  be  recon- 
ciled with  the  conclusion  that  the  preponderance  of  the  ebb  flow  is  not  over  1  per  cent. 

We  would  call  attention  to  the  explanation  of  a  substantial  preponderance  in 


CORRESPONDENCE— TIDAL  FLOAT 


575 


Rep.  18S6,  App.  13,  p.  421,  where  it  is  stated  that  "there  are  3y2  feet  more  water  over 
the  sill  of  Hell  Gate  when  the  eastern  slope  is  at  maximum,"  etc.,  and  to  p.  429,  where 
certain  estimates  are  given  of  this  excess. 

We  would  also  refer  to  a  letter  written  by  Mr.  O.  H.  Tittmann,  Superintendent 
U.  S.  C.  &  G.  S.,  June  1,  1903,  to  Mr.  J.  A.  Lebkuecher,  Chairman  Passaic  Valley 
Sewerage  Commissioners,  a  copy  of  which  was  furnished  one  of  our  Commission,  in 
which  he  estimates  the : 

Westerly  Flow  at  19th  Street  at  4,454,937,257  cubic  feet. 

Easterly  Flow  at  19th  Street  at  4,007,175,676  cubic  feet, 
adding  that  "The  volume  of  discharge  given  above  should  supersede  the  data  previ- 
ously furnished." 

In  short,  from  every  source  of  information  available,  including  the  opinion  of 
pilots  and  the  view  which  is  understood  to  be  held  by  members  of  the  New  York  Har- 
bor Line  Board,  the  preponderance  of  a  southward-moving  current  of,  at  least,  10  per 
cent.,  and  possibly  more  is  indicated. 

Thanking  you  again  for  the  assistance  you  have  already  rendered  us  and  hoping 
that  you  may  find  it  convenient  to  throw  light  on  the  above  perplexing  question,  I 
remain, 

Very  sincerely, 

George  A.  Sopee, 

President. 

The  Commission's  questions  concerning  the  resultant  flow  in  the  East  river,  as 
stated  in  Exhibit  V,  were  answered  by  the  Survey  in  a  letter  dated  February  6,  1909, 
and  given  here  as  Exhibit  VI. 

EXHIBIT  VI 

Washington,  D.  C,  February  6,  1909. 

Mb.  George  A.  Soper, 

President,  Metropolitan  Sewerage  Commission  of  New  York. 

Sir:  Your  letter  of  the  21st  ultimo,  concerning  the  resultant  flow  in  East  river 
was  duly  received. 

Before  going  into  numerical  details,  it  may  be  noted  that  the  current  observa- 
tions mentioned  in  your  letter,  viz.,  those  plotted  upon  p.  423,  Report  for  1886,  and 
upon  plate  opposite  p.  305,  Report  for  1887,  were  continued  for  too  short  a  period  to 
determine  beyond  question  the  net  or  resultant  flow  of  East  river.  These  plottings 
indicate  the  existence  of  irregularities,  or  non-periodic  features,  in  the  current  while 
the  observations  were  being  taken.  Upon  the  page  referred  to  above  in  the  Report  for 
1886,  the  plotted  curve  shows  that  at  Old  Ferry  Point  the  east-going  stream  is  much 
stronger  than  the  west-going,  a  fact  which  taken  by  itself  would  indicate  a  net  dis- 
charge in  the  easterly  direction  (or  into  the  Sound),  instead  of  a  westerly  discharge. 
This  will  be  partially  offset  by  the  fact  that  at  Old  Ferry  Point  the  maximum  velocity 
of  the  east-going  stream  occurs  about  an  hour  after  the  time  of  local  low  water  and 
that  of  the  west-going  stream  about  an  hour  after  the  time  of  local  high  water.  But 
it  is  quite  doubtful  if  the  excess  in  cross-section  for  the  west-going  stream  over  that 


576         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


for  the  east-going  stream  would  be  sufficient  to  account  for  the  observed  excess  of 
the  eastward  velocity  over  the  westward  velocity  for  the  particular  day  of  the 

observations. 

Further  evidence  that  the  eastward  velocity  at  Old  Ferry  Point  exceeds  the  west- 
ward can  be  seen  upon  consulting  the  curves  plotted  upon  cross-section  paper*  from 
observations  taken  in  August,  1885,  and  which  are  sent  you  herewith. 

RATIO  OF  CROSS  SECTIONS  FOR  THE  FLOOD  AND  EBB  STREAMS  AT  THE 

HELL  GATE. 

On  p.  26  of  the  letter  from  this  office  dated  August  14,  1908,  it  is  pointed  out 
that  at  hour  V.3,  or  the  time  of  the  maximum  velocity  of  the  west-going  stream,  the 
depth  of  water  in  the  Hell  Gate  is  1.646  feet  more  than  its  mean  depth  and  at  XI.3,  or 
the  time  of  the  maximum  velocity  of  the  east-going  stream  it  is  1.646  feet  less  than 
the  mean.   The  mean  depth  is  about  35  feet. 

It  was  also  noted  that  the  ratio  of  the  ebb  to  the  flood  section  could  not  be  as 
-  [  ■  ]_  646 

great  as  0_    .,  '       or  1.1,  but  would  probably  be  about  1.05.    It  seems  best  to  here 
35 — 1 . 646 

actually  compute  this  ratio. 

The  ratio  in  question  is 


where  t,  in  the  numerator,  varies  from  V.3— 3  to  V.3-f-3  or  30*  from  69°  to  249° ;  and, 
in  the  denominator,  from  XI.3— 3  to  XI.3+3  or  30*  from  249°  to  429°=69°. 

2.8  is  the  amplitude  (semirange)  of  the  tide  in  the  Hell  Gate  and  III. 5  the  high 
water  tidal  hour;  105o=30°XHL5. 

The  above  fraction  may  be  written 


r  37=249° 

/cos    (x— 159°)  (35+2.8  cos  (x— 105°)  dx 
x=69°  

y*j?=69° 
cos    (x— 339°)  (35+2.8  cos  (x— 105°)  d  x 
x=249° 


70+2.8  /  (cos2  x  cos  159°  cos  105°+sin2  x  sin  159°  sin  105°— 1/2  sin  2  x  sin  84°)  d  x 


70+2.8  /  (cos2  x  cos  339°  cos  105°+sin2  x  sin  339°  sin  105°+y2  sin  2  x  sin  84°)  dx 
J  #=249° 


Average  value  of  cos  (30*— 159°)  [35+2.8  cos  (30*— 105°)] 
Average  value  of  cos  (30*— 339°)  [35+2.8  cos  (30*— 105°)] 


where  x  is  written  for  30*. 
This  equals 


/\z=249° 

70+2.8 /cos    (x— 159°)  cos  (x— 105°)  dx 

J  a?=69° 


*Not  reproduced. 


CORRESPONDENCE— TIDAL  FLOW 


577 


70+2.8 


fx- 


=249° 
24163 

x=69° 


cos  2  x +1 


+.34616 


1 — cos  2  x 


.49726  sin  2  x)  d  x 


70+2.8  / ( 


=69c 


cos  2  #+1 


.24163 


.34616 


1 — cos  2  a? 


f  .49726  sin  2  a?)  da? 


70+2.8  .24163 

l-x=69c 


x=249 
*=249°  /  sin  2x  x 


+  T) +.34616 


(f 


sin  2  a? 


+  .24863  cos  2  a; 


70-2.8 


a?=69° 
.24163 
-#=249° 

70+2.8 


+ 


-#=249° 
(.29390.* 
-x=69° 


|-)  +.34616  (■ 


x 


sin  2  a? 


+  .24863  cos  2  a? 


0.02613  sin  2  #+.24863  cos  2  a;) 


—x- 


70-2.8 


=69c 


(.29390  a;  —  0.02613  sin  2  a?+.24863  cos  2  a?) 
-x=249° 


70— 2.8X-29390 


5.585 


=1.077 


70+2.8X-29390  *  67.415 
This,  then,  is,  by  calculation,  the  ratio  of  the  ebb-stream  section  to  the  flood- 
stream  section  at  the  Hell  Gate  when  the  entire  tidal  period  is  considered.  If  the 
flood  and  ebb  streams  were  here  equally  strong  it  would  indicate  a  westerly  flow 
about  8  per  cent,  greater  than  the  easterly  flow.  But  the  few  observations  which  have 
been  made  in  the  immediate  locality  indicate  that  the  east-going  stream  is  greater 
than  the  west-going,  and  so  it  is  not  safe  to  infer  from  the  above  that  the  westerly 
discharge  through  the  Hell  Gate  exceeds  the  easterly. 

THE  LENGTH  OF  THE  EAST  RIVER  AN  IMPORTANT  FACTOR 

Since  the  tidal  rise  and  fall  in  the  Upper  Bay  and  in  Long  Island  sound  is  nearly 
harmonic  in  time  (i.  e.,  it  nearly  obeys  the  law  of  sine  or  cosine  of  a  time  angle)  and 
since  the  current  in  East  river  is  nearly  hydraulic,  it  follows  that  the  velocity  set  up 
in  East  river,  taken  as  a  whole,  should  be  the  same  upon  the  flood  as  upon  the  ebb. 
In  other  words,  the  difference  in  head  will  be  the  same  in  like  phases  of  the  two 
streams.  But  formula  (3),  p.  24,*  shows  that  when  resistance  is  taken  into  account, 
the  velocity,  where  greatest,  depends  chiefly  upon  the  fact  that  East  river  has  con- 
siderable length;  for,  if  its  length  were  only  a  few  hundred  feet,  the  maximum 
velocity  would  be  as  indicated  upon  p.  25,  viz.,  16.63  feet  per  second. 

The  following  rough  computation  of  the  resistance  will  show  that  the  denomin- 
ator in  (2)  or  (3)  is  considerably  greater  than  unity. 

From  Throgs  Neck  to  the  western  side  of  Governor's  Island  is  17  statute  miles 
=89,760  feet.    The  average  depth  is  about  40  feet.    These  estimates  make 


and  so  putting  V  =  0.007565, 


L  =  89>76°;|-  =  io-; 


1+0.007565  X  2244 
=  1  +  1.70  =  2.70 


hour. 


v  =  16.63      V2.70  =  16.63  X  .6085  ==  10.12  feet  per  second  =  5.99  knots  per 


•Page  567,  this  report. 


578         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


This  is  not  greatly  in  excess  of  actual  ordinary  maximum  current  in  the  Hell 
Gate.  The  above  rough  computation  shows  that  the  velocity  is  kept  down  to  that 
actually  occurring  by  the  rtciistance  due  to  the  bed  and  banks  of  East  river.  The 
resistance  occurs,  of  course,  in  varying  amounts  in  different  portions  of  the  river. 
The  computation  is  for  a  uniform  channel.  The  actual  channel  would  doubtless  offer 
greater  resistance  than  the  one  here  assumed  because  of  the  bends  and  sudden 
changes  in  cross-section. 

IN  THE  WESTERN  END  OF  EAST  RIVER  THE  FLOOD  STREAM  HAS  THE 
GREATER  CROSS-SECTION,  IN  THE  EASTERN  END  OF  THIS  RIVER, 
THE  EBB  OR  WEST-GOING  STREAM  HAS  THE  GREATEST  CROSS- 
SECTION. 

The  Greenwich  lunar  times  of  high  and  low  water  (tidal  hours)  at  Governor's 
Island  are  XII. 73  and  VI. 95,  respectively,  same  quantities  at  Willet's  Point  are  III. 69 
and  X.10.  The  time  of  the  maximum  east-going  stream  is  X.5  at  Throgs  Neck  and 
XII  near  the  western  side  of  Governor's  Island.  But  the  time  for  greater  portion  of 
the  river  falls  between  XI  and  XI. 5,  and  has  been  taken  as  XI. 3.  (See  Figs.  11  and 
13,  opp.  p.  356,  Coast  and  Geodetic  Survey  Report  for  1907.)  The  times  of  the 
west-going  stream  are  the  above  diminished  by  6  hours.  Hence,  the  maximum  value 
of  the  west-going  stream  at  Throgs  Neck  follows  local  high  water  by  only  IV.5 — III. 69 
=0.8  hour.  The  maximum  value  of  the  east-going  stream  at  Governor's  Island  follows 
local  high  water  by  only  XII. 73 — XII=0.7  hour. 

The  streams  thus  attaining  their  maximum  values  at  nearly  the  times  of  local 
high  water,  it  follows  that  the  west-going  stream  at  Throgs  Neck  has  a  considerably 
greater  cross-section  than  the  east-going,  while  the  reverse  is  true  for  the  Governor's 
Island  end. 

The  point  in  East  River  where  the  maximum  streams  occur  at  the  time  of  local 
half-tide  level  is  about  the  middle  of  Blackwell's  Island.  Westward  from  this  point 
the  east-going  stream  has  the  greater  cross-section  and  eastward  from  this  point  the 
reverse  is  the  case. 

Currents  observed  at  21  stations  where  results  are  available  between  Blackwell's 
Island  Light  and  Throgs  Neck  show  the  westerly  velocity  to  be  only  about  0.77  times 
the  easterly  velocity.   The  range  of  tide  over  this  region  being  6.8  feet  and  the  depth  40, 

the  ratio  of  sections  will  be  ^  ,  ^  t  —0.84.    This  ratio  compared  with  that  obtained 

40+3.4 

from  observation  indicates  easterly  resultant  flow.  The  excess  of  the  easterly  over 
the  westerly  velocity  is  apparent  upon  consulting  the  blue  prints*  of  the  plotted  ob- 
served velocities. 

Current  observations  taken  between  the  southern  end  of  Blackwell's  Island  and 
Wallabout  Bay  show,  on  an  average,  no  difference  between  the  velocities  of  the  east- 
going  and  west-going  streams.  At  the  middle  of  this  reach  the  times  of  half-tide  level 
are  X.9  and  IV.9.  The  times  of  the  east-going  and  west-going  streams  are  XI.3  and 
V.3  respectively.  Hence,  in  this  reach  where  the  times  of  half-tide  level  about  coin- 
cide with  the  times  of  maximum  current  (the  locality  therefore  being  one  where  the 
two  streams  have  nearly  equal  cross-sections)  the  two  streams  have  practically  the 
same  velocities.  The  observed  velocity  of  the  west-going  stream  comes  out  from  18 
stations  as  1.00  times  that  of  the  east-going.  This  indicates  that  a  trifle  more  water 
flows  easterly  than  westerly. 

*Not  reproduced. 


CORRESPONDENCE— TIDAL  FLOW 


579 


Between  the  Brooklyn  Bridge  and  Governor's  Island  the  velocity  of  west-going 
stream  is  for  17  stations  1.23  times  that  of  the  east-going.  Little  importance  should 
be  attached  to  this.  It  doubtless  shows  that  portions  of  the  fresh  surface  water  of 
the  Hudson  are  deflected  to  the  eastward  of  Governor's  Island  and  pass  out  through 
Buttermilk  Channel. 

The  two  stations  near  the  northern  end  of  Blackwell's  Island  at  which  several 
days'  continuous  observations  were  obtained,  and  for  which  blue  prints  are  furnished, 
show  the  velocities  of  the  two  streams  to  be  nearly  equal,  the  west-going  stream  being 
1.01  times  the  east-going.  Taking  6  stations  around  Blackwell's  Island  into  consider- 
ation, this  ratio  becomes  1.03.  Here  the  time  of  half-tide  level  almost  exactly  coin- 
cides with  the  time  of  the  maximum  flood  or  ebb  current.  This  fact  taken  in  con- 
nection with  the  current  observations  indicate  that  the  volumes  passing  each  way  are 
sensibly  equal,  the  west-going  being  1.03  times  the  east-going. 

CONCLUSIONS 

It  can  hardly  be  said  that  our  observations  upon  the  currents  indicate  a  net  dis- 
charge in  either  direction  through  the  Hell  Gate.  They  indicate  that,  as  a  rule,  the 
stream  having  the  larger  cross-section  has  the  smaller  velocity,  and  vice  versa,  thus 
leaving  the  question  of  the  amount  of  net  discharge  uncertain. 

Mitchell  in  his  early  determination  (Report  for  1871,  p.  131),  gives  for  the  vol- 
umes passing  through  East  River  at  Wall  Street  section:  Flood,  4,341,100,000  cubic 
feet;  ebb,  4,383,500,000  cubic  feet,  or  a  difference  of  only  1  per  cent.  See  also  pp. 
168-173,  Report  for  1876. 

Observations  indicate  that  for  sections  between  Wallabout  Bay  and  the  southern 
extremity  of  Blackwell's  Island  the  flood  volume  is  quite  as  great  as  the  ebb  volume 
(p.  8,*  this  letter). 

Observations  taken  between  Blackwell's  Island  light  and  Throgs  Neck  show  that 
the  flood  stream  is  decidedly  stronger  than  the  ebb.  A  rough  computation  (p.  7,f  this 
letter),  indicates  when  the  cross-section  of  the  two  streams  are  compared  there  can 
hardly  be  a  westerly  net  discharge  through  the  East  river. 

The  observations  around  Blackwell's  Island,  taken  by  themselves,  indicate  a  small 
net  westerly  discharge,  the  west-going  volume  being  about  1.03  times  the  east-going.  It 
seems  probable  that  this  item  is  more  important  in  deciding  the  question  than  any  one 
of  the  others  contained  in  this  letter. 

On  p.  422,  Report  for  1886,  Mitchell  says :  "From  Table  3,  and  the  Diagram  B 
that  illustrates  it,  one  may  estimate  for  the  point  intermediate  between  84th  street 
and  Polhemus  Dock  a  difference  of  Sy2  feet  between  the  stages  of  alternate  maximum 
slopes,  i.  e.,  there  are  3^2  feet  more  water  over  the  sill  of  Hell  Gate  when  the  western 
slope  is  at  maximum  than  there  is  when  the  eastern  slope  is  at  maximum.  We  have 
reiterated  the  foregoing  statement  because  it  is  the  keynote  of  our  theme  and  gives  no 
uncertain  sound." 

But  the  flow  through  East  river  will  not  vary  as  the  cross-section  at  Hell  Gate  of 
the  flood  or  ebb  stream.  For  it  is  evident  from  formula  (3),  p.  24,|  letter  of  Aug.  14, 
1908,  that  the  smaller  the  section  at  this  point,  the  other  sections  of  the  river  remain- 
ing as  before,  the  greater  must  be  the  velocity  there,  because  k,  or  the  distance  through 
the  "gate,"  is  a  small  fraction  of  l2,  l3,  etc.,  the  lengths  of  the  other  reaches  of  the 

*Page  577,  this  report.       fPage  577,  this  report.       JPage  567,  this  report. 


580         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


river.  As  the  third  and  subsequent  terms  of  the  denominator  of  (3)  become  the  im- 
portant terms,  the  velocity  v  at  the  Hell  Gate  varies  approximately  inversely  as  Si,  or 
the  section  at  that  place  varies.  But  the  cross-sections  for  the  other  and  longer  reaches, 
Si 2,  Si 3,  ...  are  larger  for  one  stream  than  for  the  other;  formula  (3)  shows  that, 
other  things  being  equal,  increases  in  such  sections  increase  the  velocity,  v,  through 
Six.  By  varying  the  cross-sections  for  the  varying  stages  of  the  tide,  and  by  giving 
them  proper  weights  in  the  denominator  of  formula  (3),  it  seems  quite  possible  that 
the  westward  velocity  through  the  Hell  Gate  may  so  fall  short  of  the  eastward  velocity 
that  the  ebb  volume  shall  exceed  the  flood  volume  by  only  a  small  amount,  although 
the  section  of  the  former  is  1.077  times  that  of  the  latter  (p.  4,  this  letter).  As  already 
stated,  observations  seem  to  indicate  that  the  ebb  velocities  here  are  somewhat  less 
than  the  flood  velocities. 

Attached  are  8  blue  prints  and  1  plotting  of  current  observations.* 

Respectfully  yours, 

O.  H.  Tittmann, 

Superintendent. 

*Not  reproduced. 


CORRESPONDENCE— TIDAL  FLOW 


581 


SECTION  II 

CORRESPONDENCE  RELATING  TO  NEW  ESTIMATES  OF  THE  FLOW  OF 

THE  EAST  RIVER 

It  having  come  to  the  knowledge  of  the  Commission  that  extensive  observations 
of  the  flow  of  the  East  river  at  Hell  Gate  had  been  made  by  the  Engineer  Depart- 
ment of  the  U.  S.  Army,  a  request  for  permission  to  utilize  these  data  was  made  to 
Colonel  William  M.  Black,  under  whose  direction  the  observations  had  been  prepared. 
The  data  had  not  hitherto  been  computed  to  show  the  total  volume  of  water  passing 
through  the  Lower  East  river,  the  object  of  the  studies  having  covered  another  scope 
relating  to  the  local  improvements  of  the  channels.  The  permission  was  granted  and 
the  Commission  undertook  to  re-estimate  the  flow  of  water  passing.  The  fundamental 
data  consisted  of  a  number  of  tide  gauge  records  covering  a  long  period  of  time  and 
co-related  in  part  with  current  observations  extending  over  a  briefer  interval.  When 
the  computations  were  completed  the  result  showed  a  considerable  excess  flow  of 
water  southward  through  the  East  river. 

The  matter  was  referred  by  the  Commission  to  the  Survey  in  a  letter  dated  May 
13,  1913,  with  the  request  that  the  Survey  give  the  estimate  a  critical  examination 
and  express  an  opinion  as  to  the  accuracy  of  the  results.  This  letter  is  here  given 
as  Exhibit  VII. 

EXHIBIT  VII 

New  York,  May  13,  1913. 

Prof.  O.  H.  Tittmann,  Director, 

U.  S.  Coast  &  Geodetic  Survey, 
Washington,  D.  C. 

Dear  Sir  :  Your  attention  is  invited  to  the  enclosed  statement  describing  studies 
made  partly  by  Colonel  William  M.  Black,  Corps  of  Engineers,  U.  S  Army,  and 
partly  by  this  Commission,  concerning  the  volumes  of  water  passing  through  the 
East  river  in  the  vicinity  of  Hell  Gate.  A  detailed  account  of  the  field  and  office 
methods  used  in  obtaining  these  results  will  be  found  in  Professional  Memoirs,  Corps 
of  Engineers,  U.  S.  A.,  for  May-June,  1913. 

This  Commission  would  value  your  critical  examination  of  this  study  and  an 
opinion  as  to  the  accuracy  of  the  results.  You  will  observe  that  the  results  appear  to 
confirm  the  figures  announced  by  Prof.  Henry  Mitchell  in  1886,  as  a  result  of  his 
studies,  and  that  they  do  not  agree  either  with  the  results  of  the  investigations  made 


582         DATA  RELATING  TO  THE  PROTECTION  OP  THE  HARBOR 


by  the  U.  S.  Coast  Survey  in  1908  and  transmitted  by  the  Survey  in  a  statement  to  this 
Commission  dated  August  14,  1908,  or  with  the  results  of  the  studies  made  by  Mr.  H. 
deB.  Parsons  of  this  Commission  and  described  in  the  April  number  of  the  Proceed- 
ings of  the  American  Society  of  Civil  Engineers. 

Very  sincerely, 

George  A.  Soper, 

President. 

The  report  on  the  computations  prepared  by  Ernest  F.  Robinson,  Assistant 
Engineer  on  the  Commission's  staff,  who  collected  the  original  data  under  the  direction 
of  Colonel  Black,  and  later  had  charge  of  the  computations  for  the  Commission,  dated 
May  1,  1913,  is  here  given  as  Exhibit  VIII. 

EXHIBIT  VIII 

May  1,  1913. 

Dr.  George  A.  Soper, 

President,  Metropolitan  Sewerage  Commission  of  New  York. 

Dear  Sir  :  I  have  the  honor  to  report  upon  an  investigation  of  the  ebb  excess  flow 
in  the  East  and  Harlem  rivers,  New  York  harbor. 

The  question  of  preponderance  of  flow  towards  New  York  bay  from  Long  Island 
sound  is  a  disputed  one.  It  was  first  investigated  by  Henry  Mitchell,  assistant,  U.  S. 
Coast  and  Geodetic  Survey,  in  1886.  In  his  report,  he  first  demonstrated  by  the  nature 
of  the  tidal  phenomena  at  either  entrance  to  the  harbor,  that  such  an  excess  should 
exist,  then  by  field  observations  he  established  its  magnitude,  as  about  400,000,000 
cubic  feet  in  each  tidal  cycle  of  12  lunar  hours  (12h.  25m.  solar  time). 

Since  the  publication  of  this  report  there  have  been  numerous  discussions  upon 
the  subject,  and  the  Coast  Survey  itself  has  rejected  this  figure  as  excessive,  substi- 
tuting a  value  of  *100,000,000  "or  less"  as  the  probable  excess.  Mr.  H.  deB.  Par- 
sons, of  the  Metropolitan  Sewerage  Commission,  recommends  a  figure  of  80,000,000 
cubic  feet  (Proc.  Am.  Soc.  C.  E.,  April,  1913,  page  715).  It  is  significant,  however, 
that  of  all  these  later  estimates,  not  one  is  based  upon  actual  field  observations. 

Professor  Mitchell's  theoretical  demonstration  was  extremely  simple,  and  admits 
no  doubt  that  such  excess  must  occur,  leaving  only  a  question  as  to  its  amount.  The 
range  of  tide  at  Throgs  Neck,  the  Long  Island  sound  entrance  to  the  harbor,  is  greater 
than  that  at  Sandy  Hook,  the  southern  entrance.  Furthermore,  the  tidal  wave,  in  its 
passage  through  the  sound,  is  delayed,  so  that  high  water  occurs  3!/2  hours  later  at 
Throgs  Neck  than  at  Sandy  Hook. 

Owing  to  the  difference  of  range,  the  tide  at  Sandy  Hook  does  not  rise  as  high  as 
that  at  Throgs  Neck,  neither  does  it  fall  so  low.  The  greatest  difference  of  level,  or 
slope,  on  the  northbound  tide,  occurs  about  iy2  hours  before  high  water  at  Sandy 

*Letter  of  Mr.  F.  W.  Perkins,  Acting  Supt.  to  Dr.  Soper,  President  Metropolitan  Sewerage  Commission,  Aug.  14, 
1908. 


CORRESPONDENCE— TIDAL  FLOW 


583 


Hook,  and  on  the  southbound  tide,  1  hour  after  high  water  at  Throgs  Neck.  The 
heights  at  these  times  are  as  follow  s : 


Elevation 
Sandy  Hook 

Elevation 
Throgs  Neck 

Difference 

Mean 
elevation 

Maximum  slope  north  

Maximum  slope  south  

+2.0 
—2.0 

—3.4 
+3.4 

5.4 
5.4 

—0.7 
+0.7 

At  the  time  of  greatest  slope  south,  therefore,  it  is  seen  that,  although  the  slope  is 
the  same,  elevations  throughout  the  East  river  are  more  than  one  foot  higher  than  on 
the  corresponding  north  slope.  The  southerly  slope,  therefore,  having  a  deeper 
channel  and  consequently  a  greater  hydraulic  radius,  must  generate  a  higher  velocity, 
and  as  this  velocity  acts  through  a  larger  cross-sectional  area,  the  rate  of  discharge 
must  be  correspondingly  increased. 

This  difference  of  stage  elevation,  between  slopes  produced  at  the  times  of 
northerly  and  southerly  flow,  holds  in  favor  of  the  latter  for  the  whole  period  of  the 
southbound  current,  consequently  the  entire  volume  passed  through  the  East  river 
during  this  period  must  be  in  excess  of  that  of  the  northerly  flow. 

During  1910-1911  the  Engineer  Department,  U.  S.  Army,  made  extensive  field  ob- 
servations in  the  vicinity  of  Hell  Gate,  under  the  direction  of  Col.  W.  M.  Black,  Corps 
of  Engineers,  U.  S.  Army,  with  a  view  to  relieving  the  currents  which  impede  navi- 
gation through  this  portion  of  the  East  river.  These  observations  include  very  com- 
plete gaugings  in  the  Harlem  and  East  rivers  and  auxiliary  channels,  and  an  investi- 
gation of  tidal  phenomena  in  this  vicinity.  Through  the  courtesy  of  Colonel  Black  the 
records  of  these  observations  are  placed  at  the  disposal  of  this  Commission,  and  form 
the  basis  of  the  present  investigation. 

The  flow  in  the  East  and  Harlem  rivers  and  the  subsidiary  channels  is  hydraulic ; 
i.  e.,  caused  by  the  head  or  difference  of  level  at  either  end.  However,  the  application 
of  the  laws  of  stream  flow  to  these  channels  is  complicated  by  the  constantly  changing 
heads  produced  by  the  progress  of  the  tidal  wave.  It  is  further  complicated  by  the 
varying  height  of  these  waves  caused  by  the  ever-changing  positions  of  the  sun  and 
moon  with  respect  to  the  earth,  by  the  interference  of  the  tidal  waves  entering  the 
East  river  by  way  of  Sandy  Hook  and  Throgs  Neck,  respectively,  and  by  the  varying 
levels  of  the  Atlantic  ocean  and  Long  Island  sound  under  wind  action. 

Owing  to  these  varying  factors,  discharge  measurements  taken  in  the  same 
channel  even  on  succeeding  tidal  cycles  may  differ  widely,  so  that  comparisons  be- 
tween gaugings  of  different  channels,  unless  made  simultaneously,  are  absolutely 
unreliable.  A  combination  of  circumstances  at  the  time  of  a  gauging  may  so  change 
conditions  as  to  cause  the  entire  disappearance  of  the  net  ebb  flow,  if  such  exists,  or 
to  reverse  its  direction. 

The  simultaneous  observations  of  current  velocities  at  the  required  number  of 
stations  would  have  necessitated  a  larger  party  and  equipment  than  was  available, 
and,  even  had  this  been  done,  the  results  would  have  represented  only  one  out  of  the 
many  combinations  of  tidal  conditions  which  may  exist  in  this  locality.  The  mean 
discharge  for  each  channel,  therefore,  was  adopted  as  the  basis  of  comparison. 

Since  the  velocities  and  consequently  the  discharges  result  from  the  slope  and 
stage,  it  may  be  assumed  that  similar  tidal  conditions  as  to  the  height  and  slope  will 


584         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


cause  equal  discharge  rates.  If,  then,  simultaneously  with  the  gauging  of  a  channel,  the 
tidal  heights  at  both  ends  be  continuously  observed,  the  resulting  records  will  show  the 
heads  or  slopes  produced  at  each  moment  of  the  observation,  as  well  as  the  discharge 
rates  generated  by  these  slopes. 

A  relation  may  now  be  found  between  slope  and  discharge,  which,  if  applied  to 
a  mean  tide  with  its  slopes,  will  give  the  mean  tidal  discharge  of  the  channel. 
Velocity  area  observations  are  expensive  and  require  great  care  if  accurate  results 
are  to  be  obtained.  Furthermore,  they  are  constantly  interrupted  by  traffic,  and  to 
continue  them  long  enough  to  obtain  a  true  mean  discharge  is  clearly  impracticable. 
On  the  other  hand,  observations  for  tidal  height  may  be  made  continuously,  accu- 
rately and  inexpensively  by  automatic  tide  gauges,  requiring  little  attention,  and 
entirely  independent  of  weather  conditions. 

The  period  of  observation  is  one  period  of  the  moon,  twenty-nine  days,  or  fifty- 
seven  consecutive  tidal  cycles,  and  is  known  as  a  "lunation." 

The  construction  of  a  mean  tidal  curve  from  the  record  of  an  automatic  gauge  is 
a  matter  of  considerable  labor,  but  comparative  simplicity.  The  record  is  in  the  form 
of  a  long  strip  of  paper  on  which  the  varying  heights  of  tide  are  represented  by  the 
distances  from  the  base  line  of  a  sinuous  curve  traced  by  the  recording  pencil.  Time 
is  measured  at  right  angles  to  the  height  ordinates,  or  along  the  base  line  mentioned 
above.  In  the  Stiehrle  Gauge,  which  was  used  in  these  investigations,  the  scale  is  one 
inch  equals  one  foot  of  height  and  one  hour  of  time.  At  intervals  of  a  day  or  two  are 
entries  upon  the  record  of  the  correct  time,  made  by  the  caretaker  of  the  gauge  in  his 
visits.  From  these  notes  the  time  is  corrected  for  the  entire  record,  and  the  times  of 
the  successive  lunar  transits  are  marked. 

The  exact  time  of  high  and  low  water  is  determined,  the  heights  measured  and 
tabulated  in  separate  columns.  The  intervals  between  high  and  low  water  are  then 
divided  into  six  equal  parts,  representing,  approximately,  lunar  hours,  and  the  height 
of  the  curve  is  determined  at  each  of  these  hours  and  tabulated,  as  explained  for  high 
and  low  water.  The  luni-tidal  intervals,  or  the  times  elapsing  between  the  moon's 
transit  and  high  and  low  water,  respectively,  are  also  determined  and  tabulated  in 
separate  columns.  The  mean  of  the  fifty-seven  items  in  each  column  determines  the 
elements  of  the  mean  tidal  curve;  i.  e.,  the  lunar  times  of  high  and  low  water,  and 
the  heights  of  the  curve  at  high  and  low  water  and  at  ten  intermediate  points. 

The  study  of  the  curve  thus  constructed  shows,  free  from  all  irregularities,  the 
characteristic  tidal  conditions  of  the  station.  A  storm  tide  during  the  period  of 
observation  has  no  appreciable  effect  upon  the  mean  curve  when  averaged  with  so 
many  other  tides.  The  range  of  such  a  curve  is  found  to  be  practically  constant,  as 
is  also  the  shape  of  the  curve,  but  the  stage  (=mean  sea  level)  or  elevation  midway 
between  high  and  low  water,  varies  greatly  at  different  seasons  of  the  year,  the  dis- 
crepancy sometimes  exceeding  half  a  foot.  The  mean  of  all  these  stages,  however,  for 
a  long  period,  is  the  plane  of  mean  sea  level,  as  established  by  the  Coast  Survey. 

Furthermore,  mean  curves  obtained  simultaneously  lie  at  the  same  stage,  although 
this  stage  may  vary  with  the  season.  For  purposes  of  comparison,  therefore,  it  is 
permissible  to  use  mean  curves  obtained  at  different  times,  provided  that  they  first  be 
adjusted  so  as  to  bring  their  mean  stage  to  the  plane  of  mean  sea  level. 

If  two  such  curves,  say  Lawrence  Point  and  Hallet's  Point,  be  plotted  upon  the 


CORRESPONDENCE— TIDAL  FLOW 


585 


same  time  ordinates,  the  difference  of  level  between  these  points  at  any  time  is  rep- 
resented by  the  vertical  distance  between  the  curves  at  that  time.  The  discharge  rate 
at  this  same  time  is  known  from  the  discharge  curve.  A  relation  between  the  two 
may  now  be  found. 

It  is  clear  that  this  relation  must  be  shown  in  a  manner  entirely  empirical.  Con- 
fusing factors  of  changing  head,  etc.,  enter  into  the  problem  so  as  to  make  any  mathe- 
matical determination  based  upon  the  laws  of  stream  flow  entirely  out  of  the  question. 

Moreover,  in  attempting  to  relate  discharge  to  slope,  it  must  be  remembered  that, 
in  the  case  of  immense  volumes  of  water  in  motion,  the  laws  of  inertia  and  mo- 
mentum must  exert  a  powerful  influence.  Changes  must  be  brought  about  gradually, 
and  existing  conditions  of  flow  may  often  be  due  to  slopes  which  have  changed  or 
ceased  to  be. 

Slack  water,  or  zero  current,  does  not  coincide  with  the  time  of  crossing  of  the 
curves,  or  zero  slope,  but  occurs  some  time  later.  In  other  words,  the  momentum  of 
the  moving  water  is  sufficient  to  keep  it  in  motion  not  only  through  the  zero  slope, 
but  until  a  marked  negative  slope  has  accumulated.  In  the  meantime,  the  water  has 
been  flowing  against  a  head,  or  uphill.  The  effective  head,  therefore,  becomes  zero  at 
slack  water,  and  for  a  period  before  and  after  slack,  the  effective,  rather  than  the 
actual  head,  must  be  considered. 

The  effective  head  is  greater  than  the  actual  before  slack,  owing  to  the 
momentum  of  the  water,  and,  by  reason  of  the  inertia  of  the  water  on  the  change  of 
tide,  it  lags  behind  the  actual  head  for  a  considerable  period  after  slack,  until  the 
velocity  has  picked  up. 

The  tidal  head,  corrected  for  momentum,  is  the  varying  factor  in  the  discharge 
formula  for  a  constant  channel  section,  and  may  be  used  in  a  graphical  diagram  in 
place  of  the  slope,  which  results  from  the  head.  The  channel  section,  however,  is  not 
constant,  varying  with  the  stage  of  the  tide,  which  is  thus  introduced  as  a  new  variable 
factor.  Of  a  number  of  parallel  slopes,  that  produced  at  the  highest  stages  will  gen- 
erate the  greatest  discharge  rate.  In  the  construction  of  a  graphical  diagram,  there- 
fore, both  slope  and  stage  must  be  taken  into  account. 

From  the  field  records,  the  discharge  rate  and  the  tidal  heights  at  both  ends  of 
the  channel  are  known.  The  difference  between  the  two  heights  is  the  head.  A  dia- 
gram may  now  be  constructed,  with  heads  as  ordinates  and  observed  discharge  rates 
as  abscissas.  At  the  intersection  of  the  coordinates  representing  observed  head  and 
simultaneous  discharge  rate,  is  written  the  actual  tidal  elevation  at  Lawrence  Point, 
which,  with  the  known  slope,  determines  the  stage  throughout  the  channel.  Simi- 
larly, points  are  plotted  for  each  quarter  hour,  say,  of  the  observation.  Curves  are 
then  drawn  through  the  points  representing  equal  elevation  at  Lawrence  Point,  one 
for  each  even  foot  of  the  stage.  Logarithmic  plotting  is  employed,  it  having  the  great 
advantage  for  work  of  this  character  that  the  "curves"  become  straight  lines  and  are 
parallel. 

To  reverse  the  process  and  obtain  from  the  diagram  the  discharge  rate  corre- 
sponding to  given  elevations  at  both  ends  of  the  channel,  the  procedure  is  as  follows : 
Find  upon  the  left-hand  margin  the  difference  of  height,  or  head;  follow  the  hori- 
zontal line  through  this  point  to  the  diagonal  representing  the  tidal  height  at  Law- 
rence Point;  vertically  above  this  intersection,  on  the  upper  margin,  will  be  found 


586 


DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


the  required  discharge  rate.  Separate  diagrams  are  constructed  for  both  the  flood 
(north)  and  the  ebb  (south)  flow. 

Four  sets  of  such  diagrams  were  constructed:  For  Hell  Gate  (Main  Channel), 
Little  Hell  Gate,  Harlem  Kills,  and  the  Harlem  river  (217th  street),  based  upon  con- 
tinuous current  observations  for  three  days  (6  tidal  cycles)  at  each  point,  excepting 
Hell  Gate,  where  two  cycles  of  13  hours  each  were  observed,  upon  a  spring  and  a 
neap  tide  respectively. 

Having  established  a  relation  between  slope,  stage  and  discharge,  it  is  now  pos- 
sible to  determine  the  mean  discharge  by  means  of  the  diagram,  making  use  of  the 
mean  tidal  curves  of  the  channel  in  question.  It  only  remains  to  assure  ourselves 
that  the  curves  actually  represent  mean  conditions.  Each  curve  is  the  mean  of  57 
consecutive  tidal  cycles,  or  one  period  of  the  moon,  in  all  its  phases.  Were  the  moon 
the  only  heavenly  body  to  be  considered,  this  period  should  yield  a  true  mean  curve. 
However,  the  sun,  and,  according  to  the  Coast  Survey,  34  other  heavenly  bodies,  are 
considered  in  the  compilation  of  their  tide  tables. 

Only  the  effect  of  the  sun,  however,  need  be  considered  here,  as  even  its  influence 
is  less  than  half  that  of  the  moon,  and  the  other  elements  do  not  enter  with  sufficient 
influence  to  merit  consideration.  The  effect  of  the  sun,  in  its  varying  distances  from 
the  earth,  seems  to  result  in  a  raising  or  lowering  of  the  whole  tidal  curve,  without 
altering  its  shape  or  range.  Thus,  if  in  any  particular  month  the  high  waters  are 
higher  than  in  another,  the  low  waters  are  correspondingly  higher,  and  the  stage  is 
raised.  A  mean  of  the  mid-stages  for  a  solar  period  (one  year)  is  the  plane  of  mean 
sea  level.  Since  the  shape  and  range  of  one  lunation  (57  cycles)  do  not  materially 
differ  from  those  of  any  other,  it  may  be  considered  that  any  good  mean  curve  of  a 
station  for  one  lunation,  with  its  mean  height  adjusted  to  the  plane  of  mean  sea  level, 
represents  mean  conditions  at  that  station  sufficiently  well  for  the  purpose. 

Again,  for  curves  obtained  simultaneously,  the  mean  height  is  always  the  same, 
and  any  conditions  which  affect  one,  influence  the  other  to  the  same  extent.  Wherever 
possible,  the  comparative  curves  used  in  this  investigation  are  of  simultaneous  observa- 
tion, particularly  for  the  main  channel  of  Hell  Gate,  which  carries  the  greatest  flow, 
and  is  the  predominant  factor  in  the  problem. 

From  the  mean  tidal  curves  of  Lawrence  Point  and  Hallet's  Point,  therefore,  the 
heights  at  intervals  of  half  an  hour  are  measured,  and  from  these  the  corresponding 
discharge  rates  are  obtained  from  the  discharge  diagram.  These  rates  are  erected  as 
ordinates  to  the  "discharge  curve,"  whose  abscissas  are  time  and  whose  ordi- 
nates  are  rates  of  discharge.  These  ordinates  are  positive,  or  measured  up  from  the 
horizontal  axis,  during  the  flood  flow,  and  negative,  or  measured  down,  during  the 
ebb  flow.   The  curve  passes  through  zero  at  slack  water. 

The  area  lying  between  the  curve  and  its  horizontal  axis,  being  the  product  of 
time  by  rate  of  discharge,  represents  the  total  volume  discharged  in  one  tide.  Inte- 
grating this  curve  for  Hell  Gate,  the  volume  discharged  on  a  mean  tide  is  found  to  be 
as  follows: 


HELL  GATE  DISCHARGE 


Ebb  (South)  volume. . 
Flood  (North)  volume 


4,482,665,000  cu.  ft. 
4,221,170,000  " 


Ebb  excess 


261,495,000  cu.  ft. 


CORRESPONDENCE— TIDAL  FLOW 


587 


From  the  observed  data  in  Little  Hell  Gate,  Harlem  Kills  and  the  Harlem  river, 
mean  tidal  curves,  discharge  diagrams,  and  discharge  curves  were  constructed  for 
these  channels. 

From  the  discharge  curves  were  determined  the  total  flood  and  ebb  volumes  in 
each  of  these  channels  fox  one  tidal  cycle.    The  ebb  flow  in  all  cases  is  the  greater. 

LITTLE  HELL  GATE 

Ebb  (West)   326,588,700  cu.  ft. 

Flood  (East)   183,747,900  " 

Ebb  excess   142,840,800  cu.  fc. 

HARLEM  KILLS 

Ebb  (West)   113,059,170  cu.  ft. 

Flood  (East)   57,520,546  " 

Ebb  excess   55,538,624  cu.  ft. 

HARLEM  RIVER,  217TH  STREET 

Ebb  (North)   252,366,000  cu.  ft. 

Flood  (South)   207,912,000  " 

Ebb  excess   44,454,000  cu.  ft. 

In  view  of  the  generally  accepted  figures  these  values  appear  to  be  too  large,  but 
they  must  be  regarded  as  the  result  of  careful  field  work  with  observations  extending 
over  a  period  of  two  years,  while  other  determinations  are  based  upon  theory  alone. 

When  one  considers  that  in  the  Hell  Gate  channel  alone  the  mean  head  for  the 
duration  of  the  ebb  is  1.8S  that  of  the  flood,  and  that  the  sectional  area  at  the  strength 
of  the  ebb  is  8  per  cent,  greater  than  the  corresponding  flood  area,  then  the  ebb  excess 
of  6.2  per  cent,  of  the  flood  volume  does  not  seem  unreasonable.  Nor,  in  view  of  the 
excess  of  ebb  area  over  flood  at  strength  in  Little  Hell  Gate  and  Harlem  Kills,  of 
57  per  cent,  and  105  per  cent,  respectively,  does  an  excess  of  ebb  flow  nearly  equal  to 
the  total  flood  volume  appear  absurd.  The  following  table  shows  for  each  of  these 
channels  the  increase  of  sectional  area  and  of  head  both  at  the  strength  of  the  ebb 
and  flood,  and  of  a  mean  for  the  duration  of  flow.  The  ebb  excess,  as  a  percentage  of 
the  flood  volume,  is  also  tabulated. 


TABLE  CX 


Ratios 


Hell  Gate 


Little 
HeU  Gate 


Harlem 
Kills 


Harlem 
river 


Ebb  head  to  flood  head  at  strength  

Ebb  head  to  flood  head,  mean  for  duration  of  flow 

Ebb  area  to  flood  area  at  strength  

Ebb  area  to  flood  area,  mean  for  duration  of  flow. 

Net  ebb  excess  to  total  flood  volume  

Duration,  ebb  to  flood  


1.5 
1.88 
1.08 
1.03 

.062 
1.00 


0.64 
0.68 
1.57 
1.16 


1 


.  19 

22 


0.68 
0.74 
2.05 
1.26 

.966 
1.14 


1.0 
1.08 
1.08 
1.07 
.21 
1.04 


Of  the  flood  volume  in  the  East  river,  towards  Long  Island  sound,  a  small  portion 
enters  from  the  Hudson  river  by  way  of  Harlem  river.  This  flow  reaches  the  East 
river  through  Harlem  Kills  and  Little  Hell  Gate,  although  the  latter  channel  carries 
a  small  portion  of  the  flow  which  comes  up  from  the  Lower  East  river.  By  far  the 
greater  part  of  this  discharge,  however,  is  through  the  main  Hell  Gate  channel,  be- 
tween Astoria,  L.  I.,  and  Ward's  Island.  On  the  ebb,  Harlem  Kills  carries  nearly  half 


588 


DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


the  flow  of  the  Harlem  river,  and  Little  Hell  Gate  carries  an  increased  percentage  of 
the  flow  of  the  Lower  East  river. 

The  discharge  of  the  Upper  East  river,  north  past  Lawrence  Point,  is  equal  to 
the  combined  volumes  from  Hell  Gate,  Little  Hell  Gate  and  Harlem  Kills.  The  dis- 
charge south  is,  in  a  like  manner,  equal  to  the  combined  ebb  flow  of  these  three 
channels.  Past  88th  street,  north,  the  flow  of  the  Lower  East  river  is  equal  to  that 
as  found  for  the  Upper  East  river,  less  that  which  enters  from  the  Harlem  river,  which 
does  not  pass  88th  street.  The  flow  south  past  88th  street  is  equal  to  that  south  past 
Lawrence  Point,  less  that  which  escapes  through  the  Harlem,  and  which,  therefore, 
does  not  pass  88th  street. 

But  at  the  commencement  of  the  south  flow,  the  water  surface  in  the  basin  be- 
tween Lawrence  Point  and  88th  street  is  nearly  five  feet  higher  than  at  its  com- 
pletion. The  water  occupying  this  space,  or  the  tidal  prism,  which  was  in  place  at 
the  commencement  of  flow,  and,  therefore,  did  not  enter  past  Lawrence  Point,  must 
have  run  out  past  88th  street,  increasing  this  flow  by  the  volume  of  the  prism.  How- 
ever, on  the  reverse  current,  this  same  amount  will  enter  past  88th  street  and  raise 
the  water  to  its  original  height,  but  ivill  not  flow  out  past  Lawrence  Point.  Hence 
the  effect  of  this  tidal  prism  will  be  to  increase  both  the  flood  and  ebb  discharges 
past  88th  street  by  an  equal  amount,  leaving  the  net  excess  unchanged. 

The  ebb  excess  for  the  Upper  East  river,  therefore,  is  the  combined  excesses  of 
Hell  Gate,  Little  Hell  Gate,  and  Harlem  Kills,  and  for  the  Lower  East  river  it  is  the 
same  amount,  diminished  by  the  ebb  excess  of  the  Harlem  river. 

The  volumes  of  flow  as  determined  for  Hell  Gate  and  the  auxiliary  channels, 
when  combined  in  the  manner  indicated  above,  give  the  following  results: 

Flood  Ebb 
(Towards  L.  I.  Sound)  (Towards  N.  Y.  Bay) 

Hell  Gate  (Main  Channel)  4,221,170,000  cu.  ft.  4,482,665,000  cu.  ft. 

Little  Hell  Gate   183,747,900    "  326,588,700  " 

Harlem  Kills   57,520,546    "  113,059,170  " 

Sum   4,462,438,446  cu.  ft.  4,922,312,870  cu.  ft. 

Total  flood  volume   4,462,438,446  " 

Net  ebb  excess,  Upper  East  river   459,874,424  cu.  ft. 

Net  ebb  excess,  Harlem  river   44,454,000  " 

Net  ebb  excess,  Lower  East  river   415,420,424  cu.  ft. 


Professor  Mitchell  in  1886  obtained  the  following  values: 


Net  ebb  excess,  Upper  East  river   432,000,000  cu.  ft. 

Net  ebb  excess,  Lower  East  river   418,000,000  " 

Difference  (=Ebb  excess,  Harlem  river)   14,000,000  cu.  ft. 


The  net  ebb  excess  of  the  Lower  East  river  represents  the  amount  of  water  dis- 
charged into  New  York  bay  by  the  East  river  in  one  tidal  cycle,  over  that  withdrawn 
in  the  same  cycle,  while  the  excess  of  the  Upper  East  river  represents  the  net  gain 
to  the  whole  harbor  of  clean  sea  water  drawn  from  the  sound. 

Respectfully  submitted, 
E.  F.  Robinson, 

Assistant  Engineer. 


CORRESPONDENCE— TIDAL  FLOW 


589 


Under  date  of  October  9,  1913,  the  reply  of  the  Survey  is  given  to  the  Commis- 
sion's request  for  an  opinion  as  to  the  accuracy  of  the  re-estimation  of  the  flow  of 
water  through  the  East  river,  based  on  Colonel  Black's  data.  This  reply  is  here  given 
as  Exhibit  IX. 

EXHIBIT  IX 

October  9,  1913. 

Dr.  George  A.  Soper, 

President,  Metropolitan  Sewerage  Commission, 
17  Battery  Place,  New  York  City. 

Sir  :  In  compliance  with  your  request  originally  made  on  May  13,  1913,  that  an 
examination  be  made  of  a  report  by  E.  F.  Robinson,  Assistant  Engineer,  concerning 
the  gauging  of  the  tidal  streams  in  the  East  and  Harlem  rivers,  I  submit  the  follow- 
ing remarks  and  criticisms. 

Replying  first  to  the  statement  made  upon  pp.  1,  2  of  this  report,  viz.,  "It  is  sig- 
nificant, however,  that  of  all  these  later  estimates,  not  one  is  based  upon  actual  field 
observations,"  it  will  probably  suffice  to  refer  to  a  letter  from  this  office  to  Dr.  Soper, 
dated  Feb.  6,  1909,  particularly,  pp.  7-11. 

In  this  same  letter  a  computation  is  made  based  upon  the  known  depths  and  tides 
which  shows  (p.  4)  that  in  the  Hell  Gate  (near  Frying  Pan)  the  ratio  of  the  ebb- 
stream  section  to  the  flood-stream  section  is  about  1.077.  But  (see  p.  10)  it  is  not 
reasonable  to  suppose  that  this  value  represents  the  ratio  of  the  ebb  to  the  flood 
volume  because  such  ratio  must  depend  upon  all  sections  of  the  East  river  between 
Governor's  Island  and  Lawrence  Point.*  In  fact  the  few  observations  which  have 
been  made  in  this  immediate  locality  indicate  that  the  east-going  stream  is  the 
stronger.  The  plottings  sent  with  the  letter  of  February  6,  1909,  show  clearly  that 
off  Old  Ferry  Point  the  velocity  of  the  east-going  stream  exceeds  that  of  the  west- 
going.  As  a  consequence  the  ratio  must  probably  be  reduced  to  a  ratio  nearer  unity. 
Around  Blackwell's  Island  the  ratio  of  the  ebb-stream  section  to  the  flood-stream 
section  is  very  nearly  unity.  The  observed  velocities  at  six  stations  around  this  island 
indicate  that  the  required  ratio  for  the  tidal  volumes  is  1.03,  which  appears  to  be  a 
reasonable  value  (p.  10).  The  ratio  which  Mr.  Robinson's  figures  give  for  a  section 
somewhat  further  to  the  eastward  is  448. .  .-=-422. ..  =1.06.  Mitchell's  values  for  a 
section  off  19th  street,  probably  based  chiefly  upon  the  observations  taken  in  1885 
(Coast  Survey  Report,  p.  36,  for  1886),  give  445. .  .-^-401. .  .=1.11  as  this  ratio.  The 
values  of  the  excess  of  ebb  over  flood  derived  from  observations  taken  off  19th  street 
and  off  Old  Ferry  Point  in  1885,  and  given  upon  p.  426,  Coast  Survey  Report  for 
1886,  indicate  that  the  ratio  of  the  ebb  volume  to  flood  volume  is  somewhat  less  than 
1.11.  The  observations  taken  in  1886  (Oct.  4-7)  were,  of  course,  not  included  in 
Mitchell's  estimate  dated  June  25,  1886.  The  brevity  of  the  1885  and  1886  observa- 
tions taken  in  connection  with  the  irregularities  of  the  current  as  shown  upon  p.  423, 
Report  for  1886,  and  opposite  p.  305,  Report  for  1887,  preclude  the  accurate  deter- 
mination, from  them  alone,  of  the  resultant  flow,  which  is  a  comparatively  small 
quantity.! 

*See  also  formula  3,  p.  567,  letter  from  this  office  to  Dr.  Soper,  dated  Aug.  14, 1908;  also  letter  to  Kenneth  Allen, 
dated  Sept.  30,  1908. 

tSee  pp.  575,  576,  letter  to  Dr.  Soper,  Feb.  6,  1909. 


590        DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


Returning  now  to  Mr.  Robinson's  report,  it  will  be  noted  (p.  10)  that  for  his 
Main-Channel  section  (near  Negro  Point  Bluff)  the  current  observations  comprised 
two  periods  of  13  hours  each.  As  the  observations  do  not  accompany  Mr.  Robinson's 
report,  nor  are  they  given  in  the  more  extended  paper  by  Colonel  Black  ( Professional 
Memoirs,  Corps  of  Engineers,  U.  S.  A.,  May- June,  1913),  it  is  impossible  to  judge  con- 
cerning the  accuracy  of  the  determination  and  especially  in  reference  to  the  ebb  excess, 
which  is  a  comparatively  small  quantity. 

The  computations  and  estimates  which  have  been  furnished  by  this  office  were 
made  without  especial  reference  to  Little  Hell  Gate,  Harlem  Kills  and  Harlem  river, 
as  we  possess  very  few-  observations  made  in  these  straits. 

On  account  of  the  shallowness  of  Little  Hell  Gate  and  of  Harlem  Kills,  there 
can  be  no  doubt  but  that  the  ebb  excess  through  these  two  passages  is  considerable. 

From  pp.  13,  14  of  Mr.  Robinson's  report  the  following  values  of  ebb  and  flood 
volumes  are  taken : 

LITTLE  HELL  GATE 

Ebb  (West)   326,588,700  cu.  ft. 

Flood  (East)   183,747,900 

Ebb  excess   142,840,800  cu.  ft. 

HARLEM  KILLS 

Ebb  (West)   113,059,170  cu.  ft. 

Flood  (East)   57,520,546 

Ebb  excess   55,538,624  cu.  ft. 

HARLEM  RIVER— 217TH  STREET 

Ebb  (North)   252,366,000  cu.  ft. 

Flood  (South)   207,912,000  " 

Ebb  excess   44,454,000  cu.  ft. 

If  the  Little  Hell  Gate  and  the  Harlem  Kills  values  be  added  together  we  have 

LITTLE  HELL  GATE  AND  HARLEM  KILLS 

Ebb  (West)   439,647,870  cu.  ft. 

Flood  (East)   241,268,446  " 

Ebb  excess   198,379,424  cu.  ft. 

If  these  determinations  are  correct,  it  is  a  little  surprising  that  of  the  198,379,424 
cu.  ft.  excess  from  Little  Hell  Gate  and  Harlem  Kills  only  44,454,000  cu.  ft.,  or  less 
than  one-fourth  part,  pass  through  the  Harlem  river  to  the  Hudson,  whereas  consid- 
erably more  than  half  of  the  ebb  or  flood  volume  passing  these  two  straits  passes 
through  the  Harlem  river. 

The  ebb  or  north-going  volume  of  the  Harlem  river  is  undoubtedly  greater  than 
the  flood  or  south-going  volume  because  during  the  north-going  stream  the  average 
depth  of  the  river  throughout  practically  its  entire  length  is  greater  than  during  the 
south-going. 

The  ebb  stream  from  Little  Hell  Gate  entering  the  basin-like  expanse  around 
Great  Mill  Rock  must  lessen  the  fall  or  hydraulic  head  through  the  main  channel, 
thus  tending  to  decrease  the  ebb  velocity  occurring  between  Astoria  and  Ward's 
Island,  and  at  points  further  eastward.    The  flood  velocity  in  the  Hell  Gate  is  like- 


CORRESPONDENCE— TIDAL  FLOW 


591 


wise  diminished  by  the  existence  of  Little  Hell  Gate,  but  not  to  the  same  extent. 
This  is  probably  one  of  the  reasons  why  the  velocity  of  the  east-going  stream  in  the 
main  channel  exceeds  that  of  the  west-going,  a  fact  which  most  observations  indicate. 

The  chief  reason  for  believing  that  the  flood  and  ebb  volumes  are  nearly  equal 
for  any  given  section  of  the  East  river  from,  say,  Brooklyn  Bridge  to  Lawrence  Point 
(Little  Hell  Gate  included)  is  that  whereas  the  water  is  generally  deeper  on  the  ebb 
stream  than  on  the  flood  for  sections  eastward  and  northward  from  BlackwelPs  Island 
the  reverse  is  true  for  sections  to  the  south  westward.  This  has  been  already  explained 
in  the  letter  dated  Feb.  6,  1909,  pp.  6,  et  seq. 

In  order  to  see  that  the  flow  depends  upon  a  channel  throughout  its  entire  length, 
and  not  upon  a  particular  constricted  portion  where  the  velocity  is  greatest,  it  is  only 
necessary  to  note  that  if  an  obstruction  like  a  dike  or  jetty  were  built  out  from  either 
bank  of  a  uniform  channel  of  considerable  length  there  reducing  the  cross-section  to 
one-half  of  its  value  elsewhere  along  the  channel,  the  amount  of  flow  due  to  a  given 
head  and  for  a  given  period  would  not  be  seriously  affected  by  such  obstruction 
although  the  velocity  for  the  particular  cross-section  would  be  doubled. 

In  the  case  of  the  East  river,  and  notably  its  eastern  portion,  the  area  of  any 
particular  cross-section  varies  as  the  tide  there  rises  and  falls.  But  it  does  not  follow 
that  the  ratio  between  the  ebb  and  flood  volumes  for  this  river  will  be  that  of  the  ebb 
and  flood  cross-sectional  areas  at  the  particular  section  taken;  e.  g.,  in  the  Hell  Gate 
proper.  The  resistances  of  all  portions  of  the  river  bed  enter  into  the  question  of 
tidal  volumes.  (See  letter  dated  Aug.  14,  1908,  formula  (3),  p.  24;*  and  letter  dated 
Feb.  6,  1909,  pp.  10,  11.) 

In  regard  to  the  methods  used  by  the  Engineers  in  correlating  the  current  obser- 
vations with  the  tidal  records,  and  described  in  Colonel  Black's  paper  and  also  in  Mr. 
Robinson's  report,  a  few  statements  may  be  submitted : 

If  the  relation  between  "difference  of  head"  and  "discharge"  at  a  given  section 
are  to  be  represented  by  means  of  equidistant  parallel  straight  lines  drawn  upon  log- 
arithmic cross-section  paper,  the  implied  assumptions  are:  That  the  velocity  at  any 
particular  time  is  proportional  to  some  power  (say  the  power  V2)  of  the  difference  of 
head,  and  that  the  effective  sectional  area  is  the  mean-half-tide-level  section  multi- 
plied by  a  factor  whose  logarithm  is  proportional  to  z,  z  denoting  the  ratio  of  the  height 
of  the  tide  reckoned  from  half-tide  level  to  the  depth  at  the  time  of  half-tide  level. 
This  is  nearly  equivalent  to  saying  that  the  factor  should  be  proportional  to  1+2 
since 

log  (1+2)  =M  (z-!+|3_...) 
=Mz 

when  z  is  small  in  comparison  with  unity.  That  the  factor  should  be  of  the  form 
1+2  is  a  natural  assumption  and  one  which  must  be  fairly  good,  especially  when  the 
banks  of  the  stream  between  low  and  high-water  marks  are  nearly  vertical,  the  range 
of  tide  small  in  comparison  with  the  depth,  and  the  entire  length  of  the  strait  connect- 
ing the  two  tidal  bodies  not  long  enough  for  the  bed  resistance  to  become  too  pro- 
nounced. For  long  straits,  like  the  East  river,  the  velocity  depends  upon  the  cross- 
section  as  well  as  upon  the  head,  as  formula  3,  letter  dated  Aug.  14,  1908,  shows.  In 
the  case  of  a  long  and  nearly  uniform  canal  the  tendency  is  to  approach  a  value  of 
which  one  factor  is  the  square  root  of  the  hydraulic  mean  depth  ( formulas  of  Prony, 
*Page  567,  this  report. 


592        DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


Etelwein,  Tadini  and  others*),  and  so  the  discharge,  corresponding  to  a  given  slope, 
must  contain  not  only  the  factor  l-\-z  but  y/l-\-z'  where  z'  is  a  fraction  denoting  the 
amount  of  hydraulic  mean  depth  increase  due  to  the  stage  of  the  tide,  the  latter  being 
measured  from  half-tide  level. 

That  the  relative  velocities  at  a  given  section  are  proportional  to  the  square  root 
of  the  difference  between  two  near-by  heights,  as  is  implied  in  the  straight-line  plottings 
on  logarithmic  cross-section  paper,  is  probably  nearly  true,  because  the  scheme  of  ob- 
serving does  not  contemplate  the  comparison  of  the  velocities  of  one  section  with 
those  of  another.  It  is  to  be  borne  in  mind,  however,  that  the  actual  flow  across  any 
given  section,  or  in  any  given  reach,  of  East  river  is  dependent  upon  all  portions  of 
the  river  from  one  end  to  the  other.  If  the  expansions  and  contractions  of  the 
channel  are  so  gradual  that  no  considerable  energy  is  for  that  reason  lost,  the  case  is 
quite  different  from  the  case  of  a  compound  reservoir  whose  component  parts  are  con- 
nected by  means  of  small  straits,  and  where  most  of  the  energy  is  lost.  In  this  con- 
nection references  may  be  made  to  pp.  253,  254  and  263,  Coast  and  Geodetic  Survey 
Report  for  1907. 

It  seems  to  be  tolerably  certain  that  more  current  observations  should  be  made  at 
the  gauging  section  near  Negro  Point  Bluff  before  the  resultant  discharge  of  East 
river  can  be  determined  with  any  considerable  accuracy,  and  in  accordance  with  the 
scheme  outlined  in  Mr.  Robinson's  report. 

So  far  as  this  question  alone  is  concerned,  matters  would  doubtless  be  simplified 
by  selecting  one  or  more  gauging  sections  between,  say,  Hallett's  Cove  and  the  Brook- 
lyn Bridge. 

In  order  to  settle  this  question  in  as  satisfactory  a  manner  as  possible,  measure- 
ments should  be  made  at  times  when  there  is  comparatively  little  fresh  water  coming 
down  the  Hudson,  and  also  at  times  when  the  amount  is  considerable.  This  would 
enable  one  to  ascertain  whether  or  not  the  fresh  water  coming  through  the  Harlem 
has  any  sensible  bearing  upon  the  question  of  net  discharge  in  lower  East  river. 

Respectfully, 

F.  W.  Perkins, 

Acting  Superintendent. 

The  Survey's  answer  states  as  tolerably  certain  that  more  current  observations 
should  be  made  before  the  resultant  discharge  of  the  East  river  can  be  determined  with 
any  considerable  accuracy  in  accordance  with  the  scheme  submitted  to  the  Survey  for 
consideration.  In  the  Survey's  opinion,  in  order  to  reply  to  this  question  satisfac- 
torily, measurements  should  be  made  at  other  times  than  those  included  in  Colonel 
Black's  series,  especially  at  times  when  there  is  comparatively  little  fresh  water 
coming  down  the  Hudson  and  times  when  the  amount  is  considerable,  the  application 
to  this  point  being  to  ascertain  whether  or  not  the  fresh  water  coming  through  the 
Harlem  has  any  sensible  bearing  upon  the  question  of  net  discharge  in  the  Lower  East 
river. 

♦See  Bovey's  Hydraulics,  2d  ed,  pp.  144-155  and  Ch.  III. 


CORRESPONDENCE— TIDAL  FLOW  593 
CONCLUSION 

The  studies  indicated  in  the  foregoing  correspondence  show  only  a  part  of  the 
investigations  which  have  been  made  by  the  Commission  into  the  tidal  phenomena  of 
New  York  harbor.  Other  work  has  consisted  of  various  extensive  series  of  long- 
continued  float  observations  as  described  in  part  in  the  report  of  the  Commission 
dated  April  30,  1910,  and  more  fully  set  forth  in  Chapter  IV,  Part  IV  of  this  report. 

For  a  year  observations  were  made  of  the  salinity  of  the  water  at  11  stations 
located  in  the  more  important  parts  of  the  harbor,  the  object  of  this  work  being  to 
determine  needed  information  on  the  circulation  of  the  ocean  and  river  waters.  A 
brief  description  of  the  salinometer  work  will  be  found  in  the  Commission's  report  of 
April  30,  1910.    The  original  data  were  too  voluminous  to  print. 

The  net  result  of  all  the  tidal  studies  is  in  harmony  with  the  opinions  derived 
from  the  exhaustive  analytical  investigations  of  the  water  which  the  Commission  has 
carried  on.  Every  essential  fact  that  has  been  capable  of  withstanding  serious  criti- 
cism indicates  that  the  net  or  resultant  flow  seaward  of  water  from  the  most  congested 
parts  of  the  harbor  is  small  and  not  to  be  depended  upon  as  a  means  of  carrying  the 
sewage  of  New  York  promptly  to  the  open  sea.  The  water  oscillates  under  the  tidal 
influences  in  such  manner  as  to  cause  the  sewage  substances  which  are  discharged 
into  the  Harlem,  Lower  East  river  and  some  other  parts  of  the  harbor  to  remain  for 
long  and  indefinite  periods.  The  disposal  of  the  sewage,  in  so  far  as  it  disappears,  is 
ascribable  chiefly  to  natural  assimilative  processes  which  the  Commission  has  described 
in  its  reports  under  the  general  title  of  Digestion. 


594        DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


SECTION  III 

CORRESPONDENCE  RELATING  TO  PROBABLE  STABILITY  OF  AN 

ARTIFICIAL  ISLAND 

When,  during  the  course  of  the  Commiission's  (investigations,  the  opinion  was 
reached  that  it  would  be  desirable  to  carry  a  large  quantity  of  sewage,  estimated  at 
about  200  million  gallons  per  day,  from  the  territory  naturally  tributary  to  the 
Lower  East  river  out  of  that  part  of  the  harbor  and  discharge  it  at  sea,  the  question 
of  a  suitable  site  for  the  outlet  became  of  much  interest.  There  were  comparatively 
few  points  in  the  ocean  close  to  it  where  the  necessary  island  for  the  outfall  works 
could  be  constructed.  After  considerable  study,  the  Commission  decided  tentatively 
upon  two  alternate  sites  and  submitted  these  positions  to  the  Survey,  with  a  request 
for  an  opinion  as  to  the  probable  effect  which  the  waves  and  currents  in  the  vicinity 
might  be  expected  to  have  upon  the  structure.  The  Commission's  letter  to  the  Survey, 
dated  November  27,  1912,  describes  the  island  proposed  and  the  two  alternative  sites. 
The  letter,  which  is  marked  Exhibit  X,  here  follows: 

EXHIBIT  X 

New  York,  November  27,  1912. 

O.  H.  Tittmann,  Esq.,  Director, 

U.  S.  Coast  &  Geodetic  Survey, 
Washington,  D.  C. 

Dear  Sir  :  We  beg  to  ask  you  for  information  concerning  the  permanency  of  the 
natural  configuration  of  Lower  New  York  bay.  This  inquiry  arises  from  projects 
being  considered  by  this  Commission  for  the  location  of  a  sewer  outfall  of  large  size 
on  a  sand  reef  near  the  14-foot  channel. 

We  would  like  to  know  whether  an  island,  say  50  acres  in  extent,  would  be  per- 
manent, if  constructed  of  sand  enclosed  within  a  rip-rap  wall  about  250  feet  at  bot- 
tom and  60  feet  at  top,  the  whole  to  be  raised  to  a  height  of  about  18  feet  above  low 
tide.  The  location  would  be  north  of  the  14-foot  channel,  a  little  east  of  a  line  be- 
tween the  Sandy  Hook  beacon  and  Coney  Island  light. 

We  have  supposed  this  location  would  be  favorable  to  stability  in  spite  of  the 
heavy  waves  which  might  be  expected  from  the  ocean  in  some  severe  storms.  The 
reef  which  is  south  and  east  of  the  point  indicated  should,  we  suppose,  protect  the 
structure  to  a  considerable  extent. 

Questions  which  we  think  should  be  considered  in  this  connection  are  the  velocity 
of  currents  and  the  movement  of  sand  along  the  bottom  under  present  conditions  and 
under  conditions  which  would  occur  after  the  island  was  constructed.  The  sewage 
would  be  discharged  after  treatment  for  the  removal  of  impurities  and  should  not  be 
expected  to  produce  deposits  or  materially  alter  the  force  and  direction  of  the  cur- 
rents of  tidal  water  in  the  vicinity,  although  the  volume  of  sewage  would  be  large. 

Very  sincerely, 

George  A.  Soper, 

President. 


CORRESPONDENCE— STABILITY  OF  OUTLET  ISLAND  595 

Under  date  of  March  31,  1913,  the  Survey  transmitted  certain  material  which  re- 
lates to  the  inquiries  contained  in  Exhibit  X.  Exhibit  XI  contains  the  Survey's 
reply.  It  deals  with  the  subject  of  currents,  flow  of  water  and  winds  in  the  Lower  bay 
and  with  wave  action,  the  movement  of  suspended  matter,  principles  of  breakwater  de- 
sign and  with  the  probable  permanency  of  the  proposed  structure.  A  large  amount  of 
material  in  tabular  form  relating  chiefly  to  winds  at  the  site  of  the  island  over  a  period 
of  many  years  has  been  omitted  from  the  exhibit  because  of  the  space  required  and  as 
not  indispensable  to  an  understanding  of  the  essential  matters  involved. 

EXHIBIT  XI 

March  31,  1913. 

Matters  Relating  to  the  Permanency  of  the  Natural  Configuration  of  Lower  New 
York  Bay  and  the  Stability  of  an  Artificial  Island. 

Currents  at  Entrance  to  Lower  New  York  Bay 

The  tidal  currents  over  considerable  portions  of  Sandy  Hook  bay,  Raritan  bay, 
Lower  New  York  bay  and  Jamaica  bay  turn  from  flood  to  ebb  or  ebb  to  flood  nearly 
simultaneously.  Locations  of  comparatively  early  currents  are,  East  coast  of  Sandy 
Hook,  West  coast  of  Sandy  Hook,  and  Gravesend  bay.  The  localities  southwest,  west 
and  northwest  from  Coney  Island  light  have  comparatively  late  currents.  Between 
Elm  Tree  beacon  and  Great  Kills  the  currents  are  weak  and  do  not  turn  simul- 
taneously. 

Between  Sandy  Hook  and  Coney  Island  the  ordinary  maximum  velocity  seldom 
reaches  two  knots  per  hour.  These  currents,  although  not  strong,  have  an  important 
influence  upon  the  channels  and  shoals. 

For  a  map  showing  the  times  of  maximum  flood  velocity  in  Lower  New  York  bay 
and  vicinity,  see  Fig.  12,  opposite  p.  256,  Coast  and  Geodetic  Survey  Report  for  1907. 

The  accompanying  table  shows  the  results  of  current  observations  made  in  the 
vicinity  of  Fourteen  Foot  Channel  and  the  accompanying  blue  print*  shows  their 
location. 

Proofs  that  between  Coney  Island  and  Sandy  Hook  the  sand  is  moved  by  currents : 

1.  The  directions  of  the  shoals  and  of  the  natural  channels  agree  better  with  the 
directions  of  the  current  than  with  the  direction  of  the  prevailing  wind. 

2.  The  currents  here  are  sufficiently  strong  for  driving  sand  along  the  bottom; 
that  is,  they  exceed  0.4  knot  at  the  times  of  ordinary  maxima. 

3.  The  shoals  and  channels  are  here  better  differentiated  than  further  eastward. 
The  unusual  depth  in  Rockaway  Inlet  is  maintained  by  the  action  of  the  tidal 

current.  The  shoal  to  the  west  of  this  inlet  is  caused  by  the  fact  that  the  flood  stream 
north  of  the  western  end  of  Rockaway  Beach  flows  easterly,  while  the  flood  stream 
south  of  Coney  Island  flows  westerly,  the  times  of  maximum  velocity  being  nearly  the 
same  in  the  two  localities.  This  necessitates  a  very  small  velocity  between  Rockaway 
Inlet  and  the  eastern  end  of  Coney  Island. 


•Not  reproduced. 


DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


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CORRESPONDENCE— STABILITY  OP  OUTLET  ISLAND  597 


Rate  op  Influx  into  Lower  Bay,  New  York 

The  area  here  considered  extends  from  a  line  joining  the  north  angle  of  the  fort 
upon  Sandy  Hook  (about  830  feet  east  of  Hook  beacon)  and  "Continental  Tower,"* 
Coney  Island,  westward  to  sections  at  the  Narrows,  Tottenville,  Sayreville  and  Shrews- 
bury river  entrance. 

Sandy  Hook  Section 

The  rate  of  influx  across  the  Sandy  Hook  section  was  found  by  considering  16  par- 
tial sections,  each  2325.2  feet  in  length,  whose  average  depths  were  known  and  for 
which  the  current  velocities  were  estimated  from  observations  taken  in  the  localities 
of  each  partial  section. 

For  a  very  broad  section  like  that  extending  from  Sandy  Hook  to  Coney  Island, 
mean  velocities  may  be  derived  from  surface  velocities  (or  from  velocities  measured 
by  floats  extending  well  down  into  the  water)  by  multiplying  by  the  factor  0.9. f 
Moreover,  since  on  an  average  the  streams  do  not  cross  the  section  exactly  normally 
but  13°  from  a  normal  a  further  factor  of  cos  13°  or  0.97437  has  to  be  applied. 

The  half-tide  level  depths  and  the  velocities  as  ascertained  from  near-by  observa- 
tions are  as  follows,  beginning  at  the  Coney  Island  end : 


Depth, 

Velocity, 

No. 

feet 

knots 

Product 

1 

11 

0.8 

8.8 

2 

23 

1.6 

36.8 

3 

15 

1.3 

19.5 

4 

12 

1.2 

14.4 

5 

17 

1.2 

20.4 

6 

18 

1.4 

25.2 

7 

24 

1.5 

36.0 

8 

17 

1.7 

28.9 

9 

32 

1.9 

60.8 

10 

20 

1.3 

26.0 

11 

15 

1.3 

19.5 

12 

26 

1.4 

36.4 

pa 

13 

24 

1.3 

31.2 

14 

27 

1.2 

32.4 

15 

47 

1.6 

75.2 

16 

12 

1.5 

18.0 

489.5 


This  sum  multiplied  by  1.689  (the  factor  to  convert  velocities  expressed  in  knots 
per  hour  into  velocities  expressed  in  feet  per  second),  then  by  2325.2  (the  width  of 
each  partial  section)  and  by  0.9  (the  empirical  factor  to  reduce  to  mean  velocity) 
and  by  .97437  (because  the  flow  is  not  exactly  normal  to  the  section),  gives 

489.5  X  1.689  X2325.2  X  0.9  X  .97437=1,685,812 
cubic  feet  per  second  which  cross  this  section  at  the  time  of  strength  of  flood  or 
ebb.    This  multiplied  by  14,233  gives  23,944,162,000  cubic  feet  as  the  tidal  volume 
passing  the  section  on  a  flood  or  ebb  period  of  6  lunar  hours. 

♦Should  be  "Centennial  Tower."    E.  F.  R. 
tEncyclopacdia  Britannica,  Vol.  12,  pp.  509,  510. 

Darcy  and  Bazin:  Recherches  Hydrauliques  (Atlas),  Plates  19-23. 

Merriman:  A  Treatise  on  Hydraulics,  4th  Ed.,  Art.  113. 

Bovey:  A  Treatise  on  Hydraulics,  2d  Ed.,  p.  259. 

Murphy:  Accuracy  of  Stream  Measurements,  Water-Supply  and  Irrigation  Paper  No.  95,  p.  138. 


598        DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

TABLE  CXII 
New  York  Harbor,  N.  Y. 


Computation  op  Flood  and  Ebb  Volumes,  Including  Non-Tidal  Discharges 


i  otai  noou 

1  OL8.1  COD 

f  1 

W 

(7) 

W 

volume 

n  1 1 

volume 

ft  9\ 

A 

c 

A  ViS 

V  A2 

cos-«(-^) 

Ccos-M  i-J 
x  A  ' 

(6) -(8) 

(9)  X  14233 

(2)  X  44714 

(10)  +  (11) 

Sec 

tion  between 

Sandy  Hook 

and  Con 

ey  Island. 

January . . . 

1685812 

22281 

1685660 

1 

5576 

34705 

1650955 

23498043000 

996256000 

24494299000 

February. . 

u 

17449 

1685711 

1 

5604 

27227 

1658484 

23605203000 

780200000 

24385403000 

March  

u 

63159 

1684632 

1 

5333 

96842 

1587790 

22599015000 

2824058000 

25423073000 

April  

a 

65444 

1684531 

1 

5320 

100260 

1584271 

22548929000 

2926258000 

25475187000 

May 

U 

33829 

1685475 

1 

5507 

52459 

1633016 

23242717000 

1512638000 

24755355000 

June  

u 

27476 

1685593 

1 

5545 

42711 

1642882 

23283140000 

1228568000 

24511708000 

July  

u 

17624 

1685728 

1 

5604 

27500 

1658228 

23601559000 

788054000 

24389613000 

August. . . . 

a 

15734 

1685745 

1 

5615 

24569 

1661176 

23643518000 

703564000 

24347082000 

September. 

it 

17895 

1685711 

1 

5602 

37920 

1657791 

23595339000 

800174000  24395513000 

October... . 

(( 

24894 

1685626 

1 

5560 

28735 

1646891 

23440200000 

1113116000 

24553316000 

November. 

(f 

23035 

1685643 

1 

5571 

35868 

1649775 

23481248000 

1029990000 

24511238000 

December. . 

a 

29621 

1685559 

1 

5532 

46007 

1639552 

23335744000 

1324452000 

24660196000 

Mean  

u 

29870 

1685542 

1 

5531 

46391 

1639151 

23330036000 

1335556000 

24665592000 

♦23322888000 

*24658499000 

Winds 

The  accompanying  tables  and  diagranif  show  the  results  of  wind  observations  taken 
hourly  on  Ambrose  Channel  light  vessel,  No.  87,  Lat.  40°  28'  (02"),  Long.  70°  50'  (01") 
from  November  5, 1912,  to  February  3, 1913.  The  velocities  are  expressed  in  statute  miles 
per  hour,  and  the  directions  are  magnetic.  On  the  diagram  the  heavy  lines  represent 
velocities  in  magnitude  and  in  direction,  the  letters  in  the  circumference  of  the  circle 
showing  the  point  of  the  compass  from  which  the  wind  blows.  The  distance  from  the 
center  of  the  diagram  to  the  frequency  curve  represents,  when  scaled  off  according  to  the 
scale  on  the  diagram,  the  number  of  days  in  the  observation  period  of  91  days  (24- 
hour  periods),  during  which  the  wind  was  blowing  from  the  direction  specified  in 
the  circumference  of  the  circle. 

The  maximum  velocity  for  each  principal  direction,  as  recorded  during  this  period 
of  91  days,  is  given  at  the  end  of  the  table  of  hourly  observations. 

The  general  direction  of  the  wind  for  New  York,  Setauket  and  Asbury  Park, 
taken  from  Prof.  A.  J.  Henry's  Climatology  of  the  United  States  is  given  in  a  separate 
table.  It  is  probable  that  the  Weather  Bureau  could  furnish  much  additional  informa- 
tion at  these  three  places  should  it  be  wanted. 

These  values  are  the  average  for  the  flood  and  ebb  volumes  for  the  12  months. 
A  =  rate  of  maximum  tidal  flow  through  given  cross-section  (cubic  feet  per  second). 
C  =*  rate  of  run-off  (cubic  feet  per  second),    f  l~TC* 

Total  flood  volume  =  14233  X  A V    ~A*  *  C  cos^  (C/A)      1  | 

"      ebb       "      =  14233  X  {  "         }  +  44714  C. 

The  angle  whose  cosine  is  C/A  is  expressed  in  radians. 
fNot  reproduced. 


CORRESPONDENCE— STABILITY  OF  OUTLET  ISLAND  599 


•    TABLE  CXIII 
Prevailing  Winds 


From  Henry's  Climatology  of  the  United  States. 
Monthly,  Seasonal  and  Annual  Means. 


New  York,  N.  Y. 

Setauket,  N.  Y. 

Asbury  Park,  N.  J. 

Lat.  40°  43'  N. 

Lat.  40°  57'  N. 

Lat.  40°  13'  N. 

Month 

T  r\nrr    TA0  /W  W 

XjOng.  11    UU  W. 

jjong.  /o  uo  w. 

T  c\T\rr    7A°  fMY  W 

jLiOng.  /     uu  vv . 

Direction  of 

Direction  of 

Direction  of 

prevailing  wind 

prevailing  wind 

prevailing  wmd 

December  

N  W. 

TIT 
W. 

NW. 

January  

NW. 

W. 

NW. 

February . 

NW. 

W. 

NW. 

XTTTT 

NW. 

tt  r 

w. 

NW. 

March  

XTTTT 

NW. 

w. 

NW. 

April  

NW. 

w. 

SE. 

May  

NW. 

w. 

SE. 

NW. 

w. 

SE. 

June  

SW. 

w. 

SE. 

July  

SW. 

S. 

SE. 

NW. 

s. 

SE. 

Summer  Mean  

SW. 

s. 

SE. 

NW. 

s. 

NE. 

NW. 

NW. 

NE. 

NW. 

w. 

NW. 

NW. 

NW. 

NE. 

Annual  Mean  

NW. 

w. 

NW. 

SE. 

The  Direction  of  Wave  Travel 

While  we  have  no  observations  on  this  subject,  the  directions  taken  by  Sandy 
Hook,  Coney  Island  and  Rockaway  Beach  show  that  the  waves  which  produce  the 
greatest  littoral  drift  of  sand  or  gravel  are  from  the  direction  of  the  open  ocean,  not- 
withstanding the  fact  that  the  prevailing  winds  are  westerly. 

For  the  three  months  during  which  winds  were  observed  at  Ambrose  Channel 
light  vessel  (Nov.,  1912,  to  Feb.,  1913)  there  occurred  no  heavy  easterly  gale. 

Depth  to  Which  Wave  Action  Extends 

Wave  action  sufficient  for  preventing  the  rapid  deposition  of  matter  in  suspen- 
sion may  extend  to  considerable  depths,  possibly  to  the  hundred-fathom  line.* 

Wave  action  sufficient  for  agitating  sand  may  extend  to  a  depth  of  75  to  90  feet. 
It  is  said  that,  off  Nantucket  Shoals  where  the  depths  are  as  above,  sand  is  "fre- 
quently left  on  deck  by  a  sea  which  has  broken  on  board."f 

For  Lake  Superior  the  deposition  of  sand  upon  piers  and  breakwaters  indicates  a 
wave  agitation  down  to  30  feet  or  more.J 

"At  the  harbor  of  refuge,  Milwaukee  Bay,  Wis.,  it  was  found  as  a  result  of  one 
winter's  experience  that  the  limit  of  wave  disturbance  for  half-ton  stones  was  about 
13  feet  below  the  water  surface,  and  for  stones  of  250  pounds  more  than  20  feet,  the 
depth  of  the  water  being  about  30  to  35  feet."  § 

*Vaughan  Cornish:  Waves  of  the  Sea  and  Other  Water  Waves,  Ch.  V. 

tCapt.  D.  D.  Gaillard:  Wave  Action  in  Relation  to  Engineering  Structures,  p.  138. 

tfbid.,  p.  142.        §Ibid.,  p.  140. 


600 


DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


FIG.  31—1844 


W.  H.  Wheeler:  A  Practical  Manual  of  Tides 


Depth  at  Which  Waves  Break 

Waves  coming  from  deeper 
water  usually  break  when  the  un- 
disturbed depth  is  reduced  to  about 
the  height  of  the  wave  from  trough 
to  crest.  The  ratio  depth  -=-  height 
is  generally  somewhat  greater  than 
unity.  For  an  on-shore  wind  this 
ratio  is  greater  than  for  an  off- 
shore wind. 

The  following  are  a  few  refer- 
ences to  this  subject : 

Capt.  D.  D.  Gaillard:  Wave 
Action  in  Relation  to  Engineering 
Structures,  Ch.  VII. 

Vaughan  Cornish:  Waves  of 
the  Sea  and  Other  Water  Waves 
(English  Edition,  1910),  pp.  166- 
175. 

and  Waves,  pp.  122-124. 


Coastline  and  Depth  Changes 

The  following  are  a  few  references  to  matter  which  relates  to  changes  in  coast- 
line and  depth  in  Lower  New  York  bay  and  vicinity: 

General  for  Lower  Bay 

Appendix  No.  11,  Report  for  1895  gives  a  list  of  original  topographic  and  hydro- 
graphic  sheets.    These  sheets  can  be  consulted  at  this  office. 

Various  editions  of  Chart  No.  369,  particularly  the  editions  of  1844-45,  1857, 
1874,  1889,  1905,  and  latest  edition 
1912.  See  the  accompanying  phota- 
stat  copies.*  The  plane  of  refer- 
ence used  in  the  1844-45  edition 
was  about  low  water  springs;  this 
plane  as  then  determined  at  Sandy 
Hook  was  0.8  foot  lower  than  the 
plane  of  mean  low  water. 

Roclcaivay  Inlet 

Report  of  the  Jamaica  Bay  Im- 
provement Commission  (1907), 
Plates  I  and  II. 


Sandy  Hook 

Coast  Survey  Report,  1854, 
Sketch  93. 


*See  Figs.  31-35. 


FIG.  32—1874 


CORRESPONDENCE— STABILITY  OF  OUTLET  ISLAND 


601 


FIG.  33—1889 


Coast  Survey  Report,  1856, 
pp.  263-4. 

Coast  Survey  Report,  1873, 
Sketch,  p.  110. 

Lt.  C.  H.  Davis :  A  memoir 
upon  the  geological  action  of  the 
tidal  and  other  currents  of  the 
ocean,  text  and  Plate  3.  Mem.  of 
the  Am.  Acad,  of  Arts  and  Sci., 
Vol.  IV  (1849). 

Matter  in  Suspension 

From  the  table  giving  the  flood 
and  ebb  discharge  across  the  Sandy 
Hook  to  Coney  Island  section,  it 
can  be  readily  inferred  that  matter 
in  suspension  will  be  gradually 
carried  seaward  unless  deposition 
should  occur.  This  is  prevented  by 
the  wave  agitation  common  to  this  and  similar  localities.  That  such  matter  is  not  ex- 
tensively or  permanently  deposited  can  be  seen  from  the  character  of  the  bottom,  which 
in  no  case  is  marked  upon  the  charts  as  being  covered  with  a  layer  of  mud. 

Further  inland  where  the  waters  are  more  protected,  as  in  Raritan  Bay  and  near 
the  coast  of  Staten  Island,  the  bottom  is  more  or  less  muddy. 

Accumulation  op  Sand  at  the  Ends  op  the  Island 

The  effect  of  an  obstruction  like  the  proposed  island  upon  the  deposition  or 
rather  the  accumulation  of  matter  is  somewhat  problematic. 

It  is  reasonable  to  suppose  that  sand  will  accumulate  at  both  the  inner  and  outer 

(i.  e.,  westerly  and  easterly)  ends 
of  the  island  whichever  of  the  two 
suggested  positions  may  be  chosen, 
but  that  the  tendency  to  accumu- 
late will  be  greater  at  the  inner 
end  than  at  the  outer.  The  accu- 
mulation would  probably  be  less 
for  the  position  near  the  Fourteen 
Foot  Channel  than  for  the  posi- 
tion further  east,  because  of  the 
rather  swift  currents  occurring  in 
this  channel. 

That  sand  will  accumulate  at 
the  inner  (western)  and  outer 
(eastern)  ends  of  the  island,  there 
is  probably  no  doubt.  The  amount 
will  be  greater  at  the  inner  end 
than  at  the  outer,  because  the  lat- 
ter is  more  exposed  to  wave  action. 


FIG.  34—1912 


602 


DATA  RELATING  TO  THE  PROTECTION  OP  THE  HARBOR 


In  fact,  during  such  storms  as  may  give  rise  to  violent 
wave  action,  a  considerable  portion  of  the  sand  accumu- 
lation at  the  exposed  end  of  the  island  may  be  removed. 
How  far  below  the  low  water  line  such  action  may  leave 
the  wall  of  the  island  free  from  sand  is  uncertain. 

The  currents  in  the  Fourteen  Poot  Channel  are  of 
sufficient  strength  for  dissipating  any  accumulation  of 
sand  which  may  tend  to  take  place  at  points  within  their 
reach. 

The  following  references  may  be  of  some  interest 
in  connection  with  this  topic : 

Vaughan  Cornish :  Waves  of  the  Sea  and  Other 
Water  Waves  (1910),  Ch.  V. 

Lt.  C.  H.  Davis:  Memoir  upon  the  Geological 
Action  of  Tidal  and  Other  Currents  of  the  Ocean.  Mem.  Am.  Acad.  Arts  and  Sci.  Vol. 
IV  (1849). 

Suggestions  Concerning  the  Location  of  the  Island 

The  more  westerly  of  the  two  indicated  locations  has  the  advantage  of  being  pro- 
tected by  a  stretch  of  shallow  water  lying  southeastward  of  Fourteen  Foot  Channel. 
This,  acting  as  a  submerged  breakwater,  will  greatly  reduce  the  size  of  the  waves.  On 
the  other  hand,  the  proximity  to  Fourteen  Foot  Channel  is  objectionable  because  the 
tendency  of  the  currents  in  this  channel,  taken  in  connection  with  the  wash  of  the 
waves,  might  be  to  undermine  the  mound  or  wall  surrounding  the  island  unless  the 
foundations  were  carried  down  to  a  depth  of  about  35  feet  below  mean  low  water,  or 
the  depth  of  the  channel.  By  placing  the  island  further  from  this  channel,  say  a  dis- 
tance equivalent  to  the  indicated  width  of  the  island,  there  seems  to  be  no  reason 
why  this  objection  would  not  be  overcome  in  a  satisfactory  manner.  A  comparison 
of  the  soundings  at  and  near  the  point  whose  position  according  to  a  recent  chart  is 
40°  32'  N.  and  74°  00'  W.,  indicates  that  the  northern  edge  of  this  channel  has  moved 
southward  rather  than  northward  since  the  surveys  underlying  the  1844  edition  of 
chart  No.  369  were  made.  The  longitudes  on  this  chart  are  reckoned  from  the  City 
Hall,  New  York.  On  recent  editions  of  this  chart,  a  depth  of  36  feet  below  mean  low 
water  occurs  near  the  above-mentioned  point.  On  the  1844  edition  the  greatest  depth 
shown  is  30  foet  below  low  water  springs,  which  in  this  case  signifies  about  31  feet 
below  mean  low  water.  In  other  words,  the  channel  has  near  this  point  become  deeper 
by  5  feet.  (It  may  be  noted  that  the  1844  edition  shows  a  patch  marked  "Dry  at  low 
water"  lying  about  one  nautical  mile  north  of  this  point.  Recent  editions  show  the 
least  depth  to  be  3  feet  below  mean  low  water.) 

The  principal  objection  to  the  more  easterly  one  of  the  two  suggested  locations 
is,  of  course,  the  exposure  to  wave  action  from  the  southeast. 

Breakwater  Designing 

The  following  are  a  few  references  to  breakwater  designing  and  similar  matters : 
Brysson  Cunningham :  A  Treatise  on  the  Principles  and  Practice  of  Harbour  En- 
gineering, Ch.  VI.    London,  1908. 

Thomas  Stevenson :  The  Design  and  Construction  of  Harbors,  Ch.  VI.  Edin- 
burgh, 1886. 


CORRESPONDENCE— STABILITY  OF  OUTLET  ISLAND 


603 


De  Cordenioy :  Ports  Maritimes,  Ch.  XXXI.   Paris,  1908. 

Law  and  Burnell :  The  Rudiments  of  Civil  Engineering,  Ch.  VII.    London,  1882. 

Thomas  Stevenson  in  Ency.  Brit.,  9th  Ed.    Article  "Harbours." 

International  Engineering  Congress,  1904.  Trans.  Am.  Soc.  of  Civil  Engineers, 
Vol.  54,  Part  A  (1905).  Papers  Nos.  6-15  and  discussion,  pp.  137-451.  In  particular, 
Paper  No.  12,  Harbors  on  Lakes  Erie  and  Ontario;  Paper  No.  13,  Harbors  on  Lake 
Superior,  particularly  Duluth-Superior  Harbor;  Paper  No.  14,  Seacoast  Harbors  in 
the  United  States;  Paper  No.  15,  The  Delaware,  Sandy  Bay  and  San  Pedro  Break- 
waters. 

Louis  Y.  Schermerhorn :  Breakwater  Construction  of  the  American  Coast.  Pro- 
ceedings of  the  Engineers'  Club  of  Philadelphia,  Vol.  14  (1897),  pp.  205-228. 

Emil  Low:  The  Breakwater  at  Buffalo,  N.  Y.  Trans.  Am.  Soc.  of  Civil  Engineers, 
Vol.  52  (1904),  pp.  73-214. 

The  Sandy  Bay  Breakwater,  National  Harbor  of  Refuge,  Cape  Ann,  Mass.  Eng. 
News,  Vol.  55  (1906),  pp.  258,  259. 

Proposed  Improvements  of  the  Southwest  Pass  at  the  Mouth  of  the  Mississippi. 
Eng.  News,  Vol.  43  (1900),  pp.  117,  118. 

William  Starling:  The  Improvement  of  the  South  Pass  of  the  Mississippi  River. 
Eng.  News,  Vol.  44  (1900),  pp.  121-125. 

William  Starling:  The  Projected  Improvement  of  the  Southwest  Pass.  Eng.  News, 
Vol.  44  (1900),  pp.  222-229. 

Examination  and  Survey  of  St.  Johns  River,  Florida.  House  of  Representatives, 
Doc.  No.  611,  61st  Cong.,  2d  Session. 

Maj.  J.  C.  Post:  Improvement  of  Willamette  and  Lower  Columbia  Rivers  and 
Their  Tributaries.  Ann.  Report  of  the  Chief  of  Engineers,  U.  S.  Army,  1895,  Pt.  5, 
App.  UU,  pp.  3551-3608. 

B.  S.  White:  Breakwaters  and  Plans  for  Breakwater  Extension  at  Agate  Bay, 
Two  Harbors,  Minn.  Journal  of  the  Association  of  Engineering  Societies,  Vol.  28 
(1902),  pp.  171-194. 

Max  E.  Schmidt:  The  South  Pass  Jetties.  Transactions  of  the  American  Society 
of  Civil  Engineers,  Vol.  VIII  (1879),  pp.  189-226. 

Permanency  of  a  Proposed  Island 

The  island  in  question  is  supposed  to  contain  about  50  acres,  to  be  constructed 
of  sand  enclosed  within  a  riprap  wall  about  250  feet  wide  at  the  bottom  and  60  feet  at 
the  top ;  and  to  reach  a  height  about  18  feet  above  low  water.  Its  location  is  supposed 
to  be  one  of  the  two  shown  upon  the  accompanying  blue-print.* 

Of  course,  it  may  be  said  in  advance  that  the  stability  will  depend  upon  the  size 
of  the  blocks  of  stone  constituting  the  riprap  and  upon  what  slopes  are  given  to  the 
outer  or  water  faces  of  the  wall  or  mound.  Both  of  these  items,  and  especially  the 
first,  would  have  to  be  more  definitely  specified  before  any  positive  answer  could  be 
given. 

The  depths  at  and  near  the  proposed  location  of  the  island  are  generally  less 
than  16  feet,  and  so  there  is  no  doubt  about  wave  agitation  extending  to  the  bottom 
at  times  when  the  waves  coming  in  from  the  ocean  reach  considerable  size.  Because 
the  depth  of  water  is  considerably  less  than  the  lengths  of  such  waves,  these  do,  in 
a  measure,  lose  the  character  of  deep-water  waves  and  begin  to  resemble  long  waves 
*Not  reproduced. 


604 


DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


or  waves  whose  horizontal  motion  is  alike  from  top  to  bottom.  Consequently,  there 
is  no  plane  or  depth  of  "rest,"  say  15  feet  below  mean  low  water.  Such  a  plane  is 
often  found  convenient  in  breakwater  design  where  the  depths  are  greater  than  those 
now  under  consideration.  Between  this  plane  and  low  water  the  slope  of  the  seaward- 
face  is  frequently  taken  as  about  1  on  3;  below  this  plane  the  rubble  mound  may  be 
built  to  a  steeper  slope,  thus  leading  to  an  economy  of  material.  In  the  present  case 
it  would  seem  to  be  best  to  have  the  same  slope,  say,  1  on  3  or  1  on  2y2,  from  low 
water  level  down  to  the  bottom.  Moreover,  the  slope  should  be  faced  all  the  way  down 
with  rather  large  revetment  stones.  Those  used  in  the  Buffalo  breakwater  weighed 
about  6*4  tons  each.* 

There  seems  to  be  no  reason  why  the  slope  of  the  interior  face  may  not  be  quite 
steep,  say,  1  on  1,  or  1  on  iy2,  from  the  bottom  up  to  mean  low  water.  Above  this 
plane  the  slope  might  be  even  steeper  than  1  on  1. 

On  the  outer  or  exterior  face,  the  greatest  effect  of  wave  action  would  doubtless 
occur  at  and  above  the  low  water  level.  From  this  plane  up  to  the  top  of  the  struc- 
ture, the  steepness  is  usually  greatly  increased,  thus  making  a  saving  of  material. 
At  the  same  time,  stones  of  comparatively  large  dimensions  are  required  in  order  to 
withstand  wave  action.  Too  great  steepening,  however,  would  cause  an  increase  in 
wave  action  on  the  riprap  wall  just  below  the  line  where  such  increase  in  steepness 
begins.  For  in  the  case  of  a  sea-wall  built  upon  a  rubble  mound,  it  has  been  found 
that  the  rubble  near  the  wall  is  rapidly  worn  away  by  the  waves.f 

The  breakwaters  at  Buffalo,!  National  Harbor  of  Refuge  in  Delaware  Bay,§  and 
at  Sandy  Bay,||  seem  to  constitute  the  best  examples  for  the  case  under  consideration. 

The  works  of  Cunningham,  Stevenson,  Law  and  Burnell,  and  Gaillard  already 
mentioned  by  title,  give  numerous  illustrations  of  the  destructive  effects  of  waves 
upon  structures  composed  wholly  or  partially  of  rubble  work. 

A  profile  of  the  jetty  at  the  mouth  of  the  Columbia  River  shows  the  amount  of 
rock  washed  away  from  October  to  December,  1893. 

The  following  quotations  are  added  as  having  an  important  bearing  upon  this 
mode  of  construction. 

"The  disturbing  influence  of  waves  is  most  keenly  felt  between  the  levels  of  high 
and  low  water,  and  it  is  in  this  region  that  the  most  trying  ordeals  of  a  breakwater 
are  experienced.  A  difficulty  underlying  the  situation  is  that  in  proportion  as  the 
slope  is  flattened  to  maintain  its  equilibrium,  the  disruptive  effort  of  the  wave  is 
fostered  and  increased.  Hence  the  introduction  of  huge  blocks  and  monoliths  to 
withstand  impact.  These  blocks,  which  rarely  weigh  less  than  25  or  30  tons  apiece, 
and  often  considerably  more,  may  be  deposited  either  in  courses  or  at  random.  In 
the  former  case,  they  may  be  stepped  so  as  to  form  a  general  inclination  of  1  to  1; 
but  if  deposited  at  random,  a  flatter  slope  will  be  necessary. 

"The  blocks,  when  artificial,  are  generally  made  in  the  form  of  rectangular  solids : 
parallelopipeds  in  preference  to  cubes;  and  they  should  be  laid  as  headers — that  is, 

•Emile  Low,  L  c,  p.  133. 

fLaw  and  Burnell,  1.  c,  pp.  392,  393  and  397. 

JEmile  Low,  1.  c. 

§Louis  Y.  Schermerhorn,  1.  c,  p.  219. 

International  Engineering  Congress,  1904,  Paper  No.  15. 
||Engineering  News,  Vol.  55  (1906),  pp.  258,  259. 

Louis  Y.  Schermerhorn,  1.  c,  p.  213. 

International  Engineering  Congress,  1904,  Paper  No.  15. 
IfMaj.  J.  C.  Post,  1.  c,  opp.  p.  3560. 

See  also  Paper  No.  14,  p.  316,  International  Engineering  Congress. 


CORRESPONDENCE— STABILITY  OF  OUTLET  ISLAND 


605 


with  their  ends  facing  the  line  of  wave  action.  In  this  way  the  minimum  face  area 
is  exposed  to  the  stroke,  and  there  is  the  maximum  resistance  to  overturning. 

"Natural  blocks  are  heavier  per  unit  volume  than  the  majority  of  artificial  blocks, 
and,  for  this  reason,  have  claims  to  preference.  They  are  also  less  liable  to  disin- 
tegration, but  they  are  difficult  to  procure  economically  to  large  dimensions,  and 
their  irregular  shapes  render  it  impossible  to  bed  them  systematically.  They  have  a 
tendency,  also,  towards  becoming  rounded  like  boulders,  and  this  does  not  improve 
their  steadiness  in  situ."* 

"Breakwaters  built  of  rubble,  although  expensive  in  upkeep,  are  suitable  for  very 
sheltered  sites  in  shallow  water,  provided  good  and  cheap  material  is  procurable. 
This  type  is  not  affected  by  the  muddy  or  soft  nature  of  the  sea  bottom. 

"When  the  structure  is  exposed  to  very  heavy  seas,  the  rubble  type  of  mole  can 
still  be  adopted,  under  the  conditions  mentioned  above,  provided  a  revetment  of  con- 
crete blocks  is  added  outside  down  to  a  certain  depth.  The  method  of  depositing 
these  blocks  at  random  appears  the  best  as  regards  resistance  and  maintenance,  on 
condition  that  the  profile  of  the  protected  slope  is  so  designed  that  it  will  shear  the 
waves  at  sea-level.  On  the  other  hand,  the  method  of  setting  the  blocks  in  regular 
courses  offers  serious  objections,  as  they  are  liable  to  be  disturbed  by  the  settlement 
of  the  rubble  base  and  to  be  completely  destroyed  during  gales,  and,  in  any  case,  they 
cannot  be  maintained  in  good  condition  without  abandoning  the  principle  of  the  sys- 
tem itself. 

"Breakwaters  with  a  rubble  hearting  and  a  double  revetment  of  protecting 
blocks,  laid  in  regular  courses,  are  not  at  all  reliable  in  very  heavy  seas,  but  they  can 
render  very  useful  service  in  sheltered  sites  and  in  waters  of  moderate  depth,  espe- 
cially if  the  works  are  not  of  very  great  importance. 

"Breakwaters  with  vertical,  or  almost  vertical  sides,  are  very  suitable  for  mod- 
erate depths  and  hard  sea-beds,  where  there  is  no  fear  of  the  undermining  effect  of  the 
backwash  and  currents.  They  are  very  expensive  and  consequently  inapplicable  to 
unimportant  works. 

"The  composite  type  of  breakwater,  consisting  of  a  base  formed  by  a  loose  rubble 
mound,  surmounted  by  a  vertical  superstructure,  is  peculiarly  suitable  for  tidal  seas 
and  for  seas  with  a  slight  tidal  rise  and  fall,  provided  the  water  in  that  case  be  very 
deep.  In  the  case  of  tidal  seas,  there  is  no  objection  to  stopping  the  superstructure 
at  low  water  level. f 

"A  very  obvious  and  very  important  point  regarding  the  stability  of  such  a  struc- 
ture as  a  breakwater  has  reference  to  the  depth  below  low  water  at  which  the  waves 
cease  to  exert  any  considerable  impact  upon  the  materials  on  which  the  superstruc- 
ture rests.  It  was  found  at  Wick  that  the  very  anomalous  waves  which  assailed  that 
work  did  not  disturb  any  of  the  rubble  base  at  a  lower  depth  than  18  feet  under  low 
water.  I  am  therefore  of  opinion  that  a  level  of  from  18  to  20  feet  below  low  water 
may  be  safely  assumed  as  that  of  practical  stability.  I  conceive  that  the  safest  and 
most  economic  profile  of  construction  is,  as  is  shown  in  Fig.  15,  a  mass  consisting  of 
large  rubble  extending  to  within  20  feet  of  low  water;  when  the  base  has  been 
brought  up  to  this  level,  blocks  of  concrete,  weighing  from  100  to  200  tons,  should 
be  deposited  on  the  top  and  outer  or  seaward  surface  of  the  rubble  base,  till  they  come 
above  low-water  level.  Betwixt  the  spaces,  at  the  top  of  these  blocks,  bags  of  con- 
crete should  be  placed  so  as  to  form  a  level  platform  above  low-water  level.  Upon 

•Cunningham,  L  c,  pp.  136,  137. 

tQuoted  by  Cunningham,  1.  c,  pp.  140,  141. 


606        DATA  E ELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


this  a  solid  mass  of  concrete  in  situ,  should  extend  from  end  to  end  of  the  break- 
water, which  should  not  be  less  than  10  feet  above  high  water,  and  about  45  feet  in 
breadth.  A  structure  designed  on  these  principles  will,  I  think,  be  found  able  to 
resist  the  force  of  the  sea  in  any  situation,  provided  the  sea  slope  be  of  sufficient 
extent.  The  design  shown  in  Fig.  15  is  that  proposed  by  Messrs.  Stevenson  for  the 
harbor  of  refuge  at  Peterhead. 

"Level  of  Conservation  of  Rubble. — If  we  further  keep  in  view  that  any  settle- 
ment of  the  foundation  is  far  more  perilous  to  a  vertical  than  to  a  sloping  wall,  there 
seems  good  ground  for  believing  that  the  ordinary  method  of  forming  the  low-water 
parts  of  deep  harbors  of  large  masses  of  rubble  stone  or  of  concrete  blocks,  is,  in  most 
circumstances,  the  best  and  cheapest  kind  of  construction  when  a  vertical  wall  is  to 
adopted.  Loose  rubble  or  blocks  of  concrete,  after  being  acted  upon  by  the  waves, 
are  less  liable  to  sink,  or  to  be  underwashed,  than  when  a  vertical  wall  is  founded 
upon  a  soft  bottom.  Loose  concrete  blocks  above  low  water  form  an  excellent  pro- 
tection to  the  upright  wall.  Two  precautions  should,  however,  be  kept  in  view :  First, 
the  wall  should  be  founded  at  a  sufficiently  low  level  to  prevent  underwashing.  A 
depth  of  from  12  to  15  feet  under  low  water  was  pointed  out  by  the  late  Mr.  J.  M. 
Rendel  as  the  level  below,  which  the  waves  did  little  or  no  damage  to  pierres  perdues. 
Sir  John  Rennie  indeed  considered  that  there  was  little  or  no  effect  at  a  fathom  and 
a  half.*  No  works  executed  at  an  earlier  date  than  those  at  Wick  had  been  founded 
at  a  lower  level  than  12  feet;  but  at  Pulteneytown,  where  the  rubble  is  more  exposed 
than  at  any  other  harbor,  Messrs.  Stevenson,  as  already  stated,  considered  it  advis- 
able to  found  the  wall  18  feet  below  low  water,  and  the  rubble  was  moved  down  to  18, 
and  at  Alderney  to  20,  feet  below  low  water.  Secondly,  in  all  cases  where  the  struc- 
ture is  to  act  simply  as  a  breakwater,  and  not  as  a  pier,  there  should  be  no  parapet, 
the  want  of  which  relieves  the  foundation,  as  was  observed  by  Mr.  D.  Stevenson  at  a 
harbor  work  where  a  breach  -had  been  made."f 

"Jetties  entirely  in  loose  rubble  work  are  principally  constructed  for  the  pur- 
pose of  destroying  the  force  of  the  waves  without  its  being  intended  to  make  them 
serve  for  the  purpose  of  assisting  the  maneuvers  of  vessels  entering  or  departing. 
Such  a  mode  of  construction  may  be  advisable  when  the  rough  materials  are  easily 
procured,  and  when  skilled  labor  is  exorbitantly  dear;  but,  as  a  general  rule,  it  will 
be  found  that  the  ultimate  expense  of  the  maintenance  of  such  works  will  more  than 
counterbalance  any  economy  in  the  original  outlay."J 

*Min.  Civ.  Eng.,  Vol.  VI,  p.  122. 
tThomas  Stevenson,  1.  c,  pp.  98-100. 
JLaw  and  Burnell,  1.  c,  pp.  425,  426. 


CHAPTER  VI 

DIGESTION  OF  SEWAGE  BY  THE  HARBOR  WATER  AND  THE  EX- 
HAUSTION OF  DISSOLVED  OXYGEN,  WITH  TABLES  OF 
OXYGEN  AND  OTHER  CHEMICAL  RESULTS 

SECTION  I 

ANALYTICAL  WORK  RELATING  TO  NEW  YORK  HARBOR 
In  the  present  chapter  the  principal  analytical  work  done  by  the  Commission  in 
its  studies  of  New  York  harbor  and  not  hitherto  published,  is  described.  Upon  the 
reorganization  of  the  Commission  in  1908  a  compilation  was  made  of  all  the  analyt- 
ical data  available  up  to  that  time  concerning  the  condition  of  the  harbor  waters,  and 
a  summary  of  the  results  was  published  by  the  Commission  under  the  title  of  "Digest 
of  Data  Collected  Before  the  Year  1908  Relating  to  the  Sanitary  Condition  of  New 
York  Harbor."  The  most  extensive  part  of  the  data  contained  in  the  digest  repre- 
sented the  work  done  by  the  New  York  Bay  Pollution  Commission  in  1904  and  1906. 
Bacterial  and  chemical  analyses  were  made  by  the  Pollution  Commission  and  had  been 
published  in  that  Commission's  report  to  the  Governor  of  the  State  of  New  York,  March 
31, 1905,  and  April  30,  1906.  The  total  number  of  samples  analyzed  was  about  165. 

The  Digest  of  Data  described  the  investigations  made  by  the  Metropolitan  Sewer- 
age Commission  in  1907,  these  including  the  only  anaiytical  results  made  by  this 
Commission  until  1909.  The  results  included  determinations  of  numbers  of  bacteria 
in  the  water  and  in  solid  matter  at  the  bottom  of  the  harbor,  presumptive  tests  for  the 
colon  bacillus  and  results  of  chemical  analyses  of  the  water.  There  were  755  samples 
of  water  in  which  the  numbers  of  bacteria  were  determined.  There  were  705  samples 
of  solid  matter  analyzed  for  bacteria  and  322  presumptive  tests  made.  There  were 
47  samples  analyzed  for  ammonia.  Other  chemical  tests  included  free  and  albuminoid 
ammonia,  chlorine  and  loss  on  ignition.  Color  and  turbidity  tests  were  made  on  about 
900  samples. 

The  Digest  described  brief  investigations  made  by  the  Department  of  Water 
Supply,  Gas  and  Electricity  in  1904  and  1905  to  determine  points  along  the  water 
front  at  which  to  locate  intakes  for  the  auxiliary  fire  service.  In  these  studies,  383 
samples  were  collected  and  analyzed  for  numbers  of  bacteria,  B.  coli,  free  ammonia, 
albuminoid  ammonia,  nitrites,  nitrates  and  chlorine. 

Investigations  of  the  water  of  the  Lower  Hudson  river  were  made  in  1903  by 
Whipple  in  connection  with  studies  for  an  additional  drinking  water  supply  for  the 
City  of  New  York.   The  data  collected  which  were  capable  of  showing  the  sanitary  con- 


608        DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

dition  of  New  York  harbor  was  small.  The  results  were  discussed  in  the  Digest  issued 
by  the  Sewerage  Commission. 

Finally,  the  Digest  contained  a  summary  of  the  investigations  of  the  condition  of 
the  Passaic  river  conducted  by  Hazen  and  Whipple  in  1906.  This  report  was  re- 
stricted in  scope  and  contained  little  information  relating  to  New  York  harbor. 

A  large  part  of  the  analytical  work  done  by  the  Metropolitan  Sewerage  Commis- 
sion since  1908  has  been  performed  with  the  oxygen  test.  The  method  of  making  this 
test  and  the  results  obtained  have  been  described  in  the  Commission's  reports,  always, 
however,  with  the  form  of  apparatus  originally  employed.  The  method  with  the  ap- 
paratus used  up  to  May,  1912,  is  best  shown  in  the  report  of  the  Commission  for 
August,  1912,  Part  III,  Chapter  III,  pp.  298-306.   The  old  apparatus  is  shown  in  Fig. 

85,  p.  305,  of  the  report  cited.  The  new  apparatus,  known  as  the 
Soper  Oxygen  Bottle,  from  having  been  devised  by  the  President  of 
the  Commission,  is  shown  in  Fig.  36  of  this  report. 

This  apparatus  consists  of  a  bottle,  usually  of  about  500  c.c. 
capacity,  with  a  long  funnel-shaped  lip.  A  stopper  which  is  convex 
at  the  bottom  fits  accurately  into  the  neck  and  when  in  place  per- 
mits about  15  c.c.  of  liquid  to  stand  in  the  funnel  without  overflow- 
ing. The  capacity  of  the  bottle  is  accurately  determined  with  the 
stopper  in  place. 

In  use  the  bottle  is  filled  to  the  beginning  of  the  funnel  with 

the  water  to  be  examined  and  the  stopper  is  set  down  in  place.  The 
FIG.  36 

excess  of  water  which  rises  in  the  funnel  is  poured  off.    The  stop- 

Soper  Oxygen 

Bottle  Per  *s  removed  and  to  the  bottle  of  about  500  c.c.  capacity,  6  c.c.  of 

a  standard  solution  of  ferrous  sulphate  are  delivered  by  a  pipette 
to  the  bottom  of  the  bottle  where  it  remains  unless  the  bottle  is  agitated.  The  stopper 
is  replaced  and  the  water  which  rises  in  the  funnel  is  poured  off.  Five  c.c.  of  sodium 
carbonate  solution  (200  grams  per  liter  of  water)  are  then  poured  into  the  funnel. 
The  stopper  is  cautiously  raised  sufficiently  to  allow  the  heavy  alkali  to  sink  through 
the  water  to  the  bottom  of  the  bottle,  where  the  reaction  producing  a  heavy  precipitate 
begins.  The  stopper  is  set  back  in  place,  the  water  in  the  funnel  is  poured  off  and  the 
bottle  is  shaken  until  the  free  oxygen  is  entirely  absorbed.  Ten  c.c.  of  a  50  per  cent, 
solution  of  sulphuric  acid  is  poured  into  the  funnel  and  the  stopper  raised  sufficiently 
to  permit  the  heavy  acid  to  diffuse,  discoloring  and  permitting  the  contents  of  the 
bottle  to  be  titrated.  Finally,  the  contents  are  poured  into  an  Erlenmeyer  flask  and 
titrated  with  permanganate  of  potash,  each  c.c.  of  which  represents  1  c.c.  of  oxygen. 
A  blank  determination  is  made  whenever  the  water  contains  much  organic  matter 


N?  84 

capacity  saocc. 

20"C 


ANALYTICAL  WORK  609 

or  sodium  chloride.  The  same  steps  are  followed  in  making  the  blank  as  in  making 
the  analysis  except  that  the  sodium  carbonate  is  omitted.  The  difference  between  the 
permanganate  required  by  the  blank  and  that  absorbed  in  the  actual  analysis  represents 
the  dissolved  oxygen  present. 

The  purpose  of  this  apparatus  is  to  permit  of  the  addition  of  reagents  to  the  bottle 
without  exposing  the  contents  to  the  air. 

The  reagents  used  are  as  follows: 

Standard  Ferrous  Sulphate.  This  is  prepared  by  dissolving  144  grams  of  Kahl- 
baum's  crystallized  ferrous  sulphate  in  water,  adding  15  cubic  centimeters  of  concen- 
trated sulphuric  acid  and  diluting  the  whole  to  3  liters. 

Standard  Sodium  Carbonate.  Prepared  by  dissolving  200  grams  of  sodium  car- 
bonate crystals  in  1  liter  of  water. 

Standard  Sulphuric  Acid.  Prepared  by  mixing  equal  parts  of  concentrated  sul- 
phuric acid  and  water. 

Standard  Potassium  Permanganate.  Prepared  by  dissolving  25.4  grams  of  potas- 
sium permanganate  in  water  and  diluting  to  4.5  liters.  This  reagent  is  standardized 
against  especially  prepared  Mohr'.s  salt. 

The  total  number  of  oxygen  analyses  made  from  1909  to  1914,  inclusive,  was  ap- 
proximately 3,710. 

The  Commission's  report  of  August,  1912,  contains  tabulations,  maps  and  diagrams 
showing  the  oxygen  and  other  analytical  work  done  up  to  the  time  that  report  went  to 
press.  In  addition  to  the  oxygen,  the  results  of  bacterial  analyses  and  microscopic  ex- 
aminations were  recorded. 

The  present  volume  describes  the  oxygen  results  obtained  by  the  Commission  sub- 
sequent to  those  recorded  in  the  1912  report.  The  same  method  of  tabulation  has  been 
preserved  and  the  diagrams  and  other  representations  which  were  introduced  in  1912 
have  been  followed  in  plotting  the  data  wherever  this  method  of  record  seemed  likely 
to  aid  in  comparing  and  comprehending  the  facts. 

No  bacterial  or  microscopic  analyses  were  made  by  the  Commission  after  those 
recorded  in  the  1912  report. 

A  feature  of  the  analytical  work  done  toward  the  end  of  the  Commission's  exist- 
ence was  the  making  of  chemical  examinations  of  the  kind  customarily  employed  in 
standard  sanitary  investigations,  the  object  being  to  afford  a  check  upon  the  oxygen 
work  and  obtain  data  concerning  the  behavior  of  the  nitrogen  compounds.  These  chem- 
ical examinations  included  analyses  for  free  and  albuminoid  ammonia,  nitrites  and 
nitrates. 

Before  making  the  nitrate  examinations,  considerable  time  was  spent  in  com- 


610        DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

paring  methods  for  this  test.  The  presence  of  salt  in  the  sea  water  so  interfered  with 
the  customary  nitrate  analysis  as  to  require  that  special  provision  be  made  for  over- 
coming the  difficulties. 

After  some  preliminary  investigation,  it  was  decided  to  test  the  two  most  promis- 
ing methods  for  the  electrolytic  reduction  of  nitrates  to  the  form  of  ammonia  and  the 
subsequent  estimation  of  the  ammonia  in  the  usual  way.  The  reduction  procedures 
which  were  compared  were  the  copper  zinc  method,  as  described  by  McGowan  ( See 
Part  V,  Vol.  IV,  Fourth  Report  Royal  Commission  on  Sewage  Disposal  of  Great 
Britain)  and  the  aluminum  foil  method,  as  recommended  by  the  Committee  on  Stand- 
ard Methods  of  Water  Analysis  of  the  American  Public  Health  Association.  Parallel 
tests  were  made  with  these,  using  sea  water,  harbor  water  and  land  water.  Definite 
weights  of  sodium  nitrate  were  added  and  the  increases  noted  by  analysis. 

The  results  of  the  research  show  that  nitrates  were  present  in  all  the  samples  and 
that  nitrates  in  sea  water  and  mixtures  of  sea  water  and  land  water  can  be  reliably 
determined  by  either  of  the  reduction  methods  tested.  The  data  obtained  in  these  ex- 
periments follow : 

TABLE  CXIV 

Amount  of  Nitrogen  Found,  as  Nitrate  in  Land,  Harbor  and  Sea  Water,  by  Re- 


duction—  (a)  with  Aluminum  Foil,  and  (b)  with  Copper  Zinc  Couple 


Source  of  Sample 

Parts  per 

Series  A 
Aluminum 
Reduction 

1,000,000 

Series  B 
Copper  Zinc 
Reduction 

Land  Water  

0.004,0 
0.291,0 
0.425,0 
0.520,0 
0.240,0 
0.160,0 
0.100,0 

0.366,0 
0.300,0 
0.445,0 
0.560,0 
0.260,0 
0.160,0 
0.180,0 

tt  tt 

u  U 

tt  « 

a  u 

TABLE  CXV 

Amount  op  Nitrogen  Found,  as  Nitrate  in  Land  and  Sea  Water  Charged  with 
Known  Quantities  of  KN03,  by  Reduction — (a)  with  Aluminum  Foil,  and 
(b)  with  Copper  Zinc  Couple 


Source  of  Sample 

Present 
Theoretically 

Parts  per  1,000,000 

Series  A 
Aluminum 
Reduction 

Series  B 
Copper  Zinc 
Reduction 

0.005,2 
0.138,0 
0.011,0 
0.005,5 
0.005,5 
0.010,0 
0.016,5 
0.035,0 

0.005,0 
0.127,0 
0.010,0 
0.005,0 
0.005,1 
0.010,0 
0.015,0 
0.033,0 

0.005,0 
0.131,0 
0.010,0 
0.004,5 
0.006,0 
0.007,5 
0.016,5 
0.035,0 

It  u 

u  u 

u  u 

tt  It 

It  tt 

u  tt 

ANALYTICAL  WORK  611 

As  a  consequence  of  this  research,  the  Commission  employed  the  reduction 
method  for  the  determination  of  nitrates  throughout  its  subsequent  work.  The  chemical 
examinations  are  fully  stated  in  the  tables  following  the  oxygen  results  here  given. 

In  connection  with  the  oxygen  and  other  analyses  of  the  harbor  water,  it  some- 
times became  desirable  to  make  incubation  tests  and  these,  in  properly  tabulated  form, 
are  appended  to  the  oxygen  results  which  are  stated  in  the  following  tables. 

The  data  here  published  are  capable  of  yielding  many  interesting  and  important 
facts  relating  to  the  harbor's  condition  and  particularly  to  the  phenomena  concerned 
in  the  digestion  of  the  sewage.  The  information  of  principal  value  is  believed  to 
have  been  extracted  during  the  course  of  the  work,  but  it  is  not  improbable  that  further 
careful  study  of  the  details  would  repay  the  care  and  time  expended. 

Since  the  Commission  was  reorganized  in  1908,  all  the  analytical  data,  in  common 
with  all  the  other  scientific  and  technical  facts  have  been  collated  and  tabulated  as 
the  work  progressed. 

The  Commission  considers  that  its  analytical  work  has  been  sufficiently  thorough 
and  comprehensive  to  afford  the  information  needed  for  definite  opinions  concerning 
the  condition  of  the  harbor  and  the  method  which  should  be  followed  for  its  improve- 
ment. It  would  be  desirable  to  repeat  some  of  the  investigations  from  year  to  year  to 
show  what  changes,  if  any,  occur.  The  system  which  should  be  followed  in  these 
studies  has  been  made  clear  by  the  work  which  has  been  done. 

Excepting  for  the  study  of  detailed  conditions  in  certain  localities  and  the  investi- 
gation of  special  problems,  it  will  be  sufficient  to  take  samples  at  the  principal  cross- 
sections  established  by  the  Commission  and  made  a  feature  of  its  final  work.  The 
analyses  need  not  be  either  numerous  or  elaborate.  The  determinations  of  dissolved 
oxygen  as  described  in  this  Commission's  reports  will  probably  afford  all  the  informa- 
tion necessary.  It  is  essential  that  the  method  of  analysis  should  be  the  same  or  at 
least  that  a  test  should  be  followed  which  is  as  free  from  error  as  that  which  the 
Commission  has  employed,  otherwise  the  results  will  not  be  strictly  comparable.  The 
utmost  pains  were  taken  by  the  Commission  in  selecting  and  testing  the  accuracy  of  its 
dissolved  oxygen  method  and  the  fullest  confidence  may  be  placed  in  this  test. 


612        DATA  RELATING  TO  THE  PROTECTION  OP  THE  HARBOR 


SECTION  II 

DIGESTION  OF  SEWAGE  BY  THE  HARBOR  WATER  AND 
THE  EXHAUSTION  OF  DISSOLVED  OXYGEN 

DIGESTION  OF  SEWAGE  IN  NEW  YORK  HARBOR 

From  an  early  period  in  its  career,  the  Commission  has  given  attention  to  the 
conditions  under  which  sewage  matters  would  disappear  when  discharged  into  the 
harbor  waters.  The  conditions  required  for  assimilation,  collectively  termed  the 
"phenomena  of  digestion,"  were  made  the  subject  of  experimental  investigation  in  the 
laboratory  and  in  the  open  harbor  water,  and  were  among  the  profitable  directions  in 
which  these  researches  were  carried. 

The  point  toward  which  the  Commission  was  working  in  these  experimental  and 
analytical  studies  was  an  understanding  of  the  circumstances  under  which  the  great- 
est use  could  be  made  of  the  harbor  for  the  reception  of  the  sewage  without  injurious 
consequences  to  the  public  health  and  welfare.  The  need  of  utilizing  the  harbor's 
digestive  capacity  was  apparent.  It  was  evident  that  engineering  works  capable  of 
carrying  the  sewage  to  a  distant  point  for  disposal,  or  plans  for  its  intensive  treat- 
ment, would  be  very  expensive.  Since  a  sanitary  disposal  of  the  sewage  was  to  be 
looked  upon  as  a  necessity  and  not  as  a  luxury,  it  was  necessary  to  confine  the  con- 
struction to  the  most  economical  works  which  would  answer  the  actual  requirements. 

Pollutions  from  the  docks  and  shipping  would  always  add  a  considerable  amount 
of  sewage  matters,  even  though  the  most  extensive  works  were  built  to  keep  the  land 
sewage  from  entering  the  harbor.  It  was  recognized  that  the  harbor  was  capable  of 
assimilating  large  quantities  of  sewage  materials  and  experience  here,  as  well  as  at 
other  points  known  and  visited  by  the  Commissioners,  pointed  to  the  possibility  of 
making  large  use  of  the  harbor's  digestive  capacity  for  sewage.  Obviously  certain  con- 
ditions which  produced  nuisance  and  injury  to  health  would  have  to  be  prevented.  If 
the  harbor  was  to  be  used  for  the  reception  of  a  large  part  of  the  sewage,  it  would  be 
necessary  to  make  a  scientific  use  of  the  natural  forces  by  which  the  objectionable 
matters  could  be  disposed  of. 

It  was  explained  in  the  Commission's  report  of  1910  that  freedom  from  evil  con- 
sequences attending  the  discharge  of  sewage  and  other  wastes  into  New  York  harbor 
depended  upon  the  bodily  transportation  of  a  part  of  the  refuse  matters  from  the 
harbor  to  sea  by  means  of  the  harbor  currents  and  the  assimilation  of  the  remainder 
by  the  water  itself.    Owing  to  the  backward  and  forward  oscillation  of  the  tide, 


DIGESTION  OF  SEWAGE  AND  EXHAUSTION  OF  OXYGEN  613 

the  seaward  transportation  is  irregular  and  the  amount  of  upland  water  poured 
into  the  harbor  by  the  rivers  is  insufficient  to  carry  the  sewage  wastes  promptly 
away.  The  ultimate  disposal  of  the  wastes  depends  largely  upon  the  assimilative 
capacity  which  the  Commission  has  termed  "digestion." 

The  Commission's  first  report,  dated  April  30,  1910,  contained  an  account  of  the 
bacterial  condition  of  the  harbor  waters  and  several  chapters  deal  with  the  phenom- 
ena and  assimilation  or  digestion  of  sewage  matters.  The  relative  intensity  of  pollu- 
tion was  shown  not  only  by  bacterial  studies,  but  by  analyses  of  the  dissolved  oxygen 
made  in  all  the  important  sections  into  which  the  harbor  was  divided.  The  deposits 
upon  the  harbor  bottom  were  studied  with  reference  to  the  intensity  of  their  pollution ; 
and  in  Chapter  X  there  was  given  a  discussion  of  the  diffusion  and  digestion  of  sewage 
in  the  harbor,  in  which  information  was  furnished  on  the  composition  of  the  polluted 
wastes  and  the  results  of  experimental  studies  on  diffusion  and  digestion  carried  out 
by  means  of  laboratory  tests,  the  discharge  of  large  volumes  of  sewage  into  the  harbor 
and  investigations  on  the  floatation  of  solid  objects. 

In  Chapter  X  of  the  1910  report  the  solids  of  sewage  were  discussed  under  the 
heads  of  those  which  sink,  those  which  float,  and  those  which  remain  suspended  in  the 
main  body  of  the  water  into  which  they  are  discharged.  The  liquid  portion  of  the 
sewage  was  considered  under  the  headings  of  oil  and  grease  and  the  liquids  which  are 
principally  concerned  with  the  depletion  of  oxygen. 

The  Commission's  report  of  August,  1912,  contains  a  further  discussion  on  the 
phenomena  of  digestion  in  Chapters  V  and  VI  of  Part  I,  and  of  the  state  of  the  water 
as  shown  by  the  dissolved  oxygen,  bacteria  and  microscopic  debris  in  Chapters  VII 
and  VIII. 

A  thorough  account  of  some  of  the  principal  phenomena  of  digestion,  especially 
as  they  relate  to  the  depletion  of  oxygen,  was  contained  in  the  report  of  Prof.  W.  E. 
Adeney  who  was  brought  to  America  from  England  by  the  Commission  for  the  purpose 
of  consultation  upon  this  topic.  Professor  Adeney's  report  with  respect  to  the  degree 
of  cleanness  which  is  sufficient  for  the  water  is  contained,  like  the  reports  of  seven 
other  eminent  experts  selected  by  the  Commission,  in  Chapter  III,  Part  II,  of  the 
1912  report. 

All  the  data  and  opinions  on  the  question  of  the  digestion  of  sewage  and  the  part 
which  oxygen  plays  in  this  phenomenon  are  not  to  be  found  in  the  references  there 
given.  For  example,  a  large  part  of  the  1912  report  (over  150  pages)  is  devoted  to  the 
dissolved  oxygen  question,  and  all  of  Part  III,  excepting  that  which  is  devoted  to  the 


614        DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

oxygen,  relates  to  the  microscopic  examinations  and  numbers  of  bacteria.  Scattered 
through  the  preliminary  reports  of  the  Commission  will  be  found  other  mention  of 
this  important  topic. 

Composition  and  Quantity  of  the  Sewage 

The  term  "sewage"  has  been  used  by  the  Commission  to  mean  the  wastes  which 
flow  from  dwelling  houses,  factories  and  streets  through  the  municipal  sewerage  sys- 
tems and  these  wastes  after  discharge,  whether  solid  or  liquid,  are  usually  referred  to 
as  sewage  materials. 

The  composition  of  the  sewage  represents  a  theoretical  standard  which  has  been 
assumed  for  New  York.  The  aggregate  quantity  of  sewage  materials  discharged  in 
1910  was  equivalent  to  255,000  tons  of  dry,  solid  matter,  all  of  which  was  capable  of 
offensive  putrefaction,  or  already  advanced  to  some  extent  toward  that  condition. 
One  ton  of  this  material  was  equivalent  to  about  50  tons  or  55  cubic  yards  of  wet 
sludge,  such  as  is  deposited  on  the  harbor  bottom  and  as  is  ordinarily  obtained  from 
sedimentation  basins.  It  thus  appears  that  there  is  discharged  each  year  into  the 
harbor  of  New  York  sewage  sufficient  to  produce  12,800,000  tons  of  sludge,  having  a 
bulk  of  14,000,000  cubic  yards. 

The  Suspended  Matters. — Fresh  sewage  taken  from  the  New  York  sewers  has  a 
dirty,  gray  color  and  an  unpleasant,  sweetish,  musty  odor.  It  contains  particles  of 
solid  matters  whose  identity  is  readily  recognizable  to  sight,  and  finer  particles  which 
collectively  produce  a  turbid  appearance  in  the  liquid.  Most  of  the  solid  particles  will 
pass  through  screens  having  meshes  of  one-eighth  of  an  inch.  Such  screens  as  are 
used  in  the  purification  of  sewage  upon  a  practical  scale  are  capable  of  removing, 
say,  15  per  cent,  of  the  suspended  matter,  this  removal  being  slightly  greater  or  con- 
siderably less,  depending  upon  the  fineness  of  the  screens  employed.  About  one-third 
of  the  suspended  matter  removed  by  screens  consists  of  paper  and  other  material 
which  is  not  readily  susceptible  to  decomposition. 

A  considerable  proportion  of  the  finer  material  is  in  a  semi-solid  colloid  condi- 
tion, which  causes  the  purification  of  sewage  to  be  attended  with  particular  difficulty. 

Upon  standing,  some  of  the  particles  settle  out  causing  a  dirty  grayish  or  blackish 
sludge  to  deposit. 

Under  usual  conditions  about  60  per  cent,  of  the  total  solids  in  sewage  are  in  sus- 
pension, and  about  one-half  of  these  can  be  removed  by  allowing  the  sewage  to  flow 


DIGESTION  OF  SEWAGE  AND  EXHAUSTION  OF  OXYGEN  615 

very  slowly  through  sedimentation  tanks  during  a  period  of  ahout  two  hours.  It  is  esti- 
mated that  ahout  one-half  of  the  resulting  sludge  consists  of  organic  matter  capable 
of  putrefaction.  By  adding  a  chemical  precipitant  before  the  sewage  is  settled,  about 
85  per  cent,  of  the  suspended  matter,  and  50  per  cent,  of  the  organic  matter  can  he 
removed  as  sludge. 

The  putrefiable  material  in  the  sewage  is  by  some  believed  to  be  largely  in  the 
sludge,  but  experiments  made  by  this  Commission  show  that  the  liquid  part  of  sewage, 
when  preserved  for  a  few  days  in  bottles,  will  use  up  the  contained  oxygen  and  produce 
the  characteristic  odors  which  may  be  expected  from  raw  sewage  when  preserved 
under  the  same  conditions.  There  is  as  much  organic  matter  in  solution  as  in  sus- 
pension in  the  sewage  produced  by  the  average  city,  but  the  fresher  the  sewage,  the 
larger  the  relative  amount  of  organic  matter  in  suspension  and  the  smaller  the  relative 
amount  in  solution. 

Of  the  total  amount  of  organic  matter  present  in  solid  or  suspended  form,  about 
one-half  is  nitrogenous.  Fats  and  soaps  are  sparingly  present  in  spite  of  appearances 
to  the  contrary. 

The  Commission  in  its  first  report  divided  the  solids  of  sewage  into  those  which 
sink  soon  after  the  sewage  is  discharged  into  the  harbor ;  second,  those  which  continue 
to  float  for  some  time  on  the  surface  of  the  water ;  and,  third,  those  which  are  long 
carried  in  suspension  in  the  body  of  the  tidal  streams.  Many  which  at  first  float  grad- 
ually become  broken  up  or  water-soaked  and  sink  beneath  the  surface  of  the  water, 
thus  passing  from  the  second  to  the  first  division  or  to  the  third. 

Turbidity  Due  to  Sewage  Discharges. — The  water  of  the  harbor  is  markedly  dis- 
colored and  rendered  turbid  where  the  sewers  discharge.  The  size  of  the  materials 
which  produce  the  turbid  appearance  varies  from  sub-microscopic  particles  up  to 
masses  whose  identity  can  immediately  be  distinguished  from  the  docks  and  vessels 
in  the  vicinity.  The  water,  which  is  generally  of  an  olive,  slightly  turbid  appear- 
ance, becomes  brownish  gray,  greasy  and  muddy  in  appearance.  The  boundaries  of  the 
sewage  stream  are  for  some  time  sharply  defined  in  the  surrounding  water.  When 
the  harbor  currents  are  sufficient  to  carry  the  sewage  promptly  away  from  the  out- 
fall, the  discolored  area  expands  and  fades  from  sight. 

The  discharge  of  sewage  is  generally  not  recognized,  except  for  the  grease  and 
larger  particles,  beyond  a  distance  of  two  or  three  hundred  feet.  In  some  cases,  as, 
for  example,  the  mouth  of  the  Harlem  river  and  those  bends  in  the  Lower  East  river 
known  as  Wallabout  bay  and  the  foot  of  Oliver  street,  Manhattan,  the  sewage  dis- 
colors many  acres  of  the  harbor. 


616        DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


Sludge  Deposits 

Most  of  the  deposits  which  exist  on  the  harbor  bottom  consist  of  colloid  and  other 
finely  divided  particles.  Accumulations  of  this  material  are  difficult  to  handle  except 
by  pumping.  When  dredged,  much  of  it  flows  back  into  the  water.  Sea  water  has  a 
tendency  to  precipitate  finely  divided  solid  matters,  and  large  areas  of  New  York  har- 
bor are  covered  with  deposits;  in  fact,  the  only  parts  of  the  harbor  which  are  not  con- 
taminated by  sewage  solids  are  those  wherein  the  tidal  currents  are  too  swift  to  permit 
deposits  of  any  kind  to  form. 

About  350,000  cubic  yards  of  material  are  dredged  from  the  waterways  around 
Manhattan  Island  by  the  Dock  Department  of  the  city  and  a  large  amount  of  addi- 
tional dredging  is  done  at  private  expense.  Unfortuntely,  the  deposition  of  sludge 
cannot  be  regulated  so  as  to  take  place  at  certain  points  from  which  they  may  be 
easily  dredged.  The  accumulations  which  occur  near  the  mouths  of  the  sewers  are 
being  continually  moved  from  place  to  place  by  the  changing  currents,  which  set  the 
semi-solid  sewage  particles  in  motion. 

Sewage  sludge  which  remains  for  a  time  upon  the  bottom  gradually  undergoes 
a  change  in  which  the  more  solid  materials  are  disintegrated  and  turned  into  liquid 
and  gaseous  compounds,  some  of  which  have  a  strong  avidity  for  oxygen.  It  is  after 
the  sewage  solids  have  been  deposited  upon  the  harbor  bottom  and  decomposition  has 
set  in  that  putrefactive  changes  become  most  pronounced,  and  the  most  offensive  odors 
are  given  off. 

The  Docks  as  Sewage  Traps. — The  more  quiet  parts  of  the  harbor,  and  especially 
the  spaces  between  the  long  docks,  are  of  much  interest  from  the  standpoint  of 
oxygen  exhaustion.  They  have  been  well  termed  "sewage  traps."  The  study  which 
anyone  can  make  of  them  from  the  surrounding  piers  and  bulkheads  will  make  it 
clear  why  the  slips  continually  require  to  be  dredged  in  order  that  a  proper  depth  of 
water  may  be  preserved  for  navigation ;  why  the  water  bubbles  with  offensive  gases ; 
why  the  dredged  material  is  so  foul  and  why  it  is  that  sewage  solids  accumulate 
between  the  piers  even  when  the  bottoms  of  the  main  tidal  currents  beyond  the 
pierhead  line  are  relatively  free  from  sewage  deposits.  Knowledge  of  these  local- 
ities, based  on  personal  inspection,  will  make  it  easy  to  understand  why  the  extension 
of  the  sewer  outfalls  in  Manhattan  from  the  bulkhead  lines  to  the  ends  of  the  docks 
has  not  produced  satisfactory  conditions,  and  why  something  more  is  needed  in  the 
way  of  protecting  the  water  than  would  be  afforded  by  passing  the  sewage  through 
screens  or  settling  basins  in  the  crowded  and  polluted  sections  of  the  Lower  East 
river. 


DIGESTION  OF  SEWAGE  AND  EXHAUSTION  OF  OXYGEN  617 

Precipitating  Action  of  the  Salt  Water. — Experiments  made  by  the  Commission 
show  that  sewage  deposits  take  place  more  rapidly  in  New  York  harbor  water  than 
in  the  water  of  inland  rivers  and  lakes.  Two  bottles,  alike  in  all  respects,  were  filled, 
in  one  case,  with  harbor  water  and,  in  the  other,  with  water  from  the  public  drink- 
ing water  supply.  An  equal  quantity  of  sewage  sludge  was  placed  in  each  bottle. 
The  bottles  were  thoroughly  shaken  and  allowed  to  stand  upon  a  table  to  permit  the 
deposit  to  settle  out.  At  the  end  of  half  an  hour  the  harbor  water  was  noticeably 
clearer  than  the  upland  water.  At  the  end  of  one  hour  the  difference  was  marked;  a 
heavy  deposit  had  settled  upon  the  bottom  of  the  harbor  water  and  there  was  little 
change  in  the  bottle  containing  the  upland  water.  At  the  end  of  three  hours  some 
deposit  was  visible  in  the  upland  water,  but  the  water  itself  was  not  as  clear  as  the 
harbor  has  been  at  the  end  of  the  first  half  hour.  As  nearly  as  could  be  estimated, 
the  harbor  water  deposited  its  suspended  matter  more  than  twelve  times  as  rapidly 
as  the  upland  water. 

Conditions  Necessary  fob  Final  Disposition 

Elsewhere  the  Commission  has  shown  that  the  final  decomposition  of  sewage  by 
natural  processes  requires  that  the  solids  shall  be  liquefied  and  the  liquids  oxidized. 
Nature  requires  that  all  organic  matters  be  resolved  into  stable  mineral  forms.  In 
this  final  condition,  all  substances  are  inoffensive  and  incapable  of  becoming  so. 

The  liquid  part  of  sewage  contains  about  one-half  of  the  total  organic  matter 
present,  and,  unlike  the  solid  material,  is  in  condition  for  immediate  oxidation.  The 
oil  and  grease  which  sewage  contains,  although  not  large  in  amount,  change  slowly 
in  composition,  but  their  effects,  when  discharged  into  the  harbor  waters,  are  con- 
spicuous. The  grease  floats  upon  the  surface  of  the  water,  at  times,  in  large  patches 
which  are  distinctly  visible  for  1,000  feet  or  more  from  the  mouths  of  the  principal 
sewer  outlets.    A  distinctly  greasy  odor  is  imparted  to  the  shores. 

The  chemical  changes,  and  particluarly  the  absorption  of  oxygen,  which  occur 
during  digestion  of  sewage  in  water  has  been  investigated  by  Adeney  and  made  the 
subject  of  an  exhaustive  report  to  the  Royal  Commission  on  Sewage  Disposal  of  Great 
Britain.*  The  work  of  this  investigator  was  based  on  the  well-known  researches  of 
Frankland,  which  showed  that  the  essential  cause  of  change  was  one  of  oxidation,  and 
those  of  Dupre',  who  proved  that  the  rate  of  oxidation  was  largely  due  to  bacteria. 

•  It  appears  that  the  digestion  of  sewage  matters  in  water  depends  not  alone  on 
the  exact  quantity  and  chemical  composition  of  the  sewage,  but  rather  upon  the  fer- 
mentative properties  of  the  mixture  of  sewage  and  water.   The  rate  at  which  sewage 

•See  Appendix  VI,  Fifth  Report  of  the  Royal  Commission  on  Sewage  Disposal,  1908. 


618        DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

matters  undergo  change  depends  largely  upon  the  influence  of  the  organisms  present. 
Adeney  was  convinced  that  the  purification  of  polluted  sea  water  was  chiefly  a  physio- 
logical process  analogous  to  the  respiratory  process  of  higher  vegetable  organisms, 
and  that  enzymic  action  was  intimately  associated  with  the  process. 

The  Two  Stages  in  the  Self -Purification  of  Sewage  Polluted  Water. — In  a  report 
made  by  Professor  Adeney  to  the  Metropolitan  Sewerage  Commission,*  an  explana- 
tion is  given  of  the  fermentative  processes  which  sewage  undergoes  through  the  action 
of  water  bacteria,  from  which  it  would  appear  that  decomposition  proceeds  in  two 
distinct  and  progressive  stages:  The  organic  matters  are  first  completely  fermented 
and  are  almost  entirely  oxidized  during  the  process;  the  products  are  water,  carbon 
and  ammonia.  Small  quantities  of  organic  substances  appear  as  excretory  bodies 
which  result  from  this  process,  and  these  possess  the  chemical  and  physical  prop- 
erties of  the  humus  of  cultivated  soils,  peated  rivers  and  lakes. 

When  the  fermentation  of  the  organic  constituents  has  been  completed  the  second 
stage  occurs  during  which  the  ammonia  compounds  and  humus  matters  formed  during 
the  first  process  are  oxidized  to  nitrites,  nitrates,  carbon  dioxide  and  water.  The 
terms  "carbon  fermentation"  and  "nitrogen  fermentation"  are  suggested  as  descriptive 
of  these  two  stages  of  sewage  fermentation  in  water,  and  the  following  classification 
of  the  bodies  which  may  occur  in  polluted  waters  is  recommended : 

1.  Carbon  fermentable  substances,  that  is,  nearly  all  existing  organic  substances 
other  than  antiseptics  which  have  not  to  be  subjected  to  the  fermentative  action  of 
water  bacteria. 

2.  Nitrogen  fermentable  organic  substances,  that  is,  organic  substances  which 
have  resulted  from  the  carbon  fermentation  of  other  organic  bodies. 

2a.  Ammonium  Compounds.  It  is  to  be  observed  that  the  oxidation  of  organic 
carbon  to  carbon  dioxide  constitutes  the  central  feature  of  the  first  stage,  and  that  the 
oxidation  of  ammoniacal  nitrogen  to  nitrous  and  nitric  acid  constitutes  the  central 
feature  of  the  second  stage. 

The  products  of  the  second  stage  are  the  analogues  of  the  product,  carbon  dioxide, 
of  the  first  stage.  The  sequence  of  these  changes  is  in  conformity  with  thermo  chem- 
ical principles,  and  an  exposition  of  the  scientific  basis  upon  which  this  view  of  the 
self-purification  of  polluted  waters  is  founded  is  contained  in  Section  1,  Appendix  6, 
Fifth  Report  of  the  Royal  Commission  on  Sewage  Disposal. 

According  to  Professor  Adeney's  reasoning,  the  most  important  effect  produced 
by  the  introduction  of  sewage  into  the  harbor  waters,  and  one  which  invariably  fol- 

*See  Report  of  Metropolitan  Sewerage  Commission,  August,  1912,  pp.  80-121. 


DIGESTION  OF  SEWAGE  AND  EXHAUSTION  OF  OXYGEN  619 

lows,  is  the  more  or  less  complete  exhaustion  of  their  dissolved  oxygen.    Three  dis- 
tinct causes  of  loss  are  to  be  noted : 

1.  The  sewage  being  deficient  in  oxygen  would,  by  mere  physical  pollution,  lower 
the  amount  of  dissolved  oxygen  in  any  mixture  of  sewage  and  clean  water  which  might 
be  made  with  it. 

2.  Where  sewage  contains  substances  which  should  easily,  directly  and  immedi- 
ately oxidize,  without  the  intervention  of  bacterial  or  enzymic  action. 

3.  The  organic  and  ammonium  compounds  of  sewage  when  acted  upon  by  fer- 
mentative processes  cause  a  loss  of  the  dissolved  oxygen.  Ordinarily  only  the  last  of 
these  three  actions  is  capable  of  producing  appreciable  influence  upon  the  dissolved 
oxygen  in  the  water. 

The  first  is  instantaneous  in  effect;  the  second  may  be  practically  instantaneous, 
as  where  sulphuretted  hydrogen  and  black  sulphite  of  iron,  both  of  which  are  among 
the  most  commonly  occurring  bodies  of  a  directly  oxidizable  character  found  in  sewage 
sludge,  especially  in  the  presence  of  sea  water,  are  oxidized  by  direct  contact  with  dis- 
solved oxygen  with  great  rapidity. 

The  effect  of  the  third  action  upon  the  dissolved  oxygen  is  distinctly  different 
since  it  proceeds  with  extreme  slowness,  and  occupies  several  days  under  natural  con- 
ditions. The  effects  which  the  sewage  sludge  matters  discharged  into  New  York  har- 
bor exert,  when  they  become  diffused  through  the  tidal  waters  after  having  been  de- 
posited in  the  form  of  sludge,  subjected  there  to  putrefactive  processes  in  the  presence 
of  sea  water,  and  finally  raised  by  gas,  eddies  or  other  means  and  diffused,  are  much 
more  injurious  than  those  which  the  same  solid  matters  can  cause  when  in  a  fresh 
condition.  The  explanation  of  this  fact  lies  in  the  large  quantities  of  sulphides  and 
other  immediately  oxidizable  compounds  which  are  produced  in  the  fermenting 
sludge. 

Liquid  sewage  matters  when  discharged  in  a  fresh  condition  are  not,  for  the  most 
part,  capable  of  direct  chemical  oxidation,  but  must  await  the  fermentative  action  of 
bacteria. 

AMOUNT  OF  OXYGEN  PRESENT  IN  UNPOLLUTED  WATERS 

The  quantity  of  dissolved  oxygen  which  is  present  in  unpolluted  water  under  or- 
dinary circumstances  is  relatively  small.  The  utmost  which  can  be  present,  termed 
the  saturation  value,  varies  according  to  the  salinity  of  the  water  and  the  tem- 
perature. 

Other  things  being  equal,  sea  water  contains  less  oxygen  than  water  that  is  not 
salt.    Harbor  water  containing  45  per  cent,  of  sea  water  holds,  at  45  degrees  F.,  7  c.c. 


620        DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

of  oxygen  per  liter  of  water.  When  the  temperature  reaches  75  degrees  the  oxygen 
is  expelled  to  the  atmospheric  air  until  about  5.5  c.c.  are  present.  During  the  summer 
months  the  water  may  become  so  warm,  particularly  in  those  parts  of  the  harbor  in 
which  a  free  circulation  does  not  occur,  as  to  reduce  the  normal  amount  of  oxygen  to 
about  5  c.c.  per  liter. 

The  physical  law  by  which  the  amount  of  oxygen  which  can  be  present  is  re- 
duced in  warm  weather  operates  against  the  disposal  of  New  York's  sewage  by  dilu- 
tion, since,  at  the  season  when  decomposition  is  most  active  and  oxygen  is  most  in 
demand,  the  supply  of  it  is  most  deficient. 

The  difference  in  the  amount  of  oxygen  which  may  be  present  in  sea  water  and 
upland  water  amounts  to  20  per  cent,  under  summer  conditions.  Thus,  at  70  degrees 
F.,  the  saturation  value  of  oxygen  is  5.2  c.c.  per  liter  in  sea  water  and  6.4  in  upland 
water.  The  table  on  page  52  and  the  diagram  on  page  51  of  the  Commission's  report 
of  August,  1912,  give  the  amount  of  oxygen  required  to  saturate  tidal  waters  contain- 
ing various  percentages  of  sea  water  and  mixtures  thereof  under  different  condi- 
tions of  temperature. 

Method  of  Stating  Results. — Throughout  the  work  of  the  Commission,  it  has  been 
customary  to  state  the  amount  of  oxygen  present  as  cubic  centimeters  of  oxygen  per 
liter  of  water  and  as  percentages  of  saturation  value.  This  custom  is  followed  by 
the  Royal  Commission  on  Sewage  Disposal  of  Great  Britain,  but  in  America  the 
results  are  stated  as  parts  of  oxygen  by  weight  per  million  parts  by  weight  of  water. 
The  Commission's  method  of  stating  the  results  can  be  converted  into  parts  per  mil- 
lion by  multiplying  the  number  of  cubic  centimeters  found  by  1.43.  The  diagram  on 
page  51  of  the  Commission's  report  of  August,  1912,  facilitates  this  conversion. 

Sources  op  the  Dissolved  Oxygen 

The  dissolved  oxygen  which  is  present  in  a  natural  body  of  water  is  assumed  to 
have  been  derived  from  the  atmosphere.  Numerous  analyses  of  the  Hudson  river, 
Long  Island  sound  and  ocean  beyond  the  limits  of  sewage  pollution  show  that  an 
amount  of  oxygen  is  present  which  compares  closely  with  the  theoretical  saturation 
value,  and  were  it  not  for  human  occupancy  the  water  of  New  York  harbor  would 
doubtless  contain  the  maximum  supply  which  the  temperature  and  salinity  of  the 
water  permit. 

There  are  various  sources  from  which  the  oxygen  which  is  exhausted  by  the  sew- 
age substances  is  in  part  replaced.  Among  these  sources  are  the  atmosphere,  the  fresh 
water  which  enters  the  harbor  from  the  ocean,  sound  and  rivers  and  the  oxygen  which 
exists  in  combined  form  in  the  mineral  matters  which  the  harbor  waters  contain. 


DIGESTION  OF  SEWAGE  AND  EXHAUSTION  OF  OXYGEN  621 

Absorption  of  Oxygen,  from  the  Air. — The  absorption  of  oxygen  from  the  atmos- 
phere has  been  the  subject  of  scientific  controversy,  Professor  Adeney  holding  views 
upon  this  subject  which  Professor  Phelps  and  Colonel  Black  have  attacked.  It  is  un- 
necessary here  to  enter  into  the  scientific  details,  many  of  which  can  be  found  in  Ap- 
pendix VI  of  the  Fifth  Report  of  the  Royal  Commission  on  Sewage  Disposal  of  Great 
Britain;  in  Professor  Adeney's  report  to  the  Commission,  published  in  the  Commis- 
sion's report  of  August,  1912;  in  the  report  of  Colonel  William  M.  Black  and  Pro- 
fessor Earle  B.  Phelps  to  the  Board  of  Estimate  and  Apportionment  of  New  York  in 
1911;  and  in  a  paper  and  discussion  opened  by  Professor  Phelps  in  the  Proceedings 
of  the  American  Society  of  Civil  Engineers  in  1913.  The  chief  point  at  issue  seems 
to  lie  in  the  interpretation  of  the  results  of  certain  delicate  experiments  which  the 
authors  have  made  to  determine  the  exact  way  in  which  the  oxygen  is  absorbed  by 
harbor  water  and  transmitted  from  the  surface  downward. 

Among  the  admitted  conditions  upon  which  absorption  of  oxygen  or,  as  it  is 
sometimes  called,  reaeration,  proceeds  are  the  area  of  water  exposed  to  the  air,  the 
temperature  of  the  water,  the  salinity  of  the  water,  the  humidity  of  the  atmosphere, 
the  amount  of  oxj'gen  which  the  water  already  contains,  the  depth  of  the  water,  the 
rate  at  which  the  oxygen  which  is  absorbed  at  the  surface  may  be  diffused  through- 
out the  body  of  the  water  and  the  presence  or  absence  of  vertical  currents. 

Owing  to  the  variation  which  occurs  in  all  of  these  factors  in  New  York  harbor, 
it  is  apparent  that  the  rate  at  which  oxygen  is  absorbed  from  the  air  varies  greatly 
from  day  to  day,  hour  to  hour  and  place  to  place.  The  area  of  the  water  surface 
changes  continually  under  the  influence  of  the  winds  which  produce  waves  and  some- 
times break  the  surface.  Decided  temperature  changes  occur  under  the  influence  of 
the  sun  and  inflowing  waters.  The  salinity  changes  with  each  tide  and  with  the 
rainfall.  The  humidity  of  the  atmosphere,  and,  consequently,  the  evaporation  from 
the  surface  of  the  water,  correspond  with  changes  in  the  weather.  The  amount  of 
oxygen  present  in  the  water  is  by  no  means  the  same  throughout  the  harbor,  nor 
does  it  remain  constant  in  any  place  which  is  under  the  immediate  influence  of  the 
sewage  and  the  tidal  currents.  The  depth  of  water  varies  as  the  currents  flow 
through  the  shallower  and  deeper  channels.  The  rate  of  diffusion  under  these  chang- 
ing conditions  cannot  be  expected  to  follow  any  fixed  law,  but,  if  it  does  so,  the  effects 
must  be  greatly  modified  by  the  lateral  and  vertical  currents  set  up  by  the  tide  and 
by  the  large  amount  of  traffic  in  the  harbor. 

The  rate  at  which  absorption  of  oxygen  can  take  place  under  any  circumstances 
is  relatively  slow.  In  the  year  1912,  the  Commission  made  a  series  of  experiments  on 
the  absorption  of  oxygen  by  water  and  the  results  obtained,  and  stated  elsewhere  in 


622        DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

this  report,  show  the  approximate  rate  at  which  oxygen  is  absorbed  by  water  from 
the  air.  In  these  experiments,  sea  water,  land  water  and  mixtures  of  the  two  were 
deprived  of  more  or  less  of  their  oxygen  by  boiling,  cooled  without  allowing  air  to 
come  in  contact  with  them  and  then  exposed  to  the  atmosphere  for  various  periods  of 
time,  the  dissolved  oxygen  being  determined  before  and  after  the  exposure. 

It  was  found  that  water  absolutely  or  nearly  free  from  oxygen,  if  exposed  to  the 
air  in  an  open  vessel,  such  as  a  wide-mouthed  bottle,  will,  without  any  agitation  of  the 
surface,  at  first  absorb  oxygen  rapidly  from  the  atmosphere,  the  rate  decreasing  as 
the  degree  of  saturation  increases  until,  as  the  saturation  figure  is  approached,  the 
process  of  absorption  goes  on  slowly.  In  the  experiments,  water  nearly  devoid  of 
oxygen  absorbed  over  50  per  cent,  of  the  saturation  value  of  oxygen  in  the  first  24 
hours,  the  rate  for  the  first  hour  being  10  per  cent,  of  the  total  quantity  necessary 
for  saturation.  The  rate  during  the  second  day  was  about  25  per  cent,  of  that  of  the 
first  day.  The  rate  then  decreased  gradually  during  the  third  and  fourth  days,  when 
there  was  a  marked  falling  off,  so  that  at  the  end  of  the  week,  as  the  saturation  value 
was  approached,  the  absorption  amounted  to  a  very  little  each  day. 

The  rate  for  sea  water  was  rather  more  rapid  than  for  land  water.  While  the 
land  water  absorbed  53  per  cent,  or  slightly  more  during  the  first  24  hours,  the  sea 
water  absorbed  60.  After  the  second  day,  the  rate  of  absorption  was  greater  in  the 
land  water  than  in  the  sea  water,  an  observation  which  is  doubtless  to  be  accounted 
for  by  the  fact  that  the  sea  water  was  more  nearly  approaching  its  saturation  value. 

In  no  case  was  the  water  found  to  be  saturated  at  the  end  of  seven  days,  although 
it  closely  approached  that  condition.  It  took  ten  days  in  some  cases  before  the  land 
and  sea  waters  became  fully  saturated. 

The  gain  during  the  first  hour  of  exposure  was  about  the  same  with  land  water  as 
with  sea  water.  At  the  end  of  the  2d,  3d,  4th,  5th,  6th,  7th,  8th  and  24th  hours,  the 
absorption  of  oxygen  was  found  to  be  greater  with  the  sea  water  than  with  the  land 
water,  the  total  gain  for  the  first  day  with  the  sea  water  being  about  8  per  cent, 
greater. 

In  mixtures  of  sea  water  and  land  water  possessing  from  14  to  45  per  cent,  of 
oxygen,  the  gain  per  hour  varied  between  10  and  4  per  cent.  If  these  facts  are  appli- 
cable to  New  York  harbor,  it  would  appear  that  the  absorption  of  oxygen  from  the 
atmosphere  under  conditions  such  as  are  likely  to  occur  in  the  summer  weather  is 
equivalent  to  about  7  per  cent,  of  the  saturation  value  per  hour.  The  conditions, 
however,  under  which  the  oxygen  can  be  absorbed  by  the  harbor  waters  are  too  numer- 
ous to  make  deductions  of  this  kind  entirely  safe. 


DIGESTION  OF  SEWAGE  AND  EXHAUSTION  OF  OXYGEN  623 

Fresh  Sea  Water  and  Upland  Water  as  Sources  of  Oxygen. — In  the  opinion  of 
many  persons,  direct  absorption  from  the  atmosphere  plays  but  a  small  part  in  supply- 
ing the  oxygen  required  by  the  harbor  for  the  digestion  of  the  sewage.  The  principal 
supply  is  furnished  by  the  fresh  sea  water  and  relatively  unpolluted  river  water  which 
enter  the  harbor. 

Calculations  have  been  made  of  the  extent  to  which  the  water  of  the  sea  and  rivers 
renews  the  water  of  the  harbor,  the  object  of  these  calculations  being  to  determine 
the  extent  to  which  the  sewage  matters  are  carried  mechanically  to  sea.  So  far  as  the 
ocean  water  is  concerned,  the  basis  of  these  studies  has  been  the  estimates  of  the 
United  States  Coast  and  Geodetic  Survey  made  in  1908  at  the  request  of  the  Metro- 
politan Sewerage  Commission ;  the  Commission's  studies  of  the  changing  salinity 
of  the  water  carried  on  throughout  one  year  at  11  widely  separated  stations  in  the 
harbor;  the  float  observations  and  the  thousands  of  analyses  made  in  the  Commis- 
sion's laboratories.  The  supply  of  water  from  the  rivers  has  been  calculated  from 
runoff  data  supplied  by  the  New  York  State  Engineer.  Mathematical  discussions  of 
the  transportation  of  the  sewage  to  sea  have  been  made  by  Professor  Adeney, 
Messrs.  Black  and  Phelps  and  others  without,  however,  affording  convincing  evidence 
of  the  practical  application  of  the  results.  The  inward  and  outward  flow  of  sea 
water,  like  the  discharge  of  water  from  the  rivers,  does  not  produce  the  immediate 
and  thorough  diffusion  throughout  the  harbor  waters  which  such  calculations  assume. 

Oxygen  Supplied  by  Mineral  Compounds. — In  most  waters  a  considerable  amount 
of  oxygen  is  present  in  the  form  of  mineral  compounds,  as,  for  example,  carbonates, 
sulphates,  nitrates  and  nitrites.  These  compounds  are  relatively  stable  and  some  of 
them  may  be  regarded  as  the  end  products  of  those  changes  which  organic  matters 
undergo  in  the  process  of  decomposition  in  the  presence  of  oxygen.  This  is  partic- 
ularly true  of  nitrates.  Nitrates  are  always  abundant  in  waters  which  have  been  pol- 
luted and  in  which  digestion  has  passed  to  its  final  and  inoffensive  state. 

Carbonates  indicate  a  water  possessing  temporary  hardness  and  are  usually 
taken  as  showing  the  solution  of  rocks  containing  lime  and  magnesia  in  the  presence 
of  carbonic  acid,  presumably  derived  from  the  decomposition  of  vegetable  matter  as  in 
swamps. 

Sulphates  indicate  a  permanently  hard  water,  that  is  one  whose  soap-consuming 
and  boiler-scale-forming  properties  are  not  reduced  by  boiling.  Sea  water  contains  a 
great  deal  of  sulphate,  a  considerable  amount  of  carbonate  and  very  little  nitrate. 

When  sewage  matters  putrefy  in  the  presence  of  sea  water,  the  oxygen  present  in 
the  form  of  mineral  compounds  is  attacked,  the  result  being  a  reduction  in  the  nitrates 
and  sulphates  if  not  in  the  carbonates  present.    The  Commission  has  found  that 


624        DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

nitrates  are  reduced  before  the  dissolved  oxygen  is  entirely  gone  from  the  water  and 
putrefaction  commences.  There  is  thus  little,  if  any,  oxygen  to  be  depended  upon  from 
nitrates  after  the  dissolved  oxygen  is  gone. 

The  sulphates  do  not  readily  part  with  their  oxygen.  They  are  among  the  most 
resistant  of  chemical  substances  and  are  broken  down  only  in  the  presence  of  active 
putrefactive  decomposition,  so  far  as  sewage  is  concerned. 

Analysis  of  the  gases  evolved  from  New  York  harbor  shows  very  little  sulphur- 
etted hydrogen  and  a  great  deal  of  marsh  gas  and  other  compounds  from  which 
sulphur  is  absent. 

It  is  doubtful  whether  the  carbonates  in  harbor  water  are  capable  of  affording 
any  useful  amount  of  oxygen  in  the  mineralization  of  the  sewage  matters.  Putrefaction 
produces  carbonic  acid,  much  of  which  goes  into  solution  in  the  water  and  some  of 
which  is  evolved  in  bubbles  at  the  surface. 

A  brief  consideration  of  the  changes  which  take  place  in  the  nitrogen  compounds 
will  serve  to  indicate,  in  a  general  way,  how  the  oxygen  may  be  combined  with  the 
elements  of  the  sewage  as  a  result  of  digestion  and  how  it  may  be  disrupted  from  such 
combination. 

Nitrogenous  matter,  in  the  least  digested  form  in  which  it  is  customarily  deter- 
mined in  sewage  and  water  analysis,  is  reckoned  as  albuminoid  ammonia.  In  this  con- 
dition it  is  not  ammonia,  but  is  assumed  to  be  in  an  albuminous  condition  which  is 
capable  of  being  converted  into  ammonia  in  nature  by  biological  action  or  in  the 
laboratory  by  means  of  strongly  alkaline  permanganate  of  potash.  Theoretically,  the 
nitrogen  of  albuminoid  ammonia  will,  in  course  of  time,  become  free  ammonia  and 
then  pass  to  nitrites  and  nitrates.  In  the  changes  which  result  in  free  ammonia, 
oxygen  is  not  known  to  play  any  part. 

Once  the  nitrogen  has  reached  the  stage  of  ammonia,  the  presence  of  oxygen  be- 
comes an  important  factor.  The  nitrogen  and  hydrogen  atoms,  of  which  ammonia  is 
composed,  unite  with  oxygen  and  form  nitrites  which,  by  further  oxidation,  are  con- 
verted to  nitrates.  The  presence  of  nitrites  in  water  is  regarded  as  indicating  the  rate 
at  which  the  digestive  process  is  proceeding.  Nitrites,  when  abundant,  are  generally 
accepted  as  indicating  recent  heavy  pollution.  Nitrates,  when  high,  are  taken  to 
signify  tbat  the  water  has  passed  through  a  change  which  has  resulted  in  the  oxida- 
tion or  mineralization  of  such  harmful  and  offensive  matters  as  may  have  been  pres- 
ent. The  proportion  in  which  these  various  compounds,  ranging  from  albuminoid 
ammonia  to  nitrates,  are  present  in  a  water  gives  to  the  sanitary  analyst  a  knowledge 
of  the  recentness  and  extent  of  the  pollution  of  the  water. 


DIGESTION  OF  SEWAGE  AND  EXHAUSTION  OF  OXYGEN  625 

It  has  often  been  remarked  that  sea  water  contains  but  little  nitrates,  their 
presence  having  been  questioned  by  some.  The  Commission  has  shown  that  sea  water 
contains  nitrates.  In  view  of  the  enormous  extent  to  which  organic  matter  is  diluted 
in  sea  water,  it  does  not  seem  remarkable  that  only  small  quantities  are  discoverable. 

Nitrites  are  present  to  an  unusual  extent  in  the  water  of  New  York  harbor. 
Their  presence  well  illustrates  the  digestive  changes  which  are  taking  place.  When 
considered  in  the  light  of  other  data  relating  to  the  quality  of  the  water,  there  is 
little  about  their  presence  to  cause  remark. 

In  order  that  the  Commission's  investigations  should  have  a  broad  foundation 
and  not  rest  exclusively  upon  the  extensive  dissolved  oxygen  analysis  which  were 
made,  a  considerable  number  of  analyses  for  the  nitrogen  compounds  were  carried  out 
and  the  results  will  be  found  in  appropriate  places  in  the  tables. 

The  circumstances  and  extent  to  which  the  oxygen  which  is  present  in  the  form 
of  mineral  compounds  can  be  turned  to  the  most  useful  account  in  the  digestion  of  the 
sewage  matters  depend  upon  many  factors  which  have  nowhere,  as  yet,  received 
thorough  investigation.  The  discovery  of  the  controlling  factors  in  the  problem  will 
doubtless  remain  a  field  of  research  for  many  years  to  come.  It  now  appears  that 
before  this  combined  oxygen  can  be  liberated  and  made  available  for  the  digestive 
processes,  putrefaction,  or  an  approach  t<>  it,  must  intervene. 

Attention  has  recently  been  attracted  to  the  instrumentality  of  plankton  in 
breaking  up  the  completely  or  partly  oxidized  mineral  compounds  present  in  polluted 
water  and  thus  adding  to  the  dissolved  oxygen  content.  The  theory  upon  which  the 
action  of  the  plankton  depends  is  the  same  as  that  which  seeks  to  explain  one  of  the 
most  important  of  those  facts  relating  to  the  inter-relation  of  animals  and  plants. 
In  the  respiratory  action  of  animals,  oxygen  is  absorbed  and  carbonic  acid  is  evolved, 
and  the  corresponding  function  of  plants  is  to  appropriate  the  carbon  and  liberate  the 
oxygen  of  carbonic  acid. 

However  complete  the  action  by  which  the  oxygen  that  may  be  present  in  mineral 
combinations  is  liberated,  it  is  evident  that  it  can  bring  about  nothing  more  than  an 
exchange.  No  oxygen  is  produced.  Nevertheless,  the  effect  upon  the  digestive  process 
may  be  excellent.  It  may  facilitate  decomposition,  for  the  oxygen,  when  disassociated 
from  the  other  elements  with  which  it  is  combined,  is  present  in  a  nascent  form  and  in 
this  state  it  undoubtedly  has  a  strong  avidity  to  form  combinations. 

Elsewhere  in  this  report  will  be  found  the  results  of  experiments  on  the  disap- 
pearance of  nitrates  in  water  concurrently  with  the  absorption  of  dissolved  oxygen. 
The  experiments  show  that  the  oxygen  in  the  form  of  nitrates  may  be  absorbed,  to 
some  extent  at  least,  long  before  the  dissolved  oxygen  disappears. 


626         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

There  is  another  source  of  oxygen  which,  although  probably  never  available,  is 
nevertheless  of  much  interest  in  considering  the  digestion  of  sewage.  This  source  is 
no  other  than  the  oxygen  of  which  the  water  itself  is  composed.  If,  in  the  digestion  of 
sewage,  the  molecules  of  water  which  are  composed  of  two  atoms  of  hydrogen  to  one 
of  oxygen  become  disrupted  and  the  oxygen  set  free,  the  digestive  capacity  of  a  river 
or  harbor  would  obviously  become  enormously  increased.  In  the  existing  state  of 
knowledge,  there  is  no  reason  to  suppose  that  the  oxygen  of  which  water  is  composed  is 
ever  made  available  for  the  mineralization  of  organic  or  nitrogenous  matter. 

Oxygen  as  a  Measure  of  Pollution 

In  the  Commission's  opinion  the  amount  of  dissolved  oxygen  which  is  present  in 
a  natural  body  of  water  affords  the  best  means  available  for  measuring  the  burden  of 
pollution  which  has  been  put  upon  the  water  and  gives  a  basis  upon  which  to  form 
an  opinion  as  to  the  maximum  quantity  of  sewage  which  the  water  can  properly 
absorb.  So  far  as  future  conditions  are  concerned,  the  test  has  reference  chiefly  to 
the  possibility  that  the  sewage  materials  in  the  water  may  putrefy  and  produce  of- 
fensive odors.  If  there  is  much  oxygen,  this  probability  is  remote ;  if  there  is  but  little, 
the  danger  is  imminent.  Putrefaction  cannot  take  place  in  the  presence  of  an  abun- 
dant supply  of  oxygen. 

The  scientific  value  of  the  analysis  depends  on  the  fact  that  the  oxygen  which  is 
normally  present  in  the  water  is  used  up  by  the  processes  of  nature  in  changing  the 
decomposable  substances  of  the  sewage  into  harmless  and  inoffensive  compounds. 
This  change  has  been  termed  digestion.  It  is  a  complicated  process  and  one  which 
depends  upon  a  large  number  of  factors,  including  the  amount  and  condition  of  the 
organic  matter  in  the  sewage  and  in  the  water;  the  amount  of  dissolved  oxygen 
present  in  the  mixture;  the  temperature  of  the  water  and  the  presence  of  various 
substances  which  may  exert  a  beneficial  or  injurious  effect  upon  the  digestive  process. 

The  water  itself  plays  but  an  indifferent  part  in  the  digestive  process.  It  acts 
in  a  mechanical  way  to  separate  the  particles  to  be  digested  and  so  permits  the  active 
agencies  of  decomposition  to  come  freely  into  contact  with  the  substances  upon 
which  they  must  operate  without  undue  interference  from  the  harmful  products  of 
their  activity.  The  active  agencies  which  carry  on  the  process  of  digestion  include  a 
wide  range  of  animal  and  plant  forms,  among  which  the  bacteria  are  prominent. 
The  water  may  be  likened  to  a  laboratory  in  which  the  forces  of  nature  attack  and 
render  the  great  variety  of  waste  substances  inert.  When  these  wastes  are  too  con- 
centrated, that  is,  when  they  are  not  diluted  with  a  sufficient  supply  of  clean  water, 
they  pass  through  undesirable  and  offensive  changes. 


DIGESTION  OP  SEWAGE  AND  EXHAUSTION  OF  OXYGEN  627 

A  question  of  much  practical  significance  in  the  disposal  of  sewage  through  dilu- 
tion is  whether  putrefaction  has  any  effect  upon  the  total  quantity  of  oxygen  which 
a  given  volume  of  sewage  requires.  It  would  seem  that  the  laws  of  chemistry  demand 
that  a  given  amount  of  nitrogenous  and  organic  matter  require  a  definite  quantity  of 
oxygen  for  its  final  mineralization  irrespective  of  any  changes  through  which  the 
materials  requiring  oxidation  may  pass.  A  consideration  of  those  changes,  however 
incomplete  and  imperfect  as  the  existing  knowledge  of  them  is,  shows  that  putrefac- 
tion may  lead  to  a  reduction  in  the  quantity  of  oxygen  needed.  Putrefaction  pro- 
duces gases  and  with  these  gases  there  are  driven  into  the  atmosphere  oxygen-demand- 
ing elements,  notably  carbon  and  hydrogen,  which  lessen,  by  their  weight,  the  weight 
of  oxygen  which  the  water  must  supply. 

Proof  of  the  correctness  of  this  theory  has  not  been  afforded  by  laboratory  re- 
search, but  a  strong  presumption  in  its  favor  is  supplied  by  the  composition  of  the 
gases  and  by  the  fact  that  most  of  the  gases  are  inflammable.  Viewed  in  this  light, 
putrefaction  may  be  regarded  as  the  natural  provision  by  which  the  oxygen  require- 
ments of  decomposable  organic  and  nitrogenous  bodies,  whether  of  sewage  or  other 
origin,  may  be  lessened  in  natural  bodies  of  water  to  a  point  which  can  properly  be 
satisfied  by  the  oxygen  present. 

The  term  organic  matter  is  generally  applied  rather  loosely  to  indicate  the  de- 
composable materials  in  water  which  require  oxygen  for  their  resolution  into  inert 
mineral  compounds,  whether  these  materials  are  of  sewage  origin  or  are  derived  from 
natural  sources.  It  constitutes  those  chemical  elements  which  are  capable  of  putre- 
faction when  decomposed  in  the  absence  of  oxygen  and  those  which  abstract  oxygen 
when  decomposition  proceeds  under  ordinary  aerobic  conditions. 

From  a  chemical  standpoint,  organic  matter  is  not  necessarily  of  animal  or 
vegetable  origin.  It  can  be  produced  synthetically,  as  urea  and  asparagin,  for  ex- 
ample. Organic  chemistry  is  the  chemistry  of  the  carbon  compounds  and  from  a 
scientific  standpoint  it  is  proper  to  include  as  organic  matter  all,  and  only,  those  sub- 
stances which  include  carbon  atoms.  If  this  definition  is  employed,  there  will  remain 
outside,  and  in  addition  to  those  substances  commonly  called  organic  matters,  an  im- 
portant class  of  compounds  derivable  from  sewage  which  demand  oxygen  for  their 
mineralization.  These  include  ammonia  and  nitrites.  In  the  reports  of  this  Commis- 
sion, the  term  organic  matter  is  used  in  its  usual  and  popular  sense  to  include  all 
sewage  substances,  which  abstract  oxygen  from  the  water.  In  this  way  it  is  hoped 
that  much  confusion  will  be  avoided. 


628         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

Dissolved  oxygen  figures  are  not  capable  of  giving  a  knowledge  of  tbe  existence 
of  fresb  sewage  odors.  Sucb  odors  are  often  present  wben  large  quantities  of  sewage 
are  discharged  into  natural  bodies  of  water  and  before  decomposition,  either  of  the 
offensive  or  inoffensive  kind,  has  set  in.  They  are  due  largely  to  air  entrained  in  the 
sewers  which  escapes  after  the  sewage  is  discharged.  Fields  of  sewage  which  lie  on 
the  surface  of  the  harbor  water  about  the  sewer  outfalls  generally  give  off  sweetish, 
greasy  odors  which  are  offensive  and  which  bear  no  relation  to  the  amount  of  dis- 
solved oxygen  which  the  water  contains.  Nor  are  these  odors  always  confined  to  the 
immediate  vicinity  of  sewer  outfalls.  The  well-mixed  water  in  the  center  of  the 
Lower  East  river  has  often  been  observed  to  give  them  off.  The  smell  is  particularly 
noticeable  in  the  wake  of  steamboats  whose  propellers  were  churning  up  the  waters 
and  sending  a  fine  spray  into  the  air.  The  amount  of  dissolved  oxygen  bears  no  known 
relation  to  the  existence  of  the  odors  of  fresh  sewage  produced  in  such  cases. 

The  most  important  case  in  which  the  oxygen  figures  fail  to  indicate  the  exist- 
ence or  probability  of  odor  is  where  relatively  clean  water  flows  over  the  top  of 
sludge  deposits.  This  is  the  most  usual  cause  of  the  offensive  odors  which  rise  from 
sewage  pollution.  Sludge  is  concentrated  sewage  and  when  it  becomes  stagnant  the 
oxygen  is  soon  exhausted  from  it,  putrefaction  sets  in  and  foul-smelling  gas  is  evolved. 
The  gas  escapes  sometimes  in  very  large  bubbles  which  rise  through  the  overlying  water 
and  escape  at  the  surface,  its  transit  being  relatively  short.  The  gas  has  a  strong 
avidity  for  oxygen  and  it  may  or  may  not  materially  affect  the  dissolved  oxygen  in  the 
water  through  which  it  passes,  according  to  the  amount  of  gas,  the  depth  of  water 
through  which  it  rises,  the  temperature  and  other  conditions. 

Insufficiency  of  Oxygen  as  a  Criterion  of  Pollution 

There  are  some  cases  in  which  the  dissolved  oxygen  figure  does  not  afford  a 
reliable  index  either  of  the  existing  pollution  or  the  probability  of  future  nuisance. 
For  example,  when  the  pollution  is  recent,  a  wrong  inference  may  be  drawn  for  there 
may  be  an  abundant  supply  of  oxygen  present  merely  because  sufficient  time  has  not 
elapsed  to  permit  the  decomposable  materials  of  the  sewage  to  cause  a  serious  drain 
upon  the  oxygen  in  the  water.  If  such  samples  are  kept  for  a  time,  a  further  deple- 
tion of  oxygen  will  occur,  and  the  extent  of  this  change,  if  properly  interpreted,  will 
give  information  which  is  often  of  great  value. 

Dissolved  oxygen  should  not  be  considered  apart  from  temperature  for  tempera- 
ture plays  an  important  part  in  the  rate  at  which  digestion  proceeds,  heat  favoring 


DIGESTION  OP  SEWAGE  AND  EXHAUSTION  OF  OXYGEN  629 

and  cold  retarding  the  process.  It  follows  from  this  that,  other  things  being  equal, 
more  sewage  can  be  discharged  into  cold  water  than  into  warm  water  without  danger 
that  putrefactive  changes  will  occur.  The  total  amount  of  oxygen  required  to  miner- 
alize organic  matters  is  doubtless  the  same  in  each  case,  but,  where  the  water  is  cold, 
decomposition  may  be  delayed  until  the  sewage  matters  have  been  carried  so  far  and 
been  diluted  so  greatly  as  to  preclude  the  possibility  of  nuisance  from  putrefaction. 

Where  the  summer  temperatures  are  high,  the  digestive  process  may  conceivably 
be  so  greatly  accelerated  that  practically  all  the  decomposition  which  is  possible  may 
take  place  at  the  point  at  which  the  sewage  is  discharged.  The  oxygen  is  consumed 
more  rapidly  than  it  can  be  furnished  from  the  supply  originally  contained  in  the 
water  or  by  absorption  from  the  atmosphere. 

Temperature  has  as  great  an  effect  upon  the  digestion  of  sludge  as  upon  the  ex- 
haustion of  oxygen  in  water,  although  sludge  is  always  devoid  of  oxygen.  There  seems 
to  be  no  exception  to  the  fact  that  the  warmest  temperatures  of  summer  facilitate 
both  the  offensive  and  inoffensive  forms  of  decomposition.  It  is  worth  knowing  in 
this  connection  that  the  range  in  temperature  which  marks  the  changes  of  season  in 
New  York  is  not  so  great  in  the  water  as  in  the  air,  and  is  much  less  in  the  sludge  at 
the  harbor  bottom  than  in  the  water  which  overlies  it. 

Evolutions  of  gas  take  place  throughout  the  year,  although  they  are  particularly 
active  in  the  summer  and  early  autumn  months. 

Extent  to  Which  the  Digestive  Capacity  May  Be  Utilized 

Proper  limits  to  the  extent  to  which  the  digestive  capacity  of  the  water  can  be 
utilized  for  the  disposal  of  sewage  should  rest  upon  the  digestive  capacity  of  the  water, 
aided  perhaps,  in  some  cases,  by  such  procedures  as  dredging.  There  are  many  objec- 
tions to  dredging  as  a  means  of  reinforcing  the  digestive  capacity  of  water  for  sewage, 
and  in  a  harbor  like  New  York,  where  deposits  of  sludge  are  likely  to  form  in  incon- 
venient situations  and  where  they  produce  nuisance  from  the  beginning  of  their  for- 
mation and  through  their  removal  by  dredges,  this  kind  of  assistance  may  well  be 
disregarded. 

In  the  opinion  of  the  Commission,  the  discharge  of  sewage  into  New  York  harbor 
should  be  so  regulated  and  controlled  as  not  unduly  to  exhaust  the  dissolved  oxygen  in 
the  water,  leading  to  the  formation  of  sludge  deposits  which  will  cause  offense  or  in- 
terfere with  the  interests  of  navigation  or  produce  a  considerable  injury  to  the  public 
health. 

It  will  be  proper  to  utilize  the  digestive  capacity  of  the  water  within  proper 
limits,  and  provided  suitable  restrictions  are  imposed,  such  as  have  just  been  men- 


630         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

tioned  and  are  more  adequately  dealt  with  in  the  Commission's  standard  of  cleanness 
for  the  waters,  no  material  harm  will  result. 

The  digestive  capacity  of  the  harbor  is  an  asset  of  great  value,  permitting  large 
savings  to  be  made  in  the  cost  of  the  main  drainage  and  disposal  works  which  the  City 
must  build  for  the  reasonable  protection  of  its  water  highways. 

It  is  impossible  by  means  of  oxygen  analyses  or  otherwise  to  determine  exactly  the 
digestive  capacity  of  New  York  harbor.  Too  many  factors  enter  into  the  problem  to 
permit  of  a  solution  so  easily  made.  The  area  is  great  and  the  conditions  various.  In 
some  respects  the  problem  has  to  be  studied  as  a  whole  and  in  others  it  must  be  resolved 
into  its  component  parts  for  investigation.  The  volumes  of  sewage  produced  and  the 
volumes  of  water  available  for  its  assimilation  differ  considerably  in  different  local- 
ities. The  necessity  for  any  given  degree  of  cleanness  is  not  the  same  everywhere. 
The  problem  is  complicated  by  the  oscillating  movement  of  the  tide.  The  measure  of 
the  digestive  capacity  of  inland  rivers,  known  as  the  dilution  method,  customarily 
used  by  engineers,  does  not  apply  to  New  York  harbor,  where  the  movement  of  the 
tide  makes  it  impossible  to  estimate  with  any  reasonable  degree  of  accuracy  how  much 
water  is  available  for  purposes  of  diluting  the  sewage. 

The  digestion  of  sewage  by  water,  as  relates  to  New  York,  has  been  carefully 
studied  by  the  Metropolitan  Sewerage  Commission  and  discussed  in  a  report  issued  in 
August,  1912.  The  report  is  accompanied  by  the  reports  of  eight  sanitary  experts  who 
were  called  upon  to  investigate  the  situation  independently  of  one  another  and  express 
an  opinion  as  to  the  restrictions  and  safeguards  which  should  control  the  discharge  of 
sewage  into  New  York  harbor.   A  summary  of  the  requirements  follows : 

1.  Garbage,  offal  or  solid  matter  recognizable  as  of  sewage  origin  shall  not  be 
visible  in  any  of  the  harbor  waters. 

2.  Marked  discoloration  or  turbidity,  effervescence,  oily  sleek,  odor  or  deposits, 
due  to  sewage  or  trade  wastes,  shall  not  occur  except  perhaps  in  the  immediate 
vicinity  of  sewer  outfalls,  and  then  only  to  such  an  extent  and  in  such  places  as  may  be 
permitted  by  the  authority  having  jurisdiction  over  the  sanitary  condition  of  the  harbor. 

3.  The  discharge  of  sewage  shall  not  materially  contribute  to  the  formation  of 
deposits  injurious  to  navigation. 

4.  Except  in  the  immediate  vicinity  of  docks  and  piers  and  sewer  outfalls,  the 
dissolved  oxygen  in  the  water  shall  not  fall  below  3.0  cubic  centimeters  per  liter  of 
water.*  Near  docks  and  piers  there  should  always  be  sufficient  oxygen  in  the  water 
to  prevent  nuisance  from  odors.f 

*With  60  per  cent,  of  sea  water  and  40  per  cent,  of  land  water  and  at  the  extreme  summer  temperature  of  80 
degrees  F.,  3.0  cubic  centimeters  of  oxygen  per  liter  corresponds  to  58  per  cent,  of  saturation. 

fFor  modification  of  Standard  of  Cleanness  as  regards  oxygen  content,  see  Part  III,  Chap.  I,  pages  154  and  218. 


DIGESTION  OF  SEWAGE  AND  EXHAUSTION  OF  OXYGEN  631 

5.  The  quality  of  the  water  at  points  suitable  for  bathing  and  oyster  culture 
should  conform  substantially  as  to  bacterial  purity  to  a  drinking  water  standard.  It 
is  not  practicable  to  maintain  so  high  a  standard  in  any  part  of  the  harbor  north  of 
the  Narrows,  or  in  the  Arthur  Kill. 

CALCULATION  OF  DILUTION  REQUIRED 
Dilution  Required 

As  a  result  of  observation  and  experiment  in  various  parts  of  the  world,  en- 
gineers have  formed  opinions  as  to  the  amount  of  sewage  which  can  safely  be  dis- 
charged into  a  natural  body  of  water,  such  as  an  inland  river  or  lake.  The  word 
safely  here  refers  solely  to  the  chance  of  producing  a  nuisance,  chiefly  odor.  It  has 
no  relation  to  the  effect  which  the  sewage  may  have  upon  health. 

According  to  the  opinion  of  American  engineers,  the  dilution  must  be  in  the 
proportion  of  at  least  20  or  25  parts  of  water  to  one  part  of  ordinary  sewage  and 
there  may  be  conditions  where  a  nuisance  may  result  where  the  dilution  amounts  to 
nearly  50  parts  of  water  to  one  part  of  sewage.  When  the  proportion  of  sewage  to 
water  is  greater  than  this,  the  capacity  of  the  water  is  likely  to  be  overtaxed.  These 
supposedly  safe  ratios  of  dilution  are  based  upon  the  assumption  that  the  water  with 
which  the  sewage  is  mixed  is  clean  and  possesses  its  normal  amount  of  oxygen.  Where 
the  water  is  polluted  to  begin  with  the  necessary  dilution  must  be  much  greater. 

In  the  Eighth  Report  of  the  Royal  Commission  on  Sewage  Disposal  of  Great 
Britain,  issued  at  the  end  of  1912,  it  is  recommended  that  where  the  dilution  of  sewage 
to  water  is  between  150  and  200  times,  the  sewage  should  be  purified  so  that  the 
effluent  will  not  contain  more  than  60  parts  of  suspended  matter  per  million  and  that 
only  when  the  dilution  exceeds  500  times  the  volume  of  sewage  should  crude  sewage 
be  permitted  to  be  discharged  into  a  water  course.  These  figures  refer  to  English 
sewage,  which  is  about  6  times  as  concentrated  as  American  sewage,  and  to  the  water 
of  inland  rivers  and  lakes,  but  the  Royal  Commission  holds  the  opinion  that  the  pro- 
portions hold  generally  true  for  tidal  waters  also. 

It  is  worthy  of  note  that  the  observations  upon  which  American  and  English 
experts  base  their  opinions  have  been  made  where  sewage  has  been  discharged  into 
inland  bodies  of  water.  There  has  been  no  study  of  the  discharge  of  sewage  into  tidal 
estuaries  which  would  permit  of  safe  ratios  to  be  stated  with  positiveness  for  salt 
water.   Such  investigations  as  have  been  made  indicate  that  sewage  solids  settle  more 


632         DATA  RELATING  TO  THE  PROTECTION  OP  THE  HARBOR 

rapidly  in  salt  water  than  in  land  water,  and  it  is  believed  that  gallon  for  gallon,  land 
water  will  dispose,  in  a  normal  manner,  of  more  sewage  than  sea  water. 

It  is  not  always  clear  how  the  dilution  of  sewage  can  be  calculated  in  sea  water. 
The  same,  or  nearly  the  same,  water  often  flows  backward  and  forward  for  days  near 
a  sewer  outfall,  while  the  discharge  of  sewage  is  continuous.  Under  these  circum- 
stances the  sewage  flow  is  irregular  and  its  calculation  is  involved  in  uncertainty. 

Errors  which  may  be  made  in  such  calculations  include  the  assumption  that: 

(a)  The  flow  of  sewage  is  uniform  during  the  24  hours.  It  may  vary  as  much  as 
50  per  cent,  at  different  hours. 

(b)  The  flow  of  tidal  water  is  uniform.  It  is  quite  the  reverse.  Aside  from  the 
fact  that  the  currents  at  each  turn  must  gradually  slow  down  to  the  stopping  point 
and  then  gradually  increase  to  the  normal  strength  of  flow,  winds,  heavy  rain,  snow 
and  intense  cold  may  each  produce  a  decided  effect  upon  the  volume  of  water  moving 
in  a  harbor. 

(c)  The  sewage  matters  become  immediately  and  thoroughly  mixed  with  the 
waters.  The  opposite  is  the  fact.  Dispersion  and  diffusion  are  difficult  to  accom- 
plish and  consequently  there  are  many  kinds  and  degrees  of  stagnation. 

(d)  The  sewage  remains  sewage  after  it  is  well  mingled  with  the  water.  This  is 
not  true.    Chemical  changes  at  once  set  in. 

(c)  The  waters  into  which  the  sewage  is  discharged  are  free  from  pollution  to 
begin  with.  This  assumption,  however  warranted  in  dealing  with  an  inland  river,  is 
quite  contrary  to  the  fact  as  related  to  New  York  harbor. 

The  changes  which  sewage  undergoes  when  it  is  discharged  into  a  natural  body 
of  water  should  be  carefully  kept  in  mind,  and  the  mistake,  often  made,  of  assuming 
that  the  sewage  remains  and  can  be  reckoned  with  as  sewage  after  admixture  should 
be  avoided.  In  no  other  way  is  it  possible  to  obtain  an  accurate  understanding  of 
the  subject.  It  is  wrong  to  speak  of  sewage  matters  as  sewage  two  or  three  hours  after 
they  have  been  discharged  into  a  tidal  estuary.  Some  of  the  original  ingredients 
may  still  exist,  but  the  chances  are  all  against  the  continuance  of  any  of  them  in  an 
unaltered  condition  except  the  grosser  solids  and  such  others  as  may  be  able  to  per- 
sist in  greatly  diluted  form. 

Oxygen  Required 

It  is  impossible  to  say  with  any  useful  degree  of  accuracy  how  many  pounds  of 
oxygen  one  million  gallons  of  sewage  will  require  in  order  that  the  putrefiable  in- 
gredients may  be  rendered  inert.    The  two  ways  of  approaching  this  subject,  that  is, 


DIGESTION  OF  SEWAGE  AND  EXHAUSTION  OF  OXYGEN  633 

by  analysis  and  incubation  tests,  are,  unfortunately,  too  artificial  to  show  what  can 
reasonably  be  expected  in  nature.  Predictions  as  to  the  amount  of  oxygen  which 
would  be  present  if  a  given  quantity  of  sewage  was  to  be  discharged  into  a  given 
quantity  of  water  must,  in  the  present  state  of  knowledge,  be  considered  unreliable. 

But  if  it  is  impossible  to  calculate  the  oxygen  requirements  of  sewage  or  express 
in  percentages  the  proportions  of  sewage  to  water  which  may  be  present  throughout 
a  harbor,  it  is  feasible  to  state,  in  at  least  approximate  terms,  the  relation  which 
exists  between  the  volume  of  sewage  and  the  volume  of  water  present  under  various 
circumstances  and  such  calculations  may  be  of  some  value.  They  are  likely  to  prove 
of  greatest  service  when  they  are  expressed  in  a  simple  way  and  are  used  with  other 
data  as  a  means  of  obtaining  a  general  opinion  of  the  case. 

It  was  in  this  way,  and  with  all  the  restrictions  and  qualifications  which  a 
knowledge  of  the  situation  imposed,  that  Professor  Adeney,  in  a  report  to  the  Metro- 
politan Sewerage  Commission,  calculated  the  dilution  of  sewage  in  New  York  harbor. 
(See  p.  95,  Report  Metropolitan  Sewerage  Commission,  August,  1912.) 

Calculations  op  Dilution 

Taking  his  data  from  the  published  reports  of  the  Commission,  Professor  Adeney 
calculated  that  about  59,400,000  cu.  ft.  of  sewage  flowed  into  the  whole  harbor  during 
a  tidal  cycle  of  12  lunar  hours.  Inasmuch  as  about  23  per  cent,  of  the  water  of  the 
harbor  flowed  out  on  the  ebb  tide,  the  same  percentage  of  the  contribution  of  sewage 
would  flow  to  sea  at  the  same  time,  leaving  about  77  per  cent,  mixed  with  the  harbor 
waters  at  mean  low  tide.  The  quantity  of  liquid  sewage  matters  subsequently  re- 
maining within  the  harbor  would  increase  with  each  succeeding  tidal  cycle  until  the 
quantitj'  which  passed  out  with  the  ebb  tide  became  equal  to  that  which  drained  into 
the  harbor  during  the  tidal  cycle.  This  would  occur  when  the  total  volume  of  liquid 
sewage,  remaining  intermixed  with  the  harbor  waters  at  mean  low  tide  had  become 
equal  to  about  195,500,000  cu.  ft.,  which  it  would  do  after  about  20  tidal  cycles.  The 
volume  of  liquid  sewage  matters  passing  out  of  the  harbor  through  the  Narrows  would 
then  continue  to  equal  the  volume  of  liquid  sewage  matters  flowing  into  the  harbor 
during  a  complete  tidal  cycle.  That  is,  if  59,490,000  cu.  ft.  of  sewage  passed  out  of 
the  harbor  with  each  12,310,000,000  cu.  ft.  of  ebbing  tide,  the  dilution  of  sewage  to 
water  would  be  in  the  proportion  of  1  to  200  and  the  dilution  to  the  liquid  sewage 
matters  remaining  in  the  harbor  at  mean  low  tide  would  be  in  like  proportion. 

Both  at  the  beginning  and  end  of  his  calculation,  Professor  Adeney  took  pains 
to  fully  explain  that  this  calculation  did  not,  as  no  calculation  could,  truly  represent 
the  facts. 


634         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

In  a  report  by  Messrs.  Black  and  Phelps,  made  to  the  Board  of  Estimate  and 
Apportionment  of  New  York  in  1909,  the  question  of  dilution  is  dealt  with  at  length, 
for  it  was  believed  to  have  an  important  bearing  on  the  question  of  dissolved  oxygen 
and  the  authors  considered  that  the  oxygen  should  not  fall  below  70  per  cent,  of  the 
amount  which  would  be  present  if  the  water  was  saturated  with  it. 

The  sources  of  the  water  in  each  principal  part  of  the  harbor  were  assumed  in 
accordance  with  volumes  and  velocities  stated  by  the  Coast  and  Geodetic  Survey  in 
1886,  and  the  proportion  of  water  from  each  source  was  apportioned  by  the  authors 
as,  in  their  judgment,  seemed  correct.  For  convenience — these  volumes  were  reduced 
to  percentages  of  the  whole  and  each  was  given  a  characteristic  letter  to  facilitate 
computation.  A  series  of  equations  was  derived  and  the  composition  of  the  water  of 
each  part  of  the  harbor  was  calculated  for  various  tidal  periods. 

These  studies  were  taken  by  the  authors  to  indicate  that  the  volume  of  pure  sea 
water  which  entered  the  harbor  between  the  Narrows  and  Throgs  Neck  every  12  hours 
was  29,135  million  gallons  and  that  this  contained  under  summer  conditions  1,946,218 
pounds  of  dissolved  oxygen.  It  was  considered  that  if  this  oxygen  were  to  be  reduced 
by  sewage  to  70  per  cent,  of  saturation,  583,865  pounds  would  be  lost  in  12  hours.  The 
total  volume  of  water  in  the  harbor  within  the  limits  named  was  taken  to  be  251,418 
million  gallons,  and  it  was  stated  that  if  this  were  reduced  to  70  per  cent,  of  sat- 
uration, it  would  absorb  in  12  hours  from  the  atmosphere  0.95  per  cent,  of  its  sat- 
uration value  of  159,550  pounds. 

The  oxygen  absorbed  from  the  atmosphere  plus  the  oxygen  from  the  pure  sea 
water  would  give  a  total  of  743,415  pounds  of  oxygen.  Finally,  assuming  that  the 
sewage  would  be  produced  at  the  rate  of  100  gallons  per  capita  per  day,  the  authors 
arrived  at  the  opinion  that  the  natural  supply  of  oxygen  would  be  sufficient  to  care 
for  the  sewage  of  a  population  of  7.4  millions,  provided  the  sewage  was  discharged  at 
the  two  ocean  entrances. 

A  study  of  the  dissolved  oxygen  reduced  the  difficulty  considerably  by  showing 
how  much  oxygen  has  been  used  up  and  how  much  remains,  thus  giving  a  better 
knowledge  of  the  water's  capacity  for  sewage  than  would  otherwise  be  obtainable. 

STATE  OF  THE  HARBOR  WITH  RESPECT  TO  DISSOLVED  OXYGEN  FROM 

1911  TO  1913 

Since  1909  the  Metropolitan  Sewerage  Commission  has  given  close  attention  to 
the  amount  of  oxygen  present  in  the  water.  Floating  laboratories  have  been  fitted  out 
with  every  requisite  for  careful  analytical  work  and  these  have  been  sent  to  all  parts 
of  the  harbor  to  collect  samples  of  the  water  and  analyze  them.    The  object  of  this 


DIGESTION  OF  SEWAGE  AND  EXHAUSTION  OF  OXYGEN  635 

field  work  has  been  twofold:  First,  to  determine  the  extent  to  which  the  digestive 
capacity  of  the  water  was  being  exhausted  and,  second,  to  determine  how  that 
capacity  could  safely  be  utilized  in  the  future. 

The  degree  to  which  the  oxygen  is  exhausted  has  been  determined  by  comparing 
the  amount  of  oxygen  which  is  present  with  the  known  quantity  which  would  be 
present  if  the  water  were  unpolluted.  The  standard  for  comparison  is  the  amount  of 
oxygen  which  exists  in  unpolluted  water  and  is  called  the  saturation  value.  The 
calculation  assumes  that  if  it  were  not  for  the  sewage  and  other  wastes  which  enter 
the  harbor,  the  saturation  values  would  obtain.  Tests  of  the  oxygen  in  the  polluted 
tributaries  of  New  York  harbor  and  in  uncontaminated  sea  water  and  determinations 
of  the  ammonias,  nitrites  and  nitrates  in  New  York  harbor  and  elsewhere  have  proved 
this  assumption  to  be  correct.  The  saturation  value  is  taken  from  tables  based  on 
carefully  made  laboratory  experiments.  The  amount  of  oxygen  in  the  water  is  con- 
veniently expressed  as  cubic  centimeters  per  liter  of  water  and  as  percentages  of  the 
saturation  value. 

The  amount  of  oxygen  present  in  unpolluted  water  varies  according  to  the  sal- 
inity and  temperature  of  the  water.  The  warmer  and  Salter  the  water,  the  less  oxygen 
it  can  contain.  These  differences  are  taken  into  account  in  calculating  the  results  of 
the  analyses.  In  very  careful  investigations,  it  is  desirable  to  give  attention  to  the 
amount  of  oxygen  actually  found,  as  well  as  to  the  percentage,  because  it  is  the  actual 
amount  of  oxygen  and  not  its  relative  amount,  or  percentage  of  saturation,  which 
determines  whether  the  water  will,  or  will  not,  putrefy.  In  all  the  Commission's 
tables  of  dissolved  oxygen,  these  two  methods  of  stating  the  results  have  been 
employed. 

The  samples  of  water  which  were  tested  were  obtained  in  bottles  protected  by 
special  apparatus  from  contamination  by  air  and  represented  the  exact  condition  of 
the  water  at  the  time  and  place  of  collection.  The  samples  were  always  the  best  that 
could  be  obtained  at  the  time  and  place.  In  no  case  have  samples  been  taken  at  the 
mouths  of  sewers  or  within  the  known  reach  of  currents  of  exceptionally  polluted 
water.  Where  samples  have  been  collected  close  to  shore,  or  in  particularly  polluted 
localities,  the  results  have  been  excluded  from  the  averages. 

A  prompt  analysis  of  the  water  showed  the  amount  of  oxygen  which  was  con- 
sumed by  the  sewage  materials  up  to  the  time  when  the  sample  was  collected.  A 
knowledge  of  the  extent  to  which  the  sewage  materials  would  exhaust  the  oxygen, 
when  more  time  was  allowed  for  decomposition,  was  obtained  by  keeping  the  sample 
on  hand  for  some  time  before  examining  it.  Such  storage  is  termed  incubation.  In 
practice  the  incubated  samples  were  collected  at  the  same  time  as  samples  that  were 


636         DATA  RELATING  TO  THE  PROTECTION  OP  THE  HARBOR 

analyzed  at  the  time  of  collection,  and  then  kept  for  a  definite  period  at  a  uniform 
temperature  without  access  of  air.  Several  hundred  samples  of  the  harhor  water 
were  incubated  by  the  Commission.  In  practically  all  cases  the  oxygen  was  greatly 
depleted. 

Changes  produced  in  the  oxygen  and  in  other  chemical  constituents  on  incubation 
are  shown  in  the  tables  accompanying  this  report. 

Summary  of  Facts  Established  to  November,  1911 

The  results  of  the  analyses  made  up  to  November,  1911,  have  been  published  by 
the  Commission  in  its  large  report  of  1912,  together  with  various  maps  and  diagrams 
intended  to  facilitate  an  understanding  of  the  facts.  The  total  number  of  analyses 
reported  was  2,342. 

The  work  done  since  1911  makes  available  the  results  of  1,368  more  analyses  and 
it  seems  desirable  that  the  most  important  facts  contained  in  this  mass  of  informa- 
tion should  be  published. 

In  the  report  of  1912,  the  inner  harbor,  by  which  is  meant  those  portions  which 
lie  north  of  the  Narrows  and  south  of  Hell  Gate  in  the  East  river  and  Mount  St.  Vin- 
cent on  the  Hudson  river,  was  shown  to  be  seriously  polluted  with  sewage.  During  the 
warm  summer  months  the  water  at  the  Narrows  averaged  76  per  cent.,  in  upper  New 
York  Bay  70  per  cent.,  in  the  lower  East  river  about  57  per  cent.,  and  that  in  the 
southern  part  of  the  Harlem  river  about  30  per  cent,  of  the  amount  which  they  would 
have  held  had  there  been  no  pollution. 

The  water  of  the  incoming  tide  was  better  than  the  water  of  the  outgoing  tide, 
but  the  difference  was  not  great.  The  tides  produced  less  improvement  in  the  lower 
East  river  than  anywhere  else.  The  upper  bay  was  a  great  equalizer,  so  far  as  oxygen 
was  concerned,  in  this  capacity  standing  between  the  relatively  clean  water  of  the 
lower  bay  and  the  heavily  polluted  East  and  Hudson  rivers  and  the  Kill  van  Kull  in 
this  respect. 

Outward  flowing  currents  carry  the  polluted  waters  of  the  Hudson,  East  river  and 
Kill  van  Kull  into  the  upper  bay,  where  they  mix  with  the  cleaner  waters  left  there  at 
the  end  of  the  last  flood  tide.  On  the  inward  flowing  currents,  the  bay  is  to  some  extent 
refreshed  by  the  waters  of  the  ocean  which  flow  in  through  the  Narrows. 

The  analyses  reported  upon  up  to  August,  1912,  show  that  there  was  little  differ- 
ence in  the  amount  of  oxygen  at  different  depths.  A  little  more  oxygen  generally 
existed  at  the  bottom  than  at  the  top.  Less  oxygen  existed  near  the  shores  than 
farther  out  in  midstream. 


DIGESTION  OF  SEWAGE  AND  EXHAUSTION  OF  OXYGEN  637 

Owing  to  the  rapidity  of  the  main  tidal  currents  which  flow  in  places  at  a 
velocity  of  from  6  to  8  knots  per  hour,  the  waters  in  all  the  main  parts  of  the  harbor 
are  well  mixed  from  top  to  bottom  and  from  side  to  side  except  in  certain  bays  and 
between  the  pierhead  lines  and  the  shores.  This  statement  does  not  refer  to  the  actual 
top,  bottom  or  sides;  these  are  always  far  more  polluted  than  the  water  in  the  main 
body  of  the  stream.  It  refers  to  the  water  which  lies  from  two  to  three  hundred  feet 
beyond  the  pierhead  line  on  one  shore  to  an  equal  distance  from  the  opposite  shore 
and  between  a  point  within  5  feet  of  the  top  to  a  depth  about  10  feet  above  the  bot- 
tom. At  the  very  top,  sides  and  bottom,  the  water  is  far  more  polluted  than  any  of 
the  Commission's  analytical  data  indicate.  In  some  localities,  it  is  impossible  to  tell 
such  water  from  sewage  itself.  Over  all  the  water  in  the  Harlem  and  Lower  East 
rivers  flow  considerable  quantities  of  grease  and  fecal  matters  at  times. 

There  is  considerable  difference  in  the  freedom  with  which  the  tidal  currents  flow, 
deep  bays  and  comparatively  shallow  indentations  in  the  shore  lines  affording  oppor- 
tunities for  slack  water  in  which  the  sewage  materials  gather  and  remain.  Irreg- 
ularities in  the  bottom  sometimes  cause  extensive  upwellings  of  water  in  the  center  of 
the  main  currents  and  occasionally  a  sharp  bend  in  the  channel  will  cause  a  remark- 
able overturning  of  the  water. 

Overturnings  are  also  caused  by  strong  winds  which,  blowing  along  the  surface 
force  the  water  at  and  near  the  top  to  the  lee  shores  and  pile  it  up  there,  the  under- 
lying waters  flowing  outward  from  beneath  to  maintain  an  equilibrium.  The  continual 
movement  of  vessels,  some  of  which  draw  over  30  feet,  doubtless  has  its  effect  in  pro- 
moting the  circulation  which  has  been  observed. 

The  changing  temperature  of  the  surface  water  under  the  influence  of  the  sun 
and  air  probably  has  an  effect  in  producing  a  vertical  circulation  which  cannot  wholly 
be  neglected.  For  six  months  in  the  year  the  surface  may  be  made  warmer  or  cooler 
than  the  water  below  and  these  differences  undoubtedly  produce  an  effect  upon  the 
circulation. 

Tending  to  prevent  a  thorough  mixture  of  the  sewage  with  the  harbor  waters  is 
the  great  weight  of  the  incoming  sea  water  due  to  its  low  temperature  and  its  high 
salinity.  This  weight  is  relatively  greater  than  the  weight  of  an  equal  volume  of 
sewage  and  the  sea  water  accordingly  tends  to  sink  and  remain  at  the  bottom.  On 
account  of  its  grease,  entrained  air,  low  salinity  and  higher  temperature,  the  sewage 
has  a  tendency  to  stay  at  the  surface  of  the  water  where  it  is  discharged.  That  it 
does  not  do  so  any  more  than  is  apparent  is  largely  due  to  the  strong  mixing  action 
produced  by  the  interacting  currents  in  the  main  tidal  channels. 

Although  the  waters  are  well  mixed  in  the  main  tidal  channels,  sewage  which  is 


638         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


1911  1913 

FIG.  37 


Dissolved  Oxygen  in  the  Water  Collected  in  the  Cross-Sections 


discharged  near  the  shores  tends  to  cling  there  and  be  carried  along  by  the  tide  with- 
out promptly  mixing  with  the  main  body  of  water  in  the  open  channels.  The  water 
between  the  slips  and  piers  is  often  very  foul  as  can  be  seen  not  only  from  analyses, 
but  by  the  unaided  senses.  The  refreshing  effect  of  the  tide  is  less  than  might  be 
expected ;  it  is  least  effective  where  it  is  most  needed ;  there  is  scarcely  any  perceptible 
effect  in  the  innermost  parts  of  the  harbor. 

The  Increasing  Exhaustion  of  Oxygen 

The  samples  collected  since  November,  1911,  represent  the  condition  of  the  water 
in  the  principal  parts  of  the  harbor  within  the  State  of  New  York.  In  some  cases 
samples  were  taken  within  the  New  Jersey  State  line.  For  the  most  part,  the  sampling 
was  done  at  cross-sections  which  experience  had  shown  were  capable  of  giving,  with 
the  least  expenditure  of  time  and  money,  the  most  comprehensive  knowledge  of  the 
condition  of  the  water.  Some  of  the  sections  were  in  the  most  important  parts  of 
the  harbor  as  regarded  from  the  standpoint  of  congestion  of  population  and  traffic. 
Others  were  so  located  as  to  command  the  main  tidal  currents  flowing  in  and  out  of 
the  harbor.    Special  interest  attaches  to  the  Harlem,  Lower  East  river,  Narrows  and 


DIGESTION  OF  SEWAGE  AND  E 


XHAUST10N  OF  OXYGEN  639 


The  Narrows  FIG.  39 

Hudson  River  at  Mount  St.  Vincent 


Hudson  River  at  Mouth  FIG.  41 

East  River  at  Pier  10 


FIG.  42  FIG.  43 

East  River  at  Lawrence  Point  East  River  at  Throgs  Neck 


Location  of  Cross-Sections  where  Samples  of  Water  for  Dissolved  Oxygen  Tests  were  Taken  in  1913 


640 


DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


Bay  on  n t 


the  mouth  of  the  Hudson  river.   The  location  of  sections  in  1911  and  1913  is  shown 
in  Fig.  37  and  details  as  to  depth  of  water,  etc.,  are  shown  in  Figs.  38  to  44,  inclusive. 
The  analyses  show  that  the  water  is  becoming  decidedly  more  contaminated  each 

year.  This  is  particularly  noticeable  in  three 
large  groups  of  analyses  made  during  the  two 
months  of  June  and  July  in  1909,  1911  and 
1913,  respectively.  Sketch  maps  of  the  harbor 
divisions,  showing  the  oxygen  in  each,  are 
given  as  Fig.  45. 

In  order  to  compare  the  summer  condi- 
tions during  June  and  July  of  the  three  years 
mentioned,  the  oxygen  results  obtained  have 
been  plotted  on  maps.    If  more  than  one 


JAILOR'S  o°  Snug  Harbor 

STA.X  E  n 


moo  vxs<y 


FIG.  44 

Kill  van  Kull  at  Sailor's  Snug  Harbor 


analysis  has  been  made  at  one  point,  the 


average  result  has  been  taken  without  respect  to  depth.  This  was  permissible  in  view 
of  the  fact  that  the  oxygen  did  not  vary  materially  with  the  depth  at  the  points 
selected.  The  result  of  the  average  has  been  plotted  alongside  of  the  point  where  the 
sample  was  located  on  the  map.  Arrows  and  small  numerals  show  how  many  samples 
were  taken  and  whether  on  ebb  or  flood  currents  at  each  spot.  See  Maps  A,  B,  C  and 
D,  following  pages  654,  670  and  706.  In  Figs.  46  to  55,  appended  to  this  report,  are 
plottings  of  the  data  which  show  the  distribution  of  oxygen  throughout  a  tidal  cycle  of 
12  lunar  hours,  and  through  the  cross-sections  where  analyses  were  made. 

At  the  mouths  of  the  Hudson  and  East  rivers,  the  per  cent,  of  oxygen  was  in  the 


FIG.  46 

Comparison  Between  the  Dissolved  Oxygen  in  New  York  Harbor  Water  in  the  Years  1909, 

1911  and  1913 


DIGESTION  OF  SEWAGE  AND  EXHAUSTION  OF  OXYGEN 


641 


neighborhood  of  58  on  ebb  currents  and  from  60  to  70  on  flood  currents  during  the 
summer  of  1909.  At  the  Narrows  the  per  cent,  on  outgoing  currents  was  from  72  to 
81,  and  on  incoming  currents  in  the  neighborhood  of  96  per  cent.  At  Throgs  Neck 
the  oxygen  on  outgoing  currents  varied  between  87  and  97  per  cent,  and  on  incoming 
currents  it  was  often  100  per  cent.  In  Upper  New  York  bay  outgoing  currents  con- 
tained between  58  and  73  per  cent.,  while  incoming  currents  contained  between  63 
and  75  per  cent. 

In  the  summer  of  1911  the  oxygen  was  less  on  both  outgoing  and  incoming  cur- 
rents than  had  previously  been  observed.  At  the  mouths  of  the  Hudson  and  East 
rivers  the  outgoing  currents  contained  from  50  to  59  per  cent,  and  incoming  currents 
from  54  to  60  per  cent.  At  the  Narrows  the  outgoing  currents  contained  65  per  cent, 
and  the  incoming  currents  83  per  cent.  Incoming  currents  in  the  Kill  van  Kull  con- 
tained from  62  to  66  per  cent.  In  Upper  New  York  bay  outgoing  currents  contained 
from  59  to  65  per  cent,  and  incoming  currents  from  62  to  70  per  cent.  At  Throgs 
Neck,  outgoing  currents  contained  71  per  cent,  and  incoming  currents  84  per  cent.  In 
the  Hudson  opposite  Mount  St.  Vincent,  about  2y2  miles  north  of  Manhattan  Island, 
the  incoming  currents  ranged  from  64  to  72  per  cent,  and  the  outgoing  currents  from  66 
to  83  per  cent,  of  oxygen. 

In  the  summer  of  1913,  the  range  of  dissolved  oxygen  at  the  mouth  of  the  Hudson 
was  from  43  to  53  per  cent,  on  incoming  currents  and  from  47  to  60  per  cent,  on  out- 
going currents.  At  the  mouth  of  the  Lower  East  river  the  range  was  from  39  to  48 
per  cent,  on  incoming  and  from  31  to  40  on  outgoing  currents.  These  figures  show 
that  the  oxygen  was  becoming  markedly  depleted  in  the  Lower  East  river.  At  the 
Narrows  the  range  was  from  67  to  74  per  cent,  on  incoming  and  from  67  to  78  per  cent, 
on  outgoing  currents.  At  the  Kill  van  Kull  the  range  was  from  64  to  66  per  cent,  on  in- 
coming and  from  65  to  67  on  outgoing  currents.  At  Throgs  Neck  from  76  to  85  per 
cent,  of  oxygen  was  found  on  incoming  currents  and  73  to  83  per  cent,  on  outgoing  cur- 
rents. In  the  Hudson  at  Mount  St.  Vincent,  incoming  currents  held  from  72  to  95  per 
cent,  and  outgoing  currents  from  76  to  85  per  cent,  of  the  normal  amount  of  oxygen. 
Upper  New  York  bay  in  1913  contained  about  70  per  cent,  on  incoming  and  outgoing 
currents. 

Averaging  all  the  analyses  made  in  the  Lower  East  river  except  a  few  in  1909 
in  the  excessively  polluted  region  of  Wallabout  bay,  it  appears  that  the  oxygen  in  this 
important  part  of  the  harbor  averaged,  during  the  months  of  June  and  July,  62.0  per 
cent,  in  1909,  54.6  per  cent,  in  1911  and  36.6  per  cent,  in  1913. 

The  oxygen  in  the  Hudson  opposite  Manhattan  Island,  considering  all  the  analyses 
made  between  the  confluence  of  the  Harlem  and  the  Hudson's  mouth,  has  been  62.8  per 
cent,  in  1909,  64.5  per  cent,  in  1911  and  52.2  per  cent,  in  1913. 


642         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

The  oxygen  figures  for  the  Harlem  make  no  attempt  to  cover  the  condition  of 
that  grossly  polluted  body  of  water.  The  92  analyses  made  of  this  water  show  that 
the  oxygen  averaged  47.7  per  cent,  in  1909,  46.1  per  cent,  in  1911  and  27.5  per  cent, 
iii  1913.    The  data  for  1911  represent  18  samples  collected  on  ebb  tide  in  July. 

It  will  be  seen  from  these  figures  that  all  the  waters  surrounding  Manhattan  are 
becoming  more  contaminated  as  time  proceeds  and  that  the  change  as  measured  by 
the  dissolved  oxygen  figures  is  rapid. 

Particular  interest  attaches  to  the  Lower  East  river  on  account  of  the  great 
importance  of  this  congested  part  of  the  harbor  and  because  of  the  great  difficulty 
with  which  the  conditions  can  be  improved.  In  1913  the  average  of  15  analyses  made 
in  the  middle  of  the  East  river  on  outgoing  currents  was  31  per  cent,  and  still  lower 
figures  than  these  were  found  in  this  locality.  At  the  same  point  and  under  the  same 
circumstances  there  was  57  per  cent,  in  the  year  1911  and,  in  1909,  61  per  cent.  The 
oxygen  had  become  reduced  from  about  two-thirds  to  about  one-third  of  the  saturation 
value  in  two  years. 

Essential  Facts  Relating  to  the  Cross- Sections. 

During  1911  and  1913  detailed  examinations  of  cross-sections  of  the  main  tidal 
channels  of  the  harbor  were  made  a  special  feature  of  the  work.  From  three  to  five 
points  spaced  at  equal  distances  apart  were  taken  across  the  channels,  and  at  each 
point  samples  were  collected  from  three  depths.  Sampling  usually  began  near  the 
beginning  or  end  of  a  tide  and  was  continued  throughout  the  succeeding  tidal  cycle, 
Seven  of  these  cross-sections  were  studied  in  1913,  the  number  of  samples  collected 
from  the  most  important  of  them  being  167. 

Comparing  the  work  of  1913  with  that  done  in  1911  and  stating  the  case  in  gen- 
eral terms,  the  diffusion  of  the  sewage  in  the  water  was  not  as  complete  in  1913  as  it 
was  in  1911 ;  the  curves  plotted  from  the  data  show  the  variations  plainly. 

In  1911  there  was  often  a  gradual  decrease  in  the  effects  of  pollution  at  the  be- 
ginning of  flood  currents;  in  1913  a  rapid  rise  occurred.  The  rise  in  oxygen  was  not 
only  more  abrupt,  but  was  not  uniform  at  all  points  in  the  cross-section  examined. 

Variations  in  the  quality  of  the  water  at  different  depths  were  often  pronounced 
in  1913,  whereas  such  differences  were  inconspicuous  in  1911. 

With  the  exception  of  the  Hudson  river  at  Mount  St.  Vincent  there  was  evidence 
of  greater  pollution  in  all  the  cross-sections  in  1913  than  in  1911.  At  Mount  St.  Vin- 
cent there  was  somewhat  more  oxygen  in  1913  than  formerly.  At  this  point  the  water 
was  better  during  the  ebb  current  than  when  the  current  flowed  from  the  direction  of 
the  sea.    It  is  accounted  for  by  the  fact  that  the  sea  water  brought  sewage  materials 


DIGESTION  OF  SEWAGE  AND  EXHAUSTION  OF  OXYGEN  643 

from  New  York  City,  whereas  the  ebb  currents  were  from  the  relatively  little  pol- 
luted Upper  Hudson.  This  difference  was  marked  in  1913.  In  1911  there  was  more 
oxygen  at  the  top  than  at  the  bottom  during  flood  currents  in  most  parts  of  the  harbor, 
but  in  1913  there  was  slightly  more  at  the  bottom  and  in  midstream  than  at  the  top. 

There  was  less  oxygen  at  the  mouth  of  tbe  Hudson  river  in  1913  than  in  1911  and 
the  variation  was  greater  in  the  latter  year,  both  as  to  the  amount  of  oxygen  found  at 
different  depths  and  at  different  points  between  the  shores.  In  1911  there  was  a 
gradual  rise  in  the  oxygen  following  the  beginning  of  flood  currents;  in  1913  this  rise 
was  abrupt  and  marked. 

At  the  mouth  of  the  East  river,  the  water  was  much  more  polluted  in  1913  than  in 
1911,  as  measured  by  the  oxygen.  At  the  beginning  of  flood  currents  there  was  a 
sharp  rise  in  the  oxygen;  a  very  gradual  rise  occurred  at  this  place  under  the  same 
tidal  conditions  in  1911.  Whereas  in  1911  there  had  occurred  a  slight  fall  in  the 
amount  of  oxygen  throughout  the  ebb  current,  in  1913  this  fall  was  decided.  Of  all 
these  differences,  chief  significance  attaches  to  the  fact  that  the  Lower  East  river  has 
been  growing  more  and  more  polluted. 

Summary  op  Details  Relating  to  Special  Localities 
The  Loicer  East  River. — It  is  not  apparent  why  the  Lower  East  river  should  in- 
crease so  rapidly  in  pollution  as  it  has  in  the  last  four  years.  Some  increase  might 
be  expected  from  the  increase  in  the  population  whose  sewage  is  directly  tributary  to 
this  part  of  the  harbor,  but  the  increase  would  not,  apparently,  suffice  to  produce  such 
a  change  in  the  oxygen  figure  as  has  been  observed.  It  is  possible  that  the  increasing 
pollution  of  the  Harlem  and  Upper  East  rivers,  which  are  immediately  tributary  to 
the  Lower  East  river,  and  the  polluting  effect  of  the  Gowanus  Flushing  Tunnel,  which 
discharges  at  the  mouth  of  the  Lower  East  river,  may  account  in  large  part  for  the 
reduction. 

The  condition  of  the  Lower  East  river  calls  imperatively  for  improvement.  As 
shown  in  Preliminary  Report  No.  VI*  of  this  Commission,  issued  February,  1913,  the 
quantity  of  sewage  now  discharging  into  this  part  of  the  harbor  is  very  large  and 
will  greatly  increase  in  future.  The  ratio  of  sewage  to  the  excess  of  water  flowing 
seaward  was  as  1  to  5.9  in  the  year  1910  and  by  the  year  1940  will  be  as  1  to  3.2. 

It  is  probable  that  there  is  no  other  city  in  the  world  within  whose  crowded  dis- 
tricts so  much  sewage  is  discharged.  In  1910  the  daily  addition  of  sewage  was  264 
million  gallons  from  a  population  of  about  2,000,000.  This  quantity  will  increase  until 
by  the  year  1940  it  is  estimated  that  there  will  be  discharged  into  the  East  river 
between  Hell  Gate  and  the  Battery  454  million  gallons  from  a  population  of  about 

*Part  II,  Chap.  II,  page  46,  this  report. 


644         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

3,223,000.  In  addition  to  this  there  will  be  the  densely  polluted  water  of  the  Harlem 
flowing  in  at  each  tide. 

The  large  demand  which  the  sewage  makes  upon  the  oxygen  in  the  rest  of  the 
harbor  is  doubtless  due  in  part  to  the  polluted  water  of  the  East  river,  in  part  to  the 
sewage  which  directly  enters  it  and  in  part  to  deposits  of  sewage  sludge  which  lie  on 
the  bottom.  These  deposits  are  stirred  up  by  the  movement  of  vessels  and  by  tidal 
actions  and,  putrefying,  give  off  products  which  consume  a  good  deal  of  the  oxygen. 

The  report  of  this  commission  issued  August,  1912,  shows  the  location  of  the  most 
extensive  sludge  deposits.  They  are  mostly  in  the  more  open  parts  of  the  harbor. 
Other,  if  less  extensive,  deposits  exist,  notably  in  the  slips  and  in  innumerable  quiet 
places  around  the  water  front. 

Excepting  for  the  deposits  of  sludge  along  the  shores,  there  is  practically  no 
sludge  upon  the  bottom  of  the  Lower  East  river.  The  water  of  that  part  of  the  har- 
bor is  deficient  in  oxygen  because  of  the  demand  which  is  made  by  the  sewage  which 
directly  enters  it  and  because  the  water  which  enters  it  from  parts  of  the  harbor  which 
are  themselves  polluted  is  deficient  in  oxygen. 

The  Harlem  River. — Analyses  are  scarcely  capable  of  showing  the  condition  of  the 
Harlem  river.  An  inspection  of  the  water  affords  far  more  striking  evidence  of  the 
intensity  of  pollution.  In  the  neighborhood  of  110th  Street  the  water  is  often  so  con- 
taminated as  to  resemble  undiluted  sewage.  The  water  is  turbid  and  greasy  and  fecal 
matters  are  conspicuously  present.  This  appearance  sometimes  extends  from  shore  to 
shore.  The  musty,  sweetish  odors  are  characteristic  of  fresh  sewage.  Deposits  of 
sewage  materials  occur  here  and  putrefy,  giving  off,  in  summer,  bubbles  of  gas  which 
burst  at  the  surface  of  the  water  causing  it  to  resemble  the  appearance  of  falling  rain. 

The  dilution  of  sewage  with  water  in  the  Harlem  river  was,  in  the  year  1910,  very 
small,  no  matter  how  reckoned.  The  ratio  of  the  sewage  to  the  net  ebb  flow  of  the 
tide,  which  is  the  quantity  of  water  which  flows  in  one  direction  in  excess  of  the  water 
which  flows  in  the  opposite  way  was  as  1  to  2.2.  By  the  year  1940,  the  increasing 
amount  of  sewage  will  reduce  this  dilution  so  that  it  will  be  as  1  is  to  0.85.  In  other 
words,  by  1940  there  will  be  more  sewage  entering  the  Harlem  river  than  water  pass- 
ing through  that  stream. 

The  condition  of  the  Harlem  is  the  most  serious  which  confronts  the  City  of  New 
York  at  the  present  time.  Not  only  is  the  water  objectionable  from  the  standpoint  of 
the  Harlem  itself,  but,  pouring  out  alternatively  into  the  Hudson  and  East  river,  the 
polluted  Harlem  adds  materially  to  the  pollution  of  each.  Six  samples,  collected  at  its 
junction  with  the  Hudson  in  1911,  when  the  current  was  carrying  the  water  of  the 
Harlem  into  the  Hudson,  contained  but  17  per  cent,  of  oxygen,  and  on  another  occa- 


DIGESTION  OF  SEWAGE  AND  EXHAUSTION  OF  OXYGEN  645 

sion  when  the  water  was  flowing  into  the  East  river  at  Hell  Gate  the  oxygen  was  about 
as  far  gone. 

The  Upper  East  River. — The  waters  of  the  Upper  East  river  are,  as  yet,  not  so 
heavily  polluted  as  to  require  the  immediate  construction  of  extensive  sewage  disposal 
works.  Yet  the  increasing  pollution  to  which  this  part  of  the  harbor  will  be  subject 
in  the  next  thirty  years  leaves  little  doubt  but  that  the  conditions  which  now  exist  in 
the  Lower  East  river  and  Harlem  will  be  repeated  unless  steps  are  taken  to  protect 
the  waters.    Plans  should  be  adopted  for  the  future  without  delay. 

Already  the  water  at  the  west  end  of  the  Upper  East  river  has  been  found  to  con- 
tain only  about  45  per  cent,  of  oxygen  when  the  currents  are  flowing  northward,  and  a 
long  series  of  analyses  at  this  point  made  in  the  summer  of  1913  showed  that  the 
water  was  never  in  satisfactory  condition. 

Some  large  sewers  discharge  into  the  Upper  East  river  and  in  the  vicinity  of 
their  outlets  the  conditions  of  pollution  are  very  bad.  The  discharge  of  the  Hunt's 
Point  sewer  can  often  be  seen  a  mile  or  more  away.  The  existence  of  popular  places  of 
recreation  in  the  Upper  East  river  makes  it  especially  desirable  to  keep  this  water 
reasonably  clean. 

The  Hudson  River. — Notwithstanding  the  relatively  large  amount  of  water  in  the 
Hudson  available  for  diluting  sewage  and  in  spite  of  the  considerable  net  discharge  of 
this  body  of  water  seaward,  the  condition  of  the  Hudson  is  fast  becoming  unsatis- 
factory. The  best  water  obtainable  from  this  part  of  the  harbor  in  the  summer  of 
1911  ranged  from  56  to  63  per  cent.,  and  results  in  the  vicinity  of  the  lower  figure 
have  been  common. 

The  Kill  van  Kail. — The  dissolved  oxygen  in  the  Kill  van  Kull  shows  plainly  the 
pollution  to  which  that  part  of  the  harbor  is  subject.  In  1913  the  percentage  was 
below  70.  There  was  little  difference  between  the  quality  of  the  incoming  and  out- 
going tidal  currents;  the  water  which  entered  this  part  of  the  harbor  was  polluted 
in  each  case. 


DISSOLVED  OXYGEN  IN  THE  WATER 


647 


SECTION  III 

TABLES  OF  DISSOLVED  OXYGEN  IN  THE  WATER 

INTRODUCTION  TO  TABLES  CXVI,  CXVII,  CXVIII,  CXIX 

The  dissolved  oxygen  found  in  the  year  1911  at  various  localities,  depths  and  tides, 
have  been  computed  from  the  data  contained  in  Table  XXVII,  Report  of  Metropolitan 
Sewerage  Commission,  1912,  pages  314-411.  In  Table  CXIX  of  the  present  report  is 
given  a  summary  of  the  results  of  these  calculations.  Tables  CXVI,  CXVII  and 
CXVIII  give  the  results  used  in  making  these  averages. 


648  DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

TABLE  CXVI 

Average  Volume  and  Percentage  of  Saturation  of  Dissolved  Oxygen  in  the  Water  in  the  Year  1911 

Averages  for  various  parts  of  the  harbor 


Data  for  this  table  are  contained  in  Table  XXVII,  Report  of  Metropolitan  Sewerage  Commission,  1912. 


T  ifipp  t  inn 

Number 
of 

analyses 

Averages: 

C.  C. 
per  litre 

Averages: 

nop  fpnt 

saturation 

SI i  mri  oa  in  f*l  i iri orl  in  f  no  o  upro  cr 
Ou.m jjkjs  uiL i ULii. (i  in  tile  averages 

Upper  bay  

195 

4 

35 

73 

92-94,  110-112,  260-274,  349-357,  373-381,  400-402,  841-843,  2038- 

2094,  2098-2109,  2113-2124,  2128-2139,  2143-2154,  2158-2169,  2230- 

2244,  2251-2265,  2275-2276,  2339. 

Hudson  river,  below 

Spuyten  Duy vil . . 

345 

o 
0 

A  *7 

61 

20-22,  137-169,  275-310,  463-522,  538-551,  556-588,  903-947,  1579- 

1683  9997— 999Q  99fifi_9974.  9^1fi-9318  9'fofi 

Hudson  river,  above 

Spuyten  Duy  vil . . 

158 

4 

yi 

78 

23-52,  170-181,  311-322,  352-355,  589-597,  1948-2037,  2337. 

East    river,  below 

Hell  Gate  

217 

Q 
O 

uo 

55 

95-106,  113-124,  598-642,  76S-812,  815-816,  821-822,  825-828,  952- 

954,  1684-1773,  2338,  2342. 

East    river,  above 

Hell  Gate  

253 

3 

99 

69 

53-91,  107-109,  125-127,  418-462,  523-537,  643-657,  691-699,  728-733, 

955-960,  1894-1947,  2173-2226,  2301-2303,  2306-2308,  2334. 

52 

2 

28 

43 

182-225,  833-840. 

Kill  van  Kull  

78 

4 

19 

72 

403-414,  844-855,  1774-1827. 

The  Narrows  

168 

4 

43 

78 

358-360,  382-384,  876-902,  1474-1578,  2095-2097,  2110-2112,  2125- 

2127,  2140-2142,  2155-2157,  2170-2172,  2245-2250,  2287-2292. 

25 

1 

90 

20 

12-19,  128-136,  690-693,  948-951. 

Newtown  creek  

8 

1 

14 

17 

2319-2326. 

Wallabout  canal. . . . 

2 

1 

67 

30 

2279-2280. 

Long  Island  Sound . 

22 

4 

74 

93 

700-705,  722-727,  961-966,  2309-2311,  2333. 

Newark  bay  

82 

3 

92 

63 

415-417,  856-867,  1828-1893,  2335. 

Passaic  river,  near 

Newark  

8 

0 

00 

0 

868-875. 

Lower  bay  

44 

5 

39 

97 

361-366,  385-396,  734-753,  761-767,  2340-2311. 

Buttermilk  channel. 

68 

2 

91 

54 

3-11,  230-235,  240-242,  247-255,  323-328,  333-337,  340-345,  658-663, 

668-679,  684-689. 

Manhasset  bay  

16 

5 

24 

97 

706-721. 

Cheesequake  creek.. 

10 

5 

44 

100 

754-763. 

Atlantic  ocean  

9 

5 

66 

100 

367-372,  397-399. 

1760     Total  number  of  samples  included  in  the  averages. 


Note. — The  following  samples  are  omitted,  having  been  taken  in  slips  and  too  near  shore: 

East  river  below  Hell  Gate,  813-814,  817-820,  823-824,  2281-2282,  2304-2305   12 

East  river  above  Hell  Gate,  2283-2284,  2331-2332   4 

Harlem  river,  829-832,  2285-2286,  2293-2300,  2327-2330   18 

Buttermilk  channel,  1-2,  226-229,  236-239,  243-246,  256-259,  329-332,  338-339,  346-348,  664-667, 

680-883,  2277-2278,  2312-2315   41 

75 

Trip  through  Long  Island  Sound  and  Boston  Harbor,  967-1473   507 

Total  omitted   682 

Total  included  in  averages   1760 

Total  analyses,  Nos.  1-2342   2342 


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DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


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DISSOLVED  OXYGEN  IN  THE  WATER  653 
TABLE  CXVIII 

Average  Volume  and  Percentage  of  Saturation  of  Dissolved  Oxygen  in  the  Water  in  the  Year  1911 
Averages  of  samples  taken  on  Ebb  and  Flood  Currents  for  various  parts  of  the  harbor 

Data  for  this  table  are  contained  in  Table  XXVII,  Report  of  Metropolitan  Sewerage  Commission,  1912. 


Location 


Upper  bay. 


Hudson  river,  below 
Spuyten  Duyvil. . . 


Hudson  river,  above 
Spuyten  Duyvil . . . 


East  river,  below  Hell 
Gate  

East  river,  above  Hell 
Gate  

Harlem  river  

Kill  van  Kull  

The  Narrows  

Gowanus  canal  

Newtown  creek  

Wallabout  canal  

Long  Island  Sound.. . 
Newark  bay  

Passaic    river,  near 

Newark  

Lower  bay  

Buttermilk  channel. . 

Manhasset  bay  

Cheesequake  creek. . . 
Atlantic  ocean  


Currents 


Ebb  Currents 


m 

C  tn 


102 


246 


113 


115 


115 


22 
30 
118 


15 
40 


8 
39 


O 

O  S 


=?  Sr 

U 

X 

< 


4.29 


3.51 


5.06 


2.96 


4.45 


.06 
.16 
4.22 


1.68 


4.70 
3.90 


0.00 
5.04 
2.79 

5.09 

5.61 


72 


62 


SI 


53 


77 


38 
72 
74 


31 


94 
64 


0 
87 
.52 

95 

100 


Samples  included  in  the  averages 


92-94,  260-269,  349-357,  841-843, 
2038-2047,  2050,  2053,  2098-2109 
2113-2124,  2143-2154,  2158-2169, 
2251-2265,  2276,  2339. 

20-22,  137-169,  278-310,  463-492 
538-551,  556-588,  918-947,  1579- 
1608,  1654-1683,  2266-2274,  2336. 

38-52,  170-181,  311-322,  352-355, 
589-597,  1948-1977,  2008-2037, 
2337. 


95-106,  613-642,  768-782,  815-816, 
821-822,  825-828,  952-954,  1684- 
1698,  1744-1773,  2338,  2342. 

68-91,  107-109,  643-657,  728-733, 
955-960,  1921-1947,  2173-2181, 
2200,  2209-2226,  2301-2303,  2306- 
2308. 
182-203. 

844-855,  1783-1800. 
358-360,  876-902,  1474-1485,  1519- 
1578,  2110-2112,  2125-2127,  2155- 
2157,  2170-2172,  2248-2250,  2287. 


948-951. 

No  samples  on  ebb  current. 
No  samples  on  ebb  current. 
722-727,  961-966,  2309-2311. 
856-867, 1828-1830, 1833-1843, 1859- 
1871,  2335. 


868-875. 

361-366,  2340-2341. 

11,  230-235,  240-242,  247-255,  674- 
679,  684-689. 
706-713. 

No  samples  on  ebb  current. 
367-372. 


Flood  Currents 


u 

rj  g 
. .  — 

u  c 

:  - 
SX'S 
..  zi 

a  b 
m  3 

Z  a 

Ci 

c 

=3  8 
-  C~ 
o 

> 

- 

£  So 

>  c 
<  § 

Samples  included  in  the  averages 

93 

4.43 

73 

110-112,  270-274,  373-381,  400-402, 
2048-2049,  2051-2052,  2054-2094, 
2128-2139,  2230-2244,  2275. 

99 

3.36 

59 

275-277,   493-522,   903-917,  1609- 
1653,  2227-2229,  2316-2318. 

45 

4.55 

71 

23-37,  1978-2007. 

102 

3.17 

57 

113-124,   598-612,   783-812,  1699- 
1743. 

138 

3.60 

62 

53-67,   125-127,  418-462,  523-537, 
694-699,    1894-1920,  2182-2199, 
2201-2208,  2334. 

30 
48 
50 

2.43 
4.25 
4.94 

46 
73 
86 

204-225,  833-840. 
403-414,  1774-1782,  1801-1827. 
382-384, 1486-1518,  2095-2097,  2140- 
2142,  2245-2247,  2288-2292. 

21 
8 
2 
7 

42 

1.94 
1.14 
1.67 
5.12 
3.94 

35 
17 
30 
92 
63 

12-19,  128-136,  690-693. 
2319-2396. 
2279-2280. 
700-705,  2333. 

415-417, 1831-1832, 1844-1858, 1872- 
1893. 

36 
29 

8 
10 
3 

5.46 
3.07 

5.41 
5.44 
5.76 

99 
58 

99 
100 
100 

No  samples  on  flood  current. 
385-396,  734-753,  764-767. 
323-328,  333-337,  340-345,  658-663, 

668-673. 
714-721. 
754-763. 
397-399. 

DISSOLVED  OXYGEN  IN  THE  WATER 


655 


INTRODUCTION  TO  TABLES  CXX,  CXXI,  CXXII,  CXXIII,  CXXIV 
The  analyses  for  oxygen  made  in  the  year  1912  were  made  in  the  same  manner  and 
by  the  same  persons  as  in  the  years  1909  and  1911.  The  total  number  taken  was  less 
than  in  either  of  the  two  previous  years,  and  the  averages  shown  in  Tables  CXXI, 
CXXII,  CXXIII  and  CXXIV  may  not  be  as  truly  representative  of  mean  conditions 
as  those  obtained  in  other  years  and  from  a  larger  number  of  samples.  The  results  found 
from  analyses  made  at  various  localities,  depths  and  tides  have  been  computed  from 
data  contained  in  Table  CXX,  and  are  given  in  Tables  CXXI,  CXXII  and  CXXIII. 
In  Table  CXXIV  is  given  a  summary  of  the  results  of  these  calculations. 


656 


DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


TABLE  CXX 

VOLUME  AND  PERCENTAGE  OF  SATURATION  OF  DISSOLVED  OXYGEN  IN  THE  WATER 

IN  THE  YEAR  1912 

Table  of  Contents 

Section  Date  of 

No.  Location  Collection  Page 

1  East  river,  Hudson  river,  Upper  bay  and  Narrows  Feb.  27, 1912   657 

2  East  river,  Hudson  river,  Upper  bay,  Kill  van  Kull  and  Narrows  Mar.  4,1912   657 

3  East  river,  Hudson  river,  Upper  bay,  Kill  van  Kull  and  Narrows  Mar.  5,1912   657 

4  East  river,  Hudson  river,  Upper  bay,  Kill  van  Kull  and  Narrows  Mar.  14,  1912   658 

5  East  river,  Hudson  river,  Upper  bay,  Kill  van  Kull  and  Narrows  Apr.    3,1912   658 

6  Passaic  river  at  West  Arlington  and  at  Newark,  N.  J  Apr.    5,1912   659 

7  Hudson  river  and  East  river  Apr.  16,1912   659 

8  East  river,  Hudson  river,  Upper  bay,  Kill  van  Kull  and  Narrows  June  13,  1912   659 

9  Narrows,  Kill  van  Kull,  Upper  bay,  Hudson  river  and  East  river  June  13,  1912   660 

10  East  river,  Hudson  river,  Upper  bay,  Kill  van  Kull  and  Narrows  July  11,  1912   660 

11  East  river,  Hudson  river,  Upper  bay,  Kill  van  Kull  and  Narrows  July  24,  1912   661 

12  Gowanus  canal  and  De  Graw  st.  slip,  Brooklyn  Aug.  13,  1912   661 

13  Slips  in  Hudson  river  and  Harlem  river  Aug.  16,  1912   661 

14  Hudson  river,  Cross-section  at  Pier  A  Sept.  13,  1912   662 

15  East  river,  Cross-section  below  Brooklyn  Bridge  Sept.  26,  1912   663 

16  Cross-section  of  the  Narrows  Oct.    4,1912   664 

17  East  river,  Cross-section  below  Brooklyn  Bridge  Nov.  26, 1912   665 


DISSOLVED  OXYGEN  IN  THE  WATER 


657 


TABLE  CXX 

1 — EAST  RIVER,  HUDSON  RIVER,  UPPER  BAY  AND  NARROWS.    FEBRUARY  27,  1912 

High  water  occurred  at  Governors  Island  at  3.00  P.  M.  Low  water  at  11.10.  The  wind  was  northwest,  with  a  ve  o„ 
40  miles  per  hour. 


Sample 
No. 


Hour 
A.  M. 


Location  of  Samples 


Approximate 

East  river,  midstream,  at  Brooklyn 

Bridge  

East  river,  midstream,  at  Brooklyn 

Bridge  

Hudson  river,  midway  between  Pier  A 

and  C.  R.R.  of  N.  J.  ferry  

Hudson  river,  midway  between  Pier  A 

and  C.  R.R.  of  N.  J.  ferry  

Narrows,  midway  between  forts  

Narrows,  midway  between  forts  

Upper  bay,  near  Robbins  Reef  bell 
buoy  

Upper  bay,  near  Robbins  Reef  bell 
buoy  


Latitude 


Longitude 


Feet 
below 
surface 


Tidal 
current 


Temp, 
water 
Deg.  C. 


Per 
cent, 
land 
water 


Oxygen 


C.  C. 
per 
litre 


Per 
cent, 
satura- 
tion 


10.30 
10.40 
11.30 
11.40 


40  42  20 
40  42  20 
40  42  19 
40  42  19 


73  59  48 

73  59  48 

74  01  34 
74  01  34 


1 

30 
1 

30 


Ebb 
Ebb 
Ebb 
Ebb 


2.2 
3.3 
2.8 
2.8 


24 
24 
34 
34 


6.57 
6.57 
6.57 
6.57 


80 
80 
80 
80 


P.  M. 
12.30 

12.40 
1.15 


1.25 


40  36  25 
40  36  25 
40  39  10 

40  39  10 


74  02  48 
74  02  48 
74  03  50 

74  03  50 


1 

60 
1 

40 


End  of 
Ebb 
Flood 

End  of 
Ebb 

Flood 


2.8 
3.3 


2.8 
2.8 


30 
16 


32 
28 


7.57 
7.71 


7.14 
7.28 


92 
98 


87 
89 


2— EAST  RIVER,  HUDSON  RIVER,  UPPER  BAY,  NARROWS  AND  KILL  VAN  KULL.    MARCH  4,  1912 


High  water  occurred  at  Governors  Island  at  8.40  A.  M.  Low  water  at  3.15  P.  M.  The  wind  was  east,  with  a  velocity  of 
5  miles  per  hour. 


A.  M. 

9 

10.30 

East  river,  midstream,  at  Brooklyn 

Bridge  

40  42  20 

73  59  48 

1 

Ebb 

1 

7 

24 

6.57 

79 

10 

10.35 

East  river,  midstream,  at  Brooklyn 

Bridge  

40  42  20 

73  59  48 

30 

Ebb 

2 

2 

24 

6.57 

80 

11 

11.00 

Hudson  river,  midstream,  off  Pier  A .  . 

40  42  19 

74  01  34 

1 

Ebb 

1 

1 

32 

6.86 

81 

12 

11.05 

Hudson  river,  midstream,  off  Pier  A . . 

40  42  19 

74  01  34 

30 

Ebb 

1 

7 

32 

6.86 

82 

13 

11.30 

Upper  bay,  near  Robbins  Reef  bell 

40  39  10 

74  03  50 

1 

Ebb 

1 

1 

24 

7.14 

85 

14 

11.35 

Upper  bay,  near  Robbins  Reef  bell 

buoy  

40  39  10 

74  03  50 

40 

Ebb 

1 

7 

24 

7.14 

86 

15 

12.00 

Kill  van  Kull,  midstream,  at  Sailors 

Snug  Harbor  

40  38  50 

74  06  25 

1 

Ebb 

1 

1 

36 

7.14 

83 

P.  M. 

16 

12.05 

Kill  van  Kull,  midstream,  at  Sailors 

Snug  Harbor  

40  38  50 

74  06  25 

30 

Ebb 

1 

7 

36 

7.14 

84 

17 

1.00 

The  Narrows,  midway  between  forts. . 

40  36  25 

74  02  48 

1 

Ebb 

1 

1 

22 

7.43 

88 

18 

1.05 

The  Narrows,  midway  between  forts . . 

40  36  25 

74  02  48 

60 

Ebb 

1 

7 

22 

7.43 

88 

3— EAST  RTVER,  HUDSON  RIVER,  UPPER  BAY,  KILL  VAN  KULL  AND  NARROWS.    MARCH  5,  1912 


High  water  occurred  at  Governors  Island  at  9.15  A.  M.  Low  water  at  3.45  A.  M.  The  wind  was  southeast,  with  a  velocity  of 
10  mUes  per  hour. 


A.  M. 

19 

6.05 

East  river,  midstream,  at  Brooklyn 

Bridge  

40  42  20 

73  59  48 

1 

Flood 

0 

6 

28 

6.86 

80 

20 

6.10 

East  river,  midstream,  at  Brooklyn 

40  42  20 

73  59  48 

30 

Flood 

1 

1 

28 

6.86 

80 

21 

6.25 

Hudson  river,  midstream,  off  Pier  A . . 

40  42  19 

74  01  34 

1 

Flood 

0 

6 

32 

7.00 

81 

22 

6.30 

Hudson  river,  midstream,  off  Pier  A .  . 

40  42  19 

74  01  34 

30 

Flood 

1 

1 

32 

7.00 

82 

658 


DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


TABLE  CXX— Continued 

3— EAST  RIVER,  HUDSON  RIVER,  UPPER  BAY,  KILL  VAN  KULL  AND  NARROWS.    MARCH  6,  1912— Continued 


Sample 
No. 


Hour 
A.  M. 


Location  of  Samples 


Approximate 

Upper  bay,  near  Robbins  Reef  bell 

buoy  

Upper  bay,  near  Robbins  Reef  bell 

buoy  

Kill  van  Kull,  midstream,  at  Sailors 

Snug  Harbor  

Kill  van  Kull,  midstream,  at  Sailors 

Snug  Harbor  

The  Narrows,  midway  between  forts . . 
The  Narrows,  midway  between  forts. . 


Latitude 


Longitude 


Feet 
below 
surface 


Tidal 
current 


Temp, 
water 
Deg.  C. 


Per 

cent, 
land 
water 


Oxygen 


C.  C. 
per 
litre 


Per 
cent, 
satura- 
tion 


23 
24 
25 
26 


27 

28 


7.00 
7.05 
7.30 
7.35 


40  39  10 
40  39  10 
40  38  50 
40  38  50 


74  03  50 
74  03  50 
74  06  25 
74  06  25 


1 

40 
1 

30 


Flood 
Flood 
Flood 
Flood 


0.6 
1.1 
0.6 
1.1 


24 
24 
24 
24 


7.43 
7.43 
7.14 
7.14 


88 
89 
84 
85 


8.10 
8.15 


40  36  25 
40  36  25 


74  02  48 
74  02  48 


1 

60 


Flood 
Flood 


0.6 
1.1 


20 
16 


8.15 
8.00 


96 
97 


4— EAST  RIVER,  HUDSON  RIVER,  UPPER  BAY,  KILL  VAN  KULL  AND  NARROWS.    MARCH  14,  1912 

High  water  occurred  at  Governors  Island  at  6.30  P.  M.    Low  water  at  12.20  A.  M.    The  wind  was  southwest,  light. 


29 

A.  M. 
11.15 

30 

11.20 

31 

32 

11.50 
12.00 

33 

P.  M. 
12.30 

34 

12.40 

35 

1.10 

36 

1.20 

East  river,  midstream,  at  Brooklyn 

Bridge  

East  river,  midstream,  at  Brooklyn 

Bridge  

Hudson  river,  midstream,  off  Pier  A . . 
Hudson  river,  midstream,  off  Pier  A . . 


40  42  20 

40  42  20 
40  42  19 
40  42  19 


73  59  48 

73  59  48 

74  01  34 
74  01  34 


30 
1 
30 


Ebb 

Ebb 
Ebb 
Ebb 


4.4 

4.4 
3.3 
3.9 


40 

40 
84 
44 


6.43 

6.43 
6.86 
6.43 


37 
38 


Upper  bay,  near  Robbins  Reef  bell 

buoy  

Upper  bay,  near  Robbins  Reef  bell 

buoy  

Kill  van  Kull,  midstream,  off  Sailors 

Snug  Harbor  

Kill  van  Kull,  midstream,  off  Sailors 

Snug  Harbor  


40  39  10 
40  39  10 
40  38  50 
40  38  50 


74  03  50 
74  03  50 
74  06  25 
74  06  25 


1 

40 
1 
40 


Ebb 
Ebb 
Ebb 
Ebb 


3.3 
3.9 
5.0 
5.0 


64 
40 
76 

56 


6.86 
6.86 
7.00 
6.86 


1.50 
2.00 


The  Narrows,  midway  between  forts . . 
The  Narrows,  midway  between  forts . . 


40  36  25 
40  36  25 


74  02  48 
74  02  48 


1 

60 


Ebb 
Flood 


3.9 
3.9 


64 
32 


7.43 
7.57 


5— EAST  RIVER,  HUDSON  RIVER,  UPPER  BAY,  KILL  VAN  KULL  AND  NARROWS.    APRIL  3,  1912 

High  water  occurred  at  Governors  Island  at  9.20  A.  M.  Low  water  at  3.50  P.  M.  The  wind  was  northwest,  with  a  velocity 
of  30  miles  per  hour. 


A.  M. 

39 

8.50 

East  river,  midstream,  at  Brooklyn 

40  42  20 

73  59  48 

1 

Flood 

6.1 

72 

6.71 

82 

40 

9.00 

East  river,  midstream,  at  Brooklyn 

Bridge  

40  42  20 

73  59  48 

30 

Flood 

6.1 

68 

6.57 

81 

41 

9.30 

Hudson  river,  midstream,  off  Pier  A . . 

40  42  19 

74  01  34 

1 

Ebb 

5.6 

88 

7.43 

85 

42 

9.40 

Hudson  river,  midstream,  off  Pier  A . . 

40  42  19 

74  01  34 

30 

Flood 

6.1 

68 

6.80 

83 

43 

10.05 

Upper  bay,  near  Robbins  Reef  bell 

40  39  10 

74  03  50 

1 

Flood 

6.1 

64 

7.28 

90 

44 

10.15 

Upper  bay,  near  Robbins  Reef  bell 

buoy  

40  39  10 

74  03  50 

40 

Flood 

6.1 

44 

7.00 

90 

45 

10.30 

Kill  van  Kull,  off  Sailors  Snug  Harbor . 

40  38  50 

74  06  25 

1 

Flood 

6.1 

64 

7.00 

87 

46 

10.40 

Kill  van  Kull,  off  Sailors  Snug  Harbor . 

40  38  50 

74  06  25 

40 

Flood 

6.1 

52 

6.86 

87 

47 

11.00 

Narrows,  midway  between  forts  

40  36  25 

74  02  48 

1 

Flood 

6.1 

56 

7.71 

97 

48 

11.10 

Narrows,  midway  between  forts  

40  36  25 

74  02  48 

60 

Flood 

6.1 

40 

7.57 

98 

DISSOLVED  OXYGEN  IN  THE  WATER  659 
TABLE  CXX— Continued 


6— EAST  RIVER,  HUDSON  RIVER,  UPPER  BAY,  KILL  VAN  KULL  AND  NARROWS.  APRIL  3,  1912- Continued. 


Sample 

"NT  — 

JNo. 

Hour 
r.  M. 

Location  of  Samples 

Feet 
below 
surface 

Tidal 
current 

Temp, 
water 
Deg.  C. 

Per 
cent, 
land 
water 

Ox} 

C.  C. 
per 
litre 

'gen 

Per 
cent, 
satura- 
tion 

Approximate 

Latitude 

Longitude 

49 
50 
51 
52 

3.50 
4.00 
4.30 
4.40 

Narrows,  midway  between  forts  

Kill  van  Kull,  off  Sailors  Snug  Harbor . 
Kill  van  Kull,  off  Sailors  Snug  Harbor . 

O       /  V 

40  36  25 
40  36  25 
40  38  50 
40  38  50 

O        /  V 

74  02  48 
74  02  48 
74  06  25 
74  06  25 

1 

60 
1 
40 

Ebb 
•hob 
Ebb 
Ebb 

6.1 

6 . 1 
6.1 
6.1 

84 

68 
80 
68 

7.43 
7. 14 
7.28 
7.00 

88 
87 
86 
85 

53 
54 
55 
56 

4.50 
5.00 
5.20 
5.30 

Upper  bay,  near  Robbins  Reef  bell  buoy 
Upper  bay,  near  Robbins  Reef  bell  buoy 
Hudson  river,  midstream,  off  Pier  A .  . 
Hudson  river,  midstream,  off  Pier  A .  . 

40  39  10 
40  39  10 
40  42  19 
40  42  19 

74  03  50 
74  03  50 
74  01  34 
74  01  34 

1 

40 
1 

30 

Ebb 
Ebb 
Ebb 
Ebb 

6.1 
6.1 
6.1 
6.1 

84 
64 
94 
92 

7.28 
6.86 
7.57 
7.57 

86 
85 
88 
88 

57 
58 

5.50 
6.00 

East  river,  midstream,  at  Brooklyn 

Bridge  

East  river,  midstream,  at  Brooklyn 

40  42  20 
40  42  20 

73  59  48 
73  59  48 

1 

30 

Ebb 
Ebb 

6.1 
6.1 

72 
64 

6.71 
6.43 

82 
80 

6 — PASSAIC  RIVER  AT  WEST  ARLINGTON  AND  AT  NEWARK,  N.  J.    APRIL  6,  1912 

High  water  occurred  at  Governors  Island  at  11.40  A.  M.    The  wind  was  northwest,  light. 


M. 

A 

12.00 

Passaic  river,  at  Erie  R.R.  trestle,  West 

Arlington,  N.  J  

40  45  18 

74  09  55 

Surface 

Slack 

10.0 

100 

7.00 

88 

P.  M. 

B 

1.30 

Passaic  river,  about  100  yards  below 

Perm.  R.R.  passenger  bridge  

40  44  48 

74  09  56 

Surface 

Slack 

10.0 

100 

4.14 

52 

7— HUDSON  RIVER  AND  EAST  RIVER.    APRIL  16,  1912 

Low  water  occurred  at  Governors  Island  at  1.30  P.  M.    The  wind  was  northwest,  light. 


A.M. 

59 

10.30 

40  42 

16 

74  01  09 

Surface 

Ebb 

10.0 

60 

6.49 

88 

60 

11.30 

East  river,  off  end  of  Pier  4  

40  42 

01 

74  00  38 

Surface 

Ebb 

10.0 

52 

5.71 

79 

8— EAST  RD7ER,  HUDSON  RIVER,  UPPER  BAY,  KILL  VAN  KULL  AND  THE  NARROWS.    JUNE  13,  1912 

High  water  occurred  at  Governors  Island  at  7.00  P.  M.  Low  water  at  1.10  P.  M.  The  wind  was  northwest,  with  a  velocity 
of  35  miles  per  hour. 


A.  M. 

61 

10.10 

East  river,  midstream,  at  Brooklyn 

Bridge  

40  42  20 

73  59  48 

1 

Ebb 

17.2 

32 

3.88 

65 

62 

10.15 

East  river,  midstream,  at  Brooklyn 

Bridge  

40  42  20 

73  59  48 

30 

Ebb 

16.7 

30 

3.88 

64 

63 

10.30 

Hudson   river,   midstream,  opposite 

Pier  A  

40  42  19 

74  01  34 

1 

Ebb 

17.2 

40 

4.49 

74 

64 

10.40 

Hudson   river,    midstream,  opposite 

Pier  A  

40  42  19 

74  01  34 

30 

Ebb 

17.2 

38 

4.39 

74 

65 

11.15 

Upper  bay,  near  Robbins  Reef  bell 

40  39  10 

74  03  50 

1 

Ebb 

17.2 

32 

4.19 

70 

66 

11.20 

Upper  bay,  near  Robbins  Reef  bell 

40  39  10 

74  03  50 

40 

Ebb 

16.7 

30 

4.19 

69 

67 

11.30 

Kill  van  Kull,  off  Sailors  Snug  Harbor . 

40  38  50 

74  06  25 

1 

Ebb 

17.2 

40 

4.29 

70 

68 

11.35 

Kill  van  Kull,  off  Sailors  Snug  Harbor . 

40  38  50 

74  06  25 

40 

Ebb 

17.2 

40 

4.29 

70 

69 

11.55 

Narrows,  midway  between  forts  

40  36  25 

74  02  48 

1 

Ebb 

17.2 

32 

4.29 

71 

70 

12.00 

Narrows,  midway  between  forts  

40  36  25 

74  02  48 

60 

Ebb 

16.7 

30 

4.39 

73 

660  DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

TABLE  CXX— Continued 


9— THE  NARROWS,  KILL  VAN  KULL,  UPPER  BAY,  HUDSON  RIVER  AND  EAST  RIVER.    JUNE  13,  1912 


Sample 
No. 

Hour 
P.  M. 

Location  of  Samples 

Feet 
below 
surface 

Tidal 
current 

Temp, 
water 
Deg.  C. 

Per 

cent, 
land 
water 

C.  C. 
per 
litre 

■gen 

Per 
cent, 
satura- 
tion 

Approximate 

Latitude 

Longitude 

71 

72 
73 
74 

2.30 
2.35 
3.10 
3.15 

Narrows,  midway  between  forts  

Narrows,  midway  between  forts  

Kill  van  Kull,  off  Sailors  Snug  Harbor . 
Kill  van  Kull,  off  Sailors  Snug  Harbor . 

O         1  It 

40  36  25 
40  36  25 
40  38  50 
40  38  50 

O        t  II 

74  02  48 
74  02  48 
74  06  25 
74  06  25 

1 

60 
1 
40 

Flood 
Flood 
Flood 
Flood 

17.2 
16.7 
17.2 
16.7 

32 
32 
36 
36 

4.80 
4.90 
4.39 
4.39 

80 
81 
73 
71 

75 
76 
77 
78 

3.40 
3.45 
4.10 
4.15 

Upper  bay,  near  Robbins  Reef  bell 

buoy  

Upper  bay,  near  Robbins  Reef  bell 

buoy  

Hudson   river,   midstream,  opposite 

Pier  A  

Hudson   river,    midstream,  opposite 

Pier  A  

40  39  10 
40  39  10 
40  42  19 
40  42  19 

74  03  50 
74  03  50 
74  01  34 
74  01  34 

1 

40 
1 

30 

Flood 
Flood 
Flood 
Flood 

17.2 
16.7 
17.2 
16.7 

30 
30 
38 
36 

4.29 
4.29 
4.19 
4.19 

71 
71 
69 
68 

0 
80 

4.30 
4.35 

East  river,  midstream,  at  Brooklyn 
Bridge  

East  river,  midstream,  at  Brooklyn 
Bridge  

40  42  20 
40  42  20 

73  59  48 
73  59  48 

1 

30 

Flood 
Flood 

17.2 
16.7 

34 
32 

3.68 
3.68 

60 
61 

10— EAST  RrVER,  HUDSON  RIVER,  UPPER  BAY,  KILL  VAN  KULL  AND  NARROWS.    JULY  11,  1912 

High  water  occurred  at  Governors  Island  at  5.30  P.  M.    Low  water  at  11.55  A.  M.    The  wind  was  southwest,  with  a  velocity 
of  10  miles  per  hour. 

81 

82 

83 
84 

A.  M. 
9.00 

9.10 

9.30 
9.40 

East  river,  midstream,  at  Brooklyn 
Bridge  

East  river,  midstream,  at  Brooklyn 
Bridge  

Hudson  river,  midstream,  off  Pier  A .  . 

Hudson  river,  midstream,  off  Pier  A .  . 

40  42  20 

40  42  20 
40  42  19 
40  42  19 

73  59  48 

73  59  48 

74  01  34 
74  01  34 

1 

30 
1 
30 

Ebb 

Ebb 
Ebb 
Ebb 

23.6 

23.6 
23.9 
23.6 

24 

24 
36 
36 

2.40 

2.40 
2.90 
2.80 

46 

46 
54 
52 

85 
86 

87 

88 

10.10 

10.15 

10.30 
10.40 

Upper  bay,  near  Robbins  Reef  bell 
buoy  

Upper  bay,  near  Robbins  Reef  bell 
buoy  

Kill  van  Kull,  off  Sailors  Snug  Harbor . 

Kill  van  Kull,  off  Sailors  Snug  Harbor . 

40  39  10 

40  39  10 

40  38  50 
40  38  50 

74  03  50 

74  03  50 
74  06  25 
74  06  25 

1 

40 
1 

40 

Ebb 

Ebb 
Ebb 
Ebb 

23.9 

23.6 
23.9 
23.9 

26 

26 
30 
30 

3.00 

3.10 
3.10 
3.10 

57 

59 
58 
58 

89 
90 

91 

92 

11.15 
11.25 
P.  M. 
1.30 
1.35 

The  Narrows,  midway  between  forts. . 
The  Narrows,  midway  between  forts . . 

The  Narrows,  midway  between  forts. . 
The  Narrows,  midway  between  forts . . 

40  36  25 
40  36  25 

40  36  25 
40  36  25 

74  02  48 
74  02  48 

74  02  48 
74  02  48 

1 

60 

1 

60 

Ebb 
Ebb 

Flood 
Flood 

23.9 
23.6 

23.9 
23.6 

26 
24 

22 
22 

3.20 
3.30 

3.90 
4.00 

61 

63 

75 
77 

93 
94 
95 

96 

2.00 
2.05 
2.30 

2.35 

Kill  van  Kull,  off  Sailors  Snug  Harbor . 
Kill  van  Kull,  off  Sailors  Snug  Harbor. 
Upper  bay,  near  Robbins  Reef  bell 

buoy  

Upper  bay,  near  Robbins  Reef  bell 

buoy  

40  38  50 
40  38  50 

40  39  10 

40  39  10 

74  06  25 
74  06  25 

74  03  50 

74  03  50 

1 
40 

1 

40 

Flood 
Flood 

Flood 

Flood 

23.9 
23.9 

23.9 

23.6 

26 
26 

24 

24 

3.20 
3.20 

3.50 

3.50 

61 
61 

67 

67 

97 

98 
99 

100 

3.05 
3.10 
3.30 

3.35 

Hudson  river,  midstream,  off  Pier  A. . 
Hudson  river,  midstream,  off  Pier  A .  . 
East  river,  midstream,  at  Brooklyn 

Bridge  

East  river,  midstream,  at  Brooklyn 

Bridge  

40  42  19 
40  42  19 

40  42  20 

40  42  20 

74  01  34 
74  01  34 

73  59  48 

73  59  48 

1 

30 

1 

30 

Flood 
Flood 

Flood 

Flood 

23.9 
23.9 

23.9 

23.9 

26 
26 

24 

24 

3.00 
3.10 

2.60 

2.60 

57 
59 

50 

50 

DISSOLVED  OXYGEN  IN  THE  WATER 


661 


TABLE  CXX— Continued 

11— EAST  RIVER ,  HUDSON  RIVER,  UPPER  BAY,  KILL  VAN  KULL  AND  NARROWS.    JULY  24,  1912 


High  water  occurred  at  Governors  Island  at  5.30  P.  M.  Low  water  at  10.40  A.  M.  The  wind  was  northwest,  with  a  velocity 
of  10  miles  per  hour. 


Sample 
No. 

Hour 
A.M. 

Location  of  Samples 

Feet 
below 
surface 

Tidal 
current 

Temp, 
water 
Deg.  C. 

Per 
cent, 
land 
water 

Ox; 

C.  C. 
per 
litre 

fgen 

Per 
cent, 
satura- 
tion 

Approximate 

Latitude 

Longitude 

101 

102 

103 
104 

9.30 

9.35 

10.00 
10.05 

East  river,  midstream,  at  Brooklyn 
Bridge  

East  river,  midstream,  at  Brooklyn 
Bridge  

Hudson  river,  midstream,  off  Pier  A . . 

Hudson  river,  midstream,  off  Pier  A .  . 

0      /  » 

40  42  20 

40  42  20 
40  42  19 
40  42  19 

Q         1  * 

73  59  48 

73  59  48 

74  01  34 
74  01  34 

1 

30 
1 
30 

Ebb 

Ebb 
Ebb 
Ebb 

21.7 

21.7 
21.7 
21.7 

22 

22 
34 
30 

2.50 

2.50 
3.10 
3.00 

46 

46 
55 
55 

105 

106 

107 
108 

10.35 

10.40 

11.15 
11.20 

Upper  bay,  near  Robbins  Reef  bell 
buoy  

Upper  bay,  near  Robbins  Reef  bell 
buoy  

Kill  van  Kull,  off  Sailors  Snug  Harbor . 

Y\  ill  tjon   Yi  nil    ^|T  Sotl^vya  Kmirr  H  afKAi. 
XV1U  Will  JA.U11,  Ull  O.LllOl  y  OIlUg  11. LI  UOl  . 

40  39  10 

40  39  10 
40  38  50 

4.0  38  KC\ 
1U  oo  uu 

74  03  50 

74  03  50 
74  06  25 

74.  fifi  9^ 

1 

40 
1 

40 

Ebb 

Ebb 
Ebb 
Ebb 

21.7 

21.7 
21.7 
21.7 

24 

24 
32 
32 

2.90 

2.90 
3.40 
3.30 

53 

53 
61 
60 

109 
110 

111 
112 

11.45 
11.50 
P.M. 
1.50 
1.55 

The  Narrows,  midway  between  forts . . 
The  Narrows,  midway  between  forts. . 

The  Narrows,  midway  between  forts . . 
The  Narrows,  midway  between  forts . . 

40  36  25 
40  36  25 

40  36  25 
40  36  25 

74  02  48 
74  02  48 

74  02  48 
74  02  48 

1 

60 

1 

60 

Ebb 
Ebb 

Flood 
Flood 

21.7 
21.7 

21.7 
21.1 

22 
20 

20 
18 

3.40 
3.40 

3.90 
4.00 

62 
62 

71 
73 

113 
114 
115 

116 

2.25 
2.30 
2.50 

2.55 

Kill  van  Kull,  off  Sailors  Snug  Harbor . 
Kill  van  Kull,  off  Sailors  Snug  Harbor . 
Upper  bay,  near  Robbins  Reef  bell 

Upper  bay,  near  Robbins  Reef  bell 
buoy  

40  38  50 
40  38  50 

40  39  10 

40  39  10 

74  06  25 
74  06  25 

74  03  50 

74  03  50 

1 

40 
1 
40 

Flood 
Flood 

Flood 

Flood 

21.7 
21.7 

21.7 

21.1 

24 
24 

22 

22 

3.80 
3.80 

3.60 

3.70 

69 
69 

65 

67 

117 
118 
119 

120 

3.15 
3.20 
3.40 

3.45 

Hudson  river,  midstream,  off  Pier  A .  . 
Hudson  river,  midstream,  off  Pier  A . . 
East  river,  midstream,  at  Brooklyn 

East  river,  midstream,  at  Brooklyn 

40  42  19 
40  42  19 

40  42  20 

40  42  20 

74  01  34 
74  01  34 

73  59  48 

73  59  48 

1 

30 

1 

30 

Ebb 
Flood 

Flood 

Flood 

21.7 
21.1 

21.7 

21.1 

34 
26 

30 

24 

3.70 
3.70 

2.80 

2.80 

66 
67 

50 

51 

12— GOWANUS  CANAL  AND  DEGRAW  STREET  SLIP,  BROOKLYN.    AUGUST  13,  1912 

High  water  occurred  at  Governors  Island  at  8.30  A.  M.    Low  water  at  3.00  P.  M.    The  wind  was  south,  light. 

121 
122 

123 

A.  M. 
11.00 
11.45 

P.M. 
12.30 

Slip  at  foot  of  Degraw  St.,  Brooklyn. . 
Gowanus  canal  at  Hamilton  avenue 

Gowanus  canal,  at  head  of  canal,  foot 
of  Douglas  street,  at  pumping  station 

40  41  13 
40  40  17 

40  40  55 

74  00  25 
73  59  56 

73  59  15 

Surface 
Surface 

Surface 

Ebb 
Flood 

Slack 

25.0 
25.0 

26.7 

28 
20 

72 

0.40 
1.80 

0.00 

8 
35 

0 

124 
125 
126 

1.00 
1.30 
2.00 

Gowanus  canal  at  Union  street  bridge. 

Slip  just  east  of  Degraw  street  slip  

Slip  at  foot  of  Degraw  street,  Brooklyn 

40  40  25 
40  41  16 
40  41  13 

73  59  50 

74  00  30 
74  00  25 

Surface 
Surface 
Surface 

Flood 
Ebb 
Ebb 

26.7 
25.6 
25.6 

28 
24 
28 

0.00 
1.20 
0.20 

0 
23 
4 

13— SLD?S  IN  HUDSON  RD7ER  AND  IN  HARLEM  RIVER.    AUGUST  16,  1912 

High  water  occurred  at  Governors  Island  at  11.20  A.  M.    Low  water  at  6.00  P.  M.    The  wind  was  northwest,  light. 

127 
128 

M. 
12.00 

P.M. 
12.45 

Slip  south  of  pier  foot  of  East  109th 
Slip  south  of  pier  foot  of  West  129th 

40  47  24 
40  49  04 

73  56  11 
73  57  43 

Surface 
Surface 

Flood 
Flood 

23.3 
23.3 

24 
40 

0.50 
2.00 

9 

36 

662  DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

TABLE  CXX— Continued 


13— SLIPS  IN  HUDSON  RIVER  AND  IN  HARLEM  RIVER.   AUGUST  16,  1912— Continued 


Sample 
No. 

Hour 
P.  M. 

Location  of  Samples 

Feet 
below 
surface 

Tidal 
current 

Temp, 
water 
Deg.  C. 

Per 

cent, 
land 
water 

Oxj 

C.  C. 
per 
litre 

'gen 

Per 
cent, 
satura- 
tion 

Approximate 

Latitude 

Longitude 

129 
130 

1.30 
2.00 

Slip  south  of  pier  foot  of  West  41st 
street,  Hudson  river  

Slip  north  of  pier  foot  of  West  34th 
street,  Hudson  river  

o     /  r 

40  45  40 
40  45  25 

Of* 

74  00  08 
74  00  23 

Surface 
Surface 

Ebb 
Ebb 

23.6 
23.6 

36 
34 

1.80 
1.60 

33 
30 

131 
132 

2.35 
3.00 

Slip  foot  of  Gansevoort  street,  Hudson 

river  

Slip  foot  of  Canal  street,  Hudson  river 

40  44  19 
40  43  34 

74  00  40 
74  00  43 

Surface 
Surface 

Ebb 
Ebb 

23.3 
23.6 

32 
32 

1.90 
1.40 

35 
26 

14— CROSS-SECTION  OF  HUDSON  RIVER  AT  PIER  A.    SEPTEMBER  13,  1912 

High  water  occurred  at  Governors  Island  at  10.00  A.  M.    Low  water  at  4.15  P.  M.    The  wind  was  south,  light. 

133 
134 

136 

A.M. 
9.25 
9.27 

Q  30 

9.35 

200  feet  off  Pier  A,  Manhattan  

200  feet  off  Pier  A,  Manhattan  

900  fpft  nff  Pi'pr  A  Mp.nhnt.tan 

}4  way  across  

40  42  16 
40  42  16 

40  49  1fi 

t\>    °±£d  X\J 

40  42  17 

74  01  10 
74  01  10 

74  01  10 

74  01  20 

1 

20 

40 
1 

Flood 
Flood 

Flnnrl 

Flood 

21.1 
21.1 

91  1 

21.1 

26 
24 

94 

26 

3.10 
3.20 

3  90 

2.90 

56 
58 

53 

137 
138 
139 
140 

9.37 
9.40 
9.45 
9.47 

14  way  across  

Y  way  across  

40  42  17 
40  42  17 
40  42  19 
40  42  19 

74  01  20 
74  01  20 
74  01  34 
74  01  34 

20 
40 
1 
20 

Flood 
Flood 
Flood 
Flood 

21.1 
21.1 
21.1 
21.1 

24 
24 
26 
24 

3.20 
3.30 
3.00 
3.30 

58 
60 
55 
60 

141 
142 
143 
144 

9.50 
9.55 
9.57 
10.00 

Y  way  across  

Yi  way  across  

%  way  across  

40  42  19 
40  42  19 
40  42  19 
40  42  19 

74  01  34 
74  01  48 
74  01  48 
74  01  48 

40 
1 
20 
35 

Flood 
Flood 
Flood 
Flood 

21.1 
21.1 
21.1 
21.1 

24 
26 
24 
24 

3.40 
2.60 
3.30 
3.40 

62 
48 
60 
62 

145 
146 
147 

148 

10.05 

10.07 

10.10 

P.  M. 
12.40 

200  feet  off  C.  R.R.  of  N.  J.  ferry,  Com- 
munipaw  

200  feet  off  C.  R.R.  of  N.  J.  ferry,  Com- 
munipaw  

200  feet  off  C.  R.R.  of  N.  J.  ferry,  Com- 

200  feet  off  Pier  A,  Manhattan  

40  42  22 
40  42  22 
40  42  22 
40  42  16 

74  01  59 
74  01  59 
74  01  59 
74  01  10 

1 

15 

30 
1 

Flood 
Flood 
Flood 
Ebb 

21.1 
21.1 
21.1 
21.1 

28 
26 
26 
26 

2.70 
3.30 
3.40 
3.00 

50 
60 
62 
55 

149 
150 
151 
152 

12.42 
12.45 
12.50 
12.52 

200  feet  off  Pier  A,  Manhattan  

200  feet  off  Pier  A,  Manhattan  

YL  way  across  

Y  way  across  

40  42  16 
40  42  16 
40  42  17 
40  42  17 

74  01  10 
74  01  10 
74  01  20 
74  01  20 

20 
40 
1 
20 

Ebb 
Ebb 
Ebb 
Ebb 

21.1 
21.1 
21.1 
21.1 

24 
24 
26 
24 

3.30 
3.40 
2.80 
3.20 

60 
62 
51 
58 

153 
154 
155 
156 

12.55 
1.00 
1.02 
1.05 

Yi  way  across  

Yi  way  across  

Yi  way  across  

40  42  17 
40  42  19 
40  42  19 
40  42  19 

74  01  20 
74  01  34 
74  01  34 
74  01  34 

40 
1 

20 
40 

Ebb 
Ebb 
Ebb 
Ebb 

21.1 
21.1 
21.1 
21.1 

24 
26 
26 
26 

3.30 
3.00 
3.30 
3.30 

60 
55 
60 
60 

157 
158 
159 
160 

1.10 
1.12 
1.15 
1.20 

%  way  across  

200  feet  off  C.  R.R.  of  N.  J.  ferry,  Com- 
munipaw  

40  42  19 
40  42  19 
40  42  19 

40  42  22 

74  01  48 
74  01  48 
74  01  48 

74  01  59 

1 

20 
35 

1 

Ebb 
Ebb 
Ebb 

Ebb 

21.1 
21.1 
21.1 

21.1 

28 
26 
26 

28 

3.00 
3.10 
3.10 

2.90 

55 
56 
56 

53 

161 

162 

163 
164 

1.22 

1.25 

2.45 
2.47 

200  feet  off  C.  R.R.  of  N.  J.  ferry,  Com- 
munipaw  

200  feet  off  C.  R.R.  of  N.  J.  ferry,  Com- 
munipaw  

200  feet  off  Pier  A,  Manhattan  

200  feet  off  Pier  A,  Manhattan  

40  42  22 

40  42  22 
40  42  16 
40  42  16 

74  01  59 

74  01  59 
74  01  10 
74  01  10 

15 

30 
1 
20 

Ebb 

Ebb 
Ebb 
Ebb 

21.1 

21.1 
21.1 
21.1 

26 

26 
28 
26 

3.10 

3.10 
2.90 
3.10 

56 

56 
53 
56 

165 
166 

2.50 
3.00 

200  feet  off  Pier  A,  Manhattan  

40  42  16 
40  42  17 

74  01  10 
74  01  20 

40 
1 

Ebb 
Ebb 

21.1 
21.1 

26 
28 

3.10 
2.80 

56 
51 

DISSOLVED  OXYGEN  IN  THE  WATER 


663 


TABLE  CXX— Continued 


14— CROSS  SECTION  OF  HUDSON  RIVER  AT  PIER  A.    SEPTEMBER  13,  1912— Continued 


Sample 
No. 

Hour 
P.  M. 

Location  of  Samples 

Feet 
below 
surface 

Tidal 
current 

Temp, 
water 

Jjeg.  Kj. 

Per 

cent, 
land 
water 

Oxj 

C.  C. 
per 
litre 

rgen 

Per 
cent, 
satura- 
tion 

Approximate 

Latitude 

Longitude 

167 

168 
169 

3.02 
3.05 
3.10 

3  19 

o      /  r 

40  42  17 
40  42  17 
40  42  19 
40  42  19 

o      /  r 

74  01  20 
74  01  20 
74  01  34 
74  01  34 

20 
40 
1 
20 

Ebb 
Ebb 
Ebb 
Ebb 

21.1 
21.1 
21.1 
21  1 

26 
26 
28 
26 

3.10 
3.10 
2.80 
3  10 

56 
56 
51 
56 

171 
172 
173 
174 

3.15 
3.20 
3.22 
3.25 

40  42  19 
40  42  19 
40  42  19 
40  42  19 

74  01  34 
74  01  48 
74  01  48 
74  01  48 

40 
1 

20 
35 

Ebb 
Ebb 
Ebb 
Ebb 

21.1 
21.1 
21.1 
21.1 

26 
30 
28 
28 

3.20 
2.80 
3.00 
3.10 

58 
51 
55 
56 

175 
176 
177 

3.35 
3.37 
3.40 

200  feet  off  C.  R.R.  of  N.  J.  pier,  Com- 

200  feet  off  C.  R.R.  of  N.  J.  pier,  Com- 

200  feet  off  C.  R.R.  of  N.  J.  pier,  Com- 
munipaw  

40  42  22 
40  42  22 
40  42  22 

74  01  59 
74  01  59 
74  01  59 

1 

15 
30 

Ebb 
Ebb 
Ebb 

21.1 
21.1 
21.1 

30 
28 
28 

2.70 
3.00 
3.00 

50 
55 
55 

16 — CROSS  SECTION  OF  EAST  RIVER  BELOW  BROOKLYN  BRIDGE.    SEPTEMBER  26,  1912 

High  water  occurred  at  Governors  Island  at  9.15  A.  M.    Low  water  at  3.50  P.  M.    The  wind  was  east,  light. 

178 
179 
180 
181 

A.  M. 
8.10 
8.12 
8.15 
8.20 

200  feet  off  Pier  10,  New  York  

200  feet  off  Pier  10,  New  York  

200  feet  off  Pier  10,  New  York  

\i  way  across  

40  42  09 
40  42  09 
40  42  09 
40  42  07 

74  00  22 
74  00  22 
74  00  22 
74  00  17 

1 

20 
30 
1 

Flood 
Flood 
Flood 
Flood 

18.9 
18.9 
18.9 
18.9 

26 
24 
24 
26 

2.94 
3.02 
3.08 
2.74 

52 
53 
54 
48 

182 
183 
184 
185 

8.22 
8.25 
8.30 
8.32 

x/i  way  across  

way  across  

^  way  across  

40  42  07 
40  42  07 
40  42  03 
40  42  03 

74  00  17 
74  00  17 
74  00  11 
74  00  11 

20 
40 
1 
20 

Flood 
Flood 
Flood 
Flood 

18.9 
18.9 
18.9 
18.9 

24 
24 
24 
24 

2.76 
3.04 
2.84 
2.89 

48 
53 
50 
51 

186 
187 
188 
189 

8.35 
8.40 
8.42 
8.45 

3^  way  across  

%  way  across  

%  way  across  

40  42  03 
40  42  00 
40  42  00 
40  42  00 

74  00  11 
74  00  05 
74  00  05 
74  00  05 

40 
1 

20 
35 

Flood 
Flood 
Flood 
Flood 

18.9 
18.9 
18.9 
18.9 

24 
24 
24 
24 

3.00 
2.80 
2.91 
2.97 

53 
49 
51 
52 

190 
191 
192 
193 

8.50 
8.52 
8.55 
10.30 

200  feet  off  Pier  10,  Brooklyn  

200  feet  off  Pier  10,  Brooklyn  

200  feet  off  Pier  10,  Brooklyn  

200  feet  off  Pier  10,  New  York  

40  41  57 
40  41  57 
40  41  57 
40  42  09 

74  00  00 
74  00  00 
74  00  00 
74  00  22 

1 

20 
35 
1 

Flood 
Flood 
Flood 
Ebb 

18.9 
18.9 
18.9 
19.4 

24 
24 
24 
24 

2.82 
2.90 
2.88 
2.99 

49 
51 
51 

52 

194 
195 
196 
197 

10.32 
10.35 
10.40 
10.42 

200  feet  off  Pier  10,  New  Y'ork  

200  feet  off  Pier  10,  New  York  

)/i  way  across  

\i  way  across  

40  42  09 
40  42  09 
40  42  07 
40  42  07 

74  00  22 
74  00  22 
74  00  17 
74  00  17 

20 
30 
1 
20 

Ebb 
Ebb 
Ebb 
Ebb 

18.9 
18.9 
19.4 
18.9 

24 
24 
24 
24 

3.04 
3.03 
2.81 
2.85 

53 
53 
49 
50 

198 
199 
200 
201 

10.45 
10.50 
10.52 
10.55 

}/2  way  across  

40  42  07 
40  42  03 
40  42  03 
40  42  03 

74  00  17 
74  00  11 
74  00  11 
74  00  11 

40 
1 
20 
40 

Ebb 
Ebb 
Ebb 
Ebb 

18.9 
19.4 
18.9 
18.9 

24 
24 
24 
24 

3.04 
2.82 
2.90 
2.89 

53 
49 
51 
51 

202 
203 
204 
205 

11.00 
11.02 
11.05 
11.10 

%  way  across  

200  feet  off  Pier  10,  Brooklyn  

40  42  00 
40  42  00 
40  42  00 
40  41  57 

74  00  05 
74  00  05 
74  00  05 
74  00  00 

1 

20 
35 
1 

Ebb 
Ebb 
Ebb 
Ebb 

19.4 
18.9 
18.9 
19.4 

24 
24 
24 
24 

2.89 
3.01 
2.87 
2.80 

51 
52 
51 
49 

206 
207 

208 
209 
210 

11.12 
11.15 
P.  M. 
1.00 
1.02 
1.05 

200  feet  off  Pier  10,  Brooklyn  

200  feet  off  Pier  10,  Brooklyn  

200  feet  off  Pier  10,  New  York  

200  feet  off  Pier  10,  New  York  

200  feet  off  Pier  10,  New  York  

40  41  57 
40  41  57 

40  42  09 
40  42  09 
40  42  09 

74  00  00 
74  00  00 

74  00  22 
74  00  22 
74  00  22 

20 
35 

1 

20 
30 

Ebb 
Ebb 

Ebb 
Ebb 
Ebb 

18.9 
18.9 

20.0 
19.4 
19.4 

24 
24 

24 
24 
24 

2.82 
2.78 

2.39 
2.43 
2.52 

49 
49 

43 
43 
45 

664  DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

TABLE  CXX— Continued 


16 — CROSS  SECTION  OF  EAST  RIVER  BELOW  BROOKLYN  BRIDGE.    SEPTEMBER  26,  1912— Continued 


Sample 

IN  0. 

Hour 

Jr.  1VJL. 

Location  of  Samples 

Feet 
below 
surface 

Tidal 
current 

Temp, 
water 
Deg.  C. 

Per 
cent, 
land 
water 

0x3 

C.  C. 
per 
litre 

'gen 

Per 

cent, 
satura- 
tion 

Approximate 

Latitude 

Longitude 

211 
212 
213 
214 

1.10 
1.12 
1.15 
1.20 

Y  way  across  

Y  way  across   

Y  way  across  

O        #  ff 

40  42  07 
40  42  07 
40  42  07 
40  42  03 

O        t  0 

74  00  17 
74  00  17 
74  00  17 
74  00  11 

1 

20 
40 
1 

Ebb 
Ebb 
Ebb 
Ebb 

20.0 
19.4 
19.4 
20.0 

24 
24 
24 
24 

2.43 
2.36 
2.43 
2.42 

43 
42 
43 
43 

215 
216 
217 
218 

1.22 
1.25 
1.30 
1.32 

Yi  way  across  

Y  way  across  

way  across  

way  across  

40  42  03 
40  42  03 
40  42  00 
40  42  00 

74  00  11 
74  00  11 
74  00  05 
74  00  05 

20 
40 
1 
20 

Ebb 
Ebb 
Ebb 
Ebb 

19.4 
19.4 
20.0 
20.0 

24 
24 
24 
24 

2.50 
2.50 
2.40 
2.49 

45 
45 
43 
44 

219 
220 
221 
222 

1.35 
1.40 
1.42 
1.45 

%  way  across  

200  feet  off  Pier  10,  Brooklyn  

200  feet  off  Pier  10,  Brooklyn  

200  feet  off  Pier  10,  Brooklyn  

40  42  00 
40  41  57 
40  41  57 
40  41  57 

74  00  05 
74  00  00 
74  00  00 
74  00  00 

35 
1 
20 
35 

Ebb 
Ebb 
Ebb 
Ebb 

19.4 
20.0 
20.0 
20.0 

24 
24 
24 
24 

2.48 
2.40 
2.42 
2.40 

44 
43 
43 
43 

16— CROSS  SECTION  OF  THE  NARROWS.    OCTOBER  4,  1912 
High  water  occurred  at  Governors  Island  at  2.35  P.  M.    Low  water  at  9.50  A.  M.    The  wind  was  southwest,  moderate. 

223 
224 
225 
226 

A.  M. 
8.00 
8.02 
8.05 
8.10 

200  feet  off  Fort  Lafayette  

200  feet  off  Fort  Lafayette  

200  feet  off  Fort  Lafayette  

Y  way  across  

40  36  29 
40  36  29 
40  36  29 
40  36  27 

74  02  24 
74  02  24 
74  02  24 
74  02  34 

1 

20 
40 
1 

Ebb 
Ebb 
Ebb 
Ebb 

17.2 
17.2 
17.2 
17.2 

26 
24 
24 
26 

4.42 
4.60 
4.70 
4.40 

75 
78 
80 
75 

227 
228 
229 
230 

8.12 
8.15 
8.20 
8.22 

Y  way  across  

Y  way  across  

Yl  way  across  

Y  way  across  

40  36  27 
40  36  27 
40  36  25 
40  36  25 

74  02  34 
74  02  34 
74  02  48 
74  02  48 

30 
60 
1 
30 

Ebb 
Ebb 
Ebb 
Ebb 

17.2 
17.2 
17.2 
17.2 

24 
24 
26 
24 

4.57 
4.70 
4.42 
4.54 

77 
80 
75 
77 

231 

232 
233 
234 

8.25 
8.30 
8.32 
8.35 

Yi  way  across  

%  way  across  

3/i  way  across  

%  way  across  

40  36  25 
40  36  23 
40  36  23 
40  36  23 

74  02  48 
74  03  02 
74  03  02 
74  03  02 

60 
1 
30 
60 

Ebb 
Ebb 
Ebb 
Ebb 

17.2 
17.2 
17.2 
17.2 

24 
26 
24 
24 

4.74 
4.35 
4.40 
4.48 

80 
74 
75 
76 

235 
236 
237 
238 

8.40 
8.42 
8.45 
10.30 

200  feet  off  Fort  Wadsworth  

200  feet  off  Fort  Wadsworth  

200  feet  off  Fort  Wadsworth  

200  feet  off  Fort  Lafayette  

40  36  21 
40  36  21 
40  36  21 
40  36  29 

74  03  12 
74  03  12 
74  03  12 
74  02  24 

1 

30 
60 
1 

Ebb 
Ebb 
Ebb 
Slack 

17.2 
17.2 
17.2 
17.2 

26 
24 
24 
26 

4.18 
4.40 
4.47 
4.02 

71 

75 
76 
68 

239 
240 
241 
242 

10.32 
10.35 
10.40 
10.42 

200  feet  off  Fort  Lafayette  

200  feet  off  Fort  Lafayette  

Y  way  across  

Y  way  across  

40  36  29 
40  36  29 
40  36  27 
40  36  27 

74  02  24 
74  02  24 
74  02  34 
74  02  34 

20 
40 
1 
30 

1st  Flood 
1st  Flood 
Slack 
Flood 

17.5 
17.5 
17.2 
17.5 

24 
24 
26 
24 

4.20 
4.20 
4.00 
4.37 

71 
71 
68 
74 

243 
244 
245 
246 

10.45 
10.50 
10.52 
10.55 

Y  way  across  

Yi  way  across  

Y  way  across  

Yi  way  across  

40  36  27 
40  36  25 
40  36  25 
40  36  25 

74  03  34 
74  02  48 
74  02  48 
74  02  48 

60 
1 
30 
60 

Flood 
Slack 
Flood 
Flood 

17.5 
17.2 
17.5 
17.5 

24 
24 
22 
22 

4.60 
4.12 
4.62 
4.74 

78 
70 
78 
80 

247 
248 
249 
250 
251 

11.00 
11.02 
11.05 
11.10 
11.12 

Y  way  across  

Y  way  across  

Y  way  across  

200  feet  off  Fort  Wadsworth  

200  feet  off  Fort  Wadsworth  

40  36  23 
40  36  23 
40  36  23 
40  36  21 
40  36  21 

74  02  03 
74  02  03 
74  02  03 
74  03  12 
74  03  12 

1 

30 
60 
1 
30 

Slack 
Flood 
Flood 
Slack 
Flood 

17.2 
17.8 
17.8 
17.2 
17.8 

24 
22 
22 
24 
22 

4.18 
4.90 
4.88 
4.18 
4.87 

71 
84 
84 
71 
84 

252 
253 
254 
255 
256 

11.15 
1.15 
1.17 
1.20 
1.25 

200  feet  off  Fort  Wadsworth  

200  feet  off  Fort  Lafayette  

200  feet  off  Fort  Lafayette  

200  feet  off  Fort  Lafayette  

Y  way  across  

40  36  21 
40  36  29 
40  36  29 
40  36  29 
40  36  27 

74  03  12 
74  02  24 
74  02  24 
74  02  24 
74  02  34 

60 
1 
20 
40 
1 

Flood 
Flood 
Flood 
Flood 
Flood 

17.8 
17.8 
17.8 
17.8 
17.8 

22 
24 
22 
22 
24 

4.90 
5.02 
5.30 
5.30 
5.00 

84 
87 
91 
91 
87 

DISSOLVED  OXYGEN  IN  THE  WATER 


665 


TABLE  CXX— Continued 


16— CROSS  SECTION  OF  THE  NARROWS.    OCTOBER  4,  1912— Continued 


Sample 
No. 

Hour 
P.  M. 

Location  of  Samples 

Feet 
below 
surface 

Tidal 
current 

Temp, 
water 
Deg.  C. 

Per 
cent, 
land 
water 

Ox 

C.  C. 
per 
litre 

ygen 

Per 
cent, 
satura- 
tion 

Approximate 

Latitude 

Longitude 

OCT 

258 
259 
260 

1.30 
1.35 
1.37 

Yi  way  across  

Y2  way  across  

0    /  9 

40  36  27 
40  36  27 
40  36  25 
40  36  25 

0      /  w 

74  02  34 
74  02  34 
74  02  48 
74  02  48 

60 
1 
30 

r  iuuq 

Flood 
Flood 
Flood 

17  8 
1/  .0 

17.8 
17.8 
17.8 

99 
22 
24 
22 

e.  97 

5.30 
5.12 
5.44 

Q1 

y  1 
91 

88 
94 

261 
262 
263 
264 

1.40 
1.45 
1.47 
1.50 

Yi  way  across  

%  way  across  

%  way  across  

40  36  25 
40  36  23 
40  36  23 
40  36  23 

74  02  48 
74  03  02 
74  03  02 
74  03  02 

60 
1 
30 
60 

Flood 
Flood 
Flood 
Flood 

17.8 
17.8 
17.8 
17.8 

22 
24 
22 
22 

5.44 
5.08 
5.38 
5.40 

94 
88 
93 
93 

265 
266 
267 

1.55 
1.57 
2.00 

200  feet  off  Fort  Wadsworth  

200  feet  off  Fort  Wadsworth  

200  feet  off  Fort  Wadsworth  

40  36  21 
40  36  21 
40  36  21 

74  03  12 
74  03  12 
74  03  12 

1 

30 
60 

Flood 
Flood 
Flood 

17.8 
17.8 
17.8 

24 
22 
22 

5.08 
5.37 
5.40 

88 
93 
93 

17— CROSS  SECTION  OF  EAST  RIVER  BELOW  BROOKLYN  BRIDGE.    NOVEMBER  26,  1912 

High  water  occurred  at  Governors  Island  at  10.00  A.  M.    Low  water  at  4.10  P.  M.    The  wind  was  northwest,  with  a  velocity 
of  20  miles  per  hour. 

268 
269 
270 
271 

A.  M. 
8.40 
8.42 
8.45 
8.50 

200  feet  off  Pier  10,  New  York  

200  feet  off  Pier  10,  New  York  

200  feet  off  Pier  10,  New  York  

way  across  

40  42  09 
40  42  09 
40  42  09 
40  42  07 

74  00  22 
74  00  22 
74  00  22 
74  00  17 

1 
20 
30 

1 

Flood 
Flood 
Flood 
Flood 

8.3 
8.9 
8.9 
8.3 

44 
40 
40 
44 

5.40 
5.60 
5.60 
5.40 

73 
77 
77 
73 

272 
273 
274 
275 

8.52 
8.55 
9.00 
9.02 

\i  way  across  

34  way  across  

Y2  way  across  

H  way  across  

40  42  07 
40  42  07 
40  42  03 
40  42  03 

74  00  17 
74  00  17 
74  00  11 
74  00  11 

20 
40 
1 

20 

Flood 
Flood 
Flood 
Flood 

8.9 
8.9 
8.3 
8.9 

40 
40 
44 
40 

5.60 
5.60 
5.50 
5.60 

77 
77 
75 
77 

276 
277 
278 
279 

9.05 
9.10 
9.12 
9.15 

Y2  way  across  

%  way  across  

%  way  across  

%  way  across  

40  42  03 
40  42  00 
40  42  00 
40  42  00 

74  00  11 
74  00  05 
74  00  05 
74  00  05 

40 
1 

20 
35 

Flood 
Flood 
Flood 
Flood 

8.9 
8.3 
8.9 
8.9 

40 
42 

38 
38 

5.60 
5.20 
5.50 
5.50 

77 
71 
76 
76 

280 
281 
282 
283 

284 
285 
286 

9.20 
9.22 
9.25 
11.00 

11.02 
11.05 
11.10 

200  feet  off  Pier  10,  Brooklyn  

200  feet  off  Pier  10,  Brooklyn  

200  feet  off  Pier  10,  Brooklyn  

200  feet  off  Pier  10,  New  York  

200  feet  off  Pier  10,  New  York  

200  feet  off  Pier  10,  New  York  

Y\  way  across  

40  41  57 
40  41  57 
40  41  57 
40  42  09 

40  42  09 
40  42  09 
40  42  07 

74  00  00 
74  00  00 
74  00  00 
74  00  22 

74  00  22 
74  00  22 
74  00  17 

1 

20 
35 
1 

20 
30 
1 

Flood 
Flood 
Flood 
Begin- 
ning Ebb 

Ebb 

Ebb 

Ebb 

8.3 
8.9 
8.9 

8.3 
8.9 
8.9 
8.3 

42 

38 
38 

40 
40 
40 
40 

5.10 
5.30 
5.40 

5.10 
5.20 
5.20 
5.10 

70 
73 
74 

70 
72 
72 
70 

287 
288 
289 
290 

11.12 
11.15 
11.20 
11.22 

]4  way  across  

Yi  way  across  

40  42  07 
40  42  07 
40  42  03 
40  42  03 

74  00  17 
74  00  17 
74  00  11 
74  00  11 

20 
40 
1 

20 

Ebb 
Ebb 
Ebb 
Ebb 

8.9 
8.9 
8.3 
8.9 

40 
40 
40 
40 

5.20 
5.20 
5.20 
5.20 

72 
72 
71 
72 

291 
292 
293 
294 

11.25 
11.30 
11.32 
11.35 

Yi  way  across  

%  way  across  

%  way  across  

%  way  across  

40  42  03 
40  42  00 
40  42  00 
40  42  00 

74  00  11 
74  00  05 
74  00  05 
74  00  05 

40 
1 

20 
35 

Ebb 
Ebb 
Ebb 
Ebb 

8.9 

8.3 
8.9 
8.9 

40 
40 
38 
38 

5.20 
5.00 
5.10 
5.10 

72 
68 
70 
70 

295 
296 
297 

11.40 
11.42 
11.45 

200  feet  off  Pier  10,  Brooklyn  

200  feet  off  Pier  10,  Brooklyn  

200  feet  off  Pier  10,  Brooklyn  

40  41  57 
40  41  57 
40  41  57 

74  00  00 
74  00  00 
74  00  00 

1 

20 
35 

Ebb 
Ebb 
Ebb 

8.3 
8.9 
8.9 

40 
38 
38 

5.00 
5.10 
5.10 

68 
70 
70 

666  DATA  RELATING  TO  THE  PR  OTECTION  OF  THE  HARBOR 

TABLE  CXX— Continued 


17— CROSS  SECTION  OF  EAST  RIVER  BELOW  BROOKLYN  BRIDGE.    NOVEMBER  26,  1912— Continued. 


Sample 
No. 

Hour 
P.  M. 

Location  of  Samples 

Feet 
below 
surface 

Tidal 
current 

Temp, 
water 

ueg.  Kj. 

Per 

cent, 
land 
water 

C.  C. 
per 
litre 

rgen 

Per 
cent, 
satura- 
tion 

Approximate 

Latitude 

Longitude 

298 
299 
300 
301 

2.25 
2.28 
2.30 
2.34 

200  feet  off  Pier  10  New  York 

200  feet  off  Pier  10,  New  York  

200  feet  off  Pier  10,  New  York  

^  way  across  

O         /  If 

40  42  09 
40  42  09 
40  42  09 
40  42  07 

0      /  w 

74  00  22 
74  00  22 
74  00  22 
74  00  17 

1 

20 
30 
1 

Ebb 
Ebb 
Ebb 
Ebb 

8.9 
8.9 
8.9 
8.9 

38 
38 
38 
38 

4.80 
5.00 
5.10 
4.70 

66 
70 
71 
65 

302 
303 
304 
305 

2.36 
2.38 
2.41 
2.43 

Y.  way  across  

Y  way  across  

Yz  way  across  

Yi  way  across  

40  42  07 
40  42  07 
40  42  03 
40  42  03 

74  00  17 
74  00  17 
74  00  11 
74  00  11 

20 
40 
1 
20 

Ebb 
Ebb 
Ebb 
Ebb 

8.9 
8.9 
8.9 
8.9 

38 
38 
38 
38 

5.00 
5.00 
4.80 
5.00 

70 
70 
66 
70 

306 
307 
308 
309 

2.45 
2.48 
2.50 
2.52 

Y  way  across  

%  way  across  

Y  way  across  

40  42  03 
40  42  00 
40  42  00 
40  42  00 

74  00  11 
74  00  05 
74  00  05 
74  00  05 

40 
1 

20 
35 

Ebb 
Ebb 
Ebb 
Ebb 

8.9 
8.9 
8.9 
8.9 

38 
38 
38 
38 

5.00 
4.80 
5.00 
5.00 

70 
66 
70 
70 

310 
311 
312 

2.55 
2.57 
3.00 

200  feet  off  Pier  10,  Brooklyn  

200  feet  off  Pier  10,  Brooklyn  

200  feet  off  Pier  10,  Brooklyn  

40  41  57 
40  41  57 
40  41  57 

74  00  00 
74  00  00 
74  00  00 

1 

20 
35 

Ebb 
Ebb 
Ebb 

8.9 
8.9 
8.9 

38 
38 
38 

4.90 
5.00 
5.00 

68 
70 
70 

DISSOLVED  OXYGEN  IN  THE  WATER  667 

TABLE  CXXI 

Average  Volume  and  Percentage  of  Saturation  of  Dissolved  Oxygen  in  the  Water  in  the  Year  1912 

Averages  for  various  parts  of  the  harbor 


Data  for  this  table  are  contained  in  Table  CXX. 


Number 

Averages : 

Averages: 

Location 

of 

C.  C. 

per  cent. 

Samples  included  in  the  averages 

analyses 

per  litre 

saturation 

Upper  bay  

24 

5.37 

75 

7-8,  13-14,  23-24,  33-34,  43-44,  53-54,  65-66,  75-76,  85-86,  95-96, 

105-106,  115-116. 

Hudson  river  

75 

3.74 

60 

3-4,  11-12,  21-22,  31-32,  41-42,  55-56,  59,  63-64,  77-78,  83-84,  97-98, 

103-104,  117-118,  128-177. 

East  river  

115 

4.15 

62 

1-2,  9-10,  19-20,  29-30,  39-40,  57-58,  60-62,  79-82,  99-102,  119-120, 

178-222,  268-312. 

Harlem  river  

1 

0.50 

9 

127. 

Kill  van  Kull  

22 

5.22 

74 

15-16,  25-26,  35-36,  45-46,  51-52,  67-68,  73-74,  87-88,  93-94,  107-108, 

113-114. 

The  Narrows  

69 

5.10 

81 

5-6,  17-18,  27-28,  37-38,  47-50,  69-72,  89-92,  109-112,  223-267. 

Gowanus  canal  

3 

0.60 

12 

122-124. 

Buttermilk  channel. 

3 

0.60 

12 

121,  125-126. 

668 


DATA  RELATING  TO  THE  PROTECTION  OP 


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DISSOLVED  OXYGEN  IN  THE  WATER 


669 


TABLE  CXXIII 


Average  Volume  and  Percentage  of  Saturation  of  Dissolved  Oxygen  in  the  Water  in  the  Year  1912 
Average,  of  samples  taken  on  Ebb  and  Flood  Currents  for  various  parts  of  the  harbor 

Data  for  this  table  are  contained  in  Table  CXX. 


Location 


Upper  Bay  

Hudson  river  

East  river  

Harlem  river  

Kill  van  Kull  

The  Narrows  

Gowanus  canal. . . . 
Buttermilk  channel 


Currents 


Ebb  Currents 

Flood  Currents 

S3  .£ 

rj 

u  g 

X 
<—  " 
O  X 

d  g 

x  5 

OE 

Z  x 

6  £ 

.  ■  -fcj 

—  Z. 
..  aa 

.  >. 

y.  _z 

|a 

§,| 
?  1 

Samples  included  in  the  averages 

No. 
naly 

x  _z: 

c; 

tl  - 

M  — 
E  ■ 

Samples  mcluded  in  the  averages 

Pi 

>  S 

S3 

—  — 
- 

> 
< 

<  r 

> 
< 

<  - 

13 

5.35 

73 

7,  13-14,  33-34,  53-54,  65-66,  85-86, 

11 

5.40 

78 

8,  23-24,  43-44,  75-76,  95-96,  115- 

105-106. 

116. 

51 

3.76 

60 

3-4,  11-12,  31-32,  41,  55-56,  59,  63- 

24 

3.68 

61 

21-22,  42,  77-78,  97-98, 118, 128, 133- 

64,  83-84,  103-104,  117,  129-132, 

147. 

148-177. 

75 

4.09 

61 

1-2,  9-10,  29-30,  57-58,  60-62,  81-S2, 

40 

4.27 

63 

19-20-39-40.  79-80,  99-100,  119-120, 

101-102,  193-222,  283-312. 

178-192,  268-282. 

No  samples  on  ebb  current. 

1 

0.50 

9 

127  (taken  in  slip). 

12 

5.33 

74 

15-16,  35-36,  51-52,  67-68,  87-88, 

10 

5.09 

75 

25-26,  45-46,  73-74,  93-94,  113-114. 

107-108. 

32 

4.82 

75 

5, 17-18,  37,  49-50,  69-70,  89-90, 109- 

37 

5.34 

86 

6,  27-28,  38,  47-48,  71-72,  91-92, 111- 

110,  223-238,  241,  244,  247,  250. 

112,  239-240,  242-243,  245-246, 

248-249,  251-267. 

No  samples  on  ebb  current. 

3 

0.60 

12 

122-124. 

3 

0.60 

12 

121,  125-126. 

No  samples  on  flood  current. 

TABLE  CXXIV 


Average  Volume  and  Percentage  of  Saturation  of  Dissolved  Oxygen  in  the  Water  in  the  Year  1912 

Summary  of  Tables  CXXI,  CXXII  and  CXXIII 
Data  for  this  table  are  contained  in  Table  CXX. 


Depth 

s 

Currents 

All 

Depths 

and  Tides 

Surface 

Mid-depth 

Bottom 

Ebb 

Flood 

Location 

X 
C  X 

6 

O  £ 

%—  g 
-  - 

9  i: 

X 

^  ~ 

O  X 

d 

dg 

i:  per 
ration 

X 

ft  5 

d 

d  £ 

^  g 

.2 

—  C 

O  X 

d 

d| 

•_  = 
— 

QQ 

— 

d 

i:  per 
ration 

X 

•—  a 

d 

d« 

i:  per 
ration 

.  >. 

. .  ~j 

X  -^z 
- 

i  — 

.  >> 

>  >  *^ 

X  — 

i; 

O  3 
zf"= 

O  X 

r.  — 

r  ~ 

Si 

x  ~ 

t.  r 

lis 

O  x 
.  _>■■ 

-  - 

c  - 

C  x 

.  >> 

X  ^ 

a 

°  •? 

A 

*1 

tc 't 

C  ^ 

*  ;" 

C  2 

If 

z  £ 

H  s 

=s  g 

-  2 

Z 

:-  — 

o 

>  3 

h  — 

ll 

1 

£  P 

S 

-  — 

a 

> 

>  = 
<  - 

> 

<  § 

> 

•<  8 

> 

> 

^§ 

> 

•<  » 

< 

< 

< 

< 

< 

Upper  bay  

Hudson  river  

24 

5.37 

75 

12 

5.38 

75 

12 

5.35 

76 

13 

5. 35 

73 

n 

5.40 

78 

75 

3.74 

60 

33 

3.69 

58 

15 

3  17 

58 

27 

4  10 

65 

51 

3.76 

60 

24 

3  68 

61 

East  river  

115 

4.15 

62 

43 

4.18 

61 

30 

3.99 

60 

42 

4.17 

61 

75 

4.09 

61 

40 

4.27 

63 

Harlem  river  

1 

0.50 

9 

1 

0.50 

9 

1 

0.50 

9 

Kill  van  Kull  

22 

5.22 

74 

11 

5.25 

74 

11 

5.19 

74 

12 

5.33 

74 

10 

5.09 

75 

The  Narrows  

69 

5.10 

81 

27 

5.07 

79 

15 

4.82 

27 

27 

5.28 

83 

32 

4.82 

75 

37 

5.34 

86 

Gowanus  canal  

3 

0.60 

12 

3 

0.60 

12 

3 

0.60 

12 

Buttermilk  channel  

3 

0.60 

12 

3 

0.60 

12 

3 

0.60 

12 

312 


Total  number  of  analyses,  1912,  Nos.  1-312,  inclusive.   Samples  A  and  B,  taken  in 
Passaic  River,  not  included. 


Plate  B 


Percentage  of  Saturation  of 
Dissolved  Oxygen 
in  the  Water  of  New  York  Harbor 

in  1912 


DISSOLVED  OXYGEN  IN  THE  WATER 


671 


INTRODUCTION  TO  TABLES  CXXV,  CXXVI,  CXXVII,  CXXVIII,  CXXIX 

These  tables,  containing  the  results  of  analyses  for  dissolved  oxygen  made  in  the 
year  1913,  follow  the  same  plan  as  the  similar  tables  for  1911  and  1912.  In  Table  CXXV 
are  contained  the  results  of  analyses  made  in  various  parts  of  the  harbor  in  1913.  In 
Tables  CXXVI,  CXXVII  and  CXXVIII  are  shown  the  averages  of  results  from  ob- 
servations at  various  locations,  depths  and  tides,  computed  from  the  data  contained  in 
Table  CXXV.  In  Table  CXXIX  is  given  a  summary  of  the  results  of  these  calcula- 
tions. 


672 


DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


TABLE  CXXV 

VOLUME  AND  PERCENTAGE  OF  SATURATION  OF  DISSOLVED  OXYGEN  IN  THE  WATER 

IN  THE  YEAR  1913 


Table  of  Contents 


Section 
No. 


Date  of 
Collection 


Location 

1  East  river,  Hudson  river,  Upper  bay,  Kill  van  Kull  and  Narrows  Jan.  9 

2  East  river,  Hudson  river,  Upper  bay,  Kill  van  Kull  and  Narrows  Feb.  18 

3  Slips,  East  109th  street  and  West  129th  street,  Manhattan  Feb.  14 

4  Slips  of  Lower  East  river  and  Gowanus  canal  Feb.  17 

5  Slips  of  Lower  East  river  Feb.  17 

6  Slips  of  East  river  below  24th  street  Feb.  20 

7  Slips  of  Hudson  river  Feb.  20 

8  Wallabout  canal  Feb.  21 

9  Newtown  creek  Feb.  21 

10  Slips  in  Lower  East  river  Feb.  25 

11  Hudson  river  Apr.  5 

12  Narrows,  Kill  van  Kull,  Robbins  Reef,  Hudson  and  East  rivers  May  29 

13  East  river,  Hudson  river,  Robbins  Reef,  Kill  van  Kull  and  Narrows  June  11 

14  East  river  at  Brooklyn  Bridge  June  17 

15  East  river,  Cross-section  at  Pier  10  July  2 

16  Narrows,  Cross-section  between  Forts  Lafayette  and  Wadsworth  July  3 

17  East  river,  Brooklyn  Bridge  to  118th  street  July  7 

18  East  river,  Cross-section  at  Lawrence  Point  July  8 

19  Hudson  river,  Cross-section,  Pier  A  to  C.  R.R.  of  N.  J.  pier  July 

20  Robbins  Reef  July  10. 

21  Kill  van  Kull,  Cross-section  at  Sailors  Snug  Harbor  July  11 

22  East  river,  Throgs  Neck,  Cross-section  to  Cryders  Point  landing  July  14 

23  Harlem  river,  Willis  Avenue  Bridge  to  Spuyten  Duyvil  July  15 

24  Harlem  river,  Cross-section  at  Mt.  St.  Vincent  July  16 

25  Hudson  river,  Yonkers  to  Pier  A  July  17 

26  East  river,  Cross-section  at  Pier  10  July  18 

27  Narrows,  Cross-section,  Fort  Lafayette  to  Fort  Wadsworth  July  24 

28  East  river  to  the  Narrows,  midstream  July  25 

29  Harlem  river,  back  of  Wards  Island  Aug.  14 

30  East  river  at  Pier  10  Aug.  15 

31  East  river  Aug.  21 

32  East  river,  Hudson  river,  Robbins  Reef,  Kill  van  Kull  and  Narrows  Aug.  27 

33  East  river,  Hudson  river,  Robbins  Reef,  Kill  van  Kull  and  Narrows  Sept.  19 


1913. 
1913. 
1913. 
1913. 
1913. 
1913. 
1913. 
1913. 
1913. 
1913. 
1913. 
1913. 
1913. 
1913. 
1913. 
1913. 
1913. 
1913. 
1913. 
1913. 
1913. 
1913. 
1913. 
1913. 
1913. 
1913. 
1913. 
1913. 
1913. 
1913. 
1913. 
1913. 
1913. 


DISSOLVED  OXYGEN  IN  THE  WATER 


673 


TABLE  CXXV 

1— EAST  RIVER,  HUDSON  RIVER,  UPPER  BAY,  KILL  VAN  KULL  AND  NARROWS.    JANUARY  9,  1913 


High  water  occurred  at  Governors  Island  at  10.00  A.  M.  Low  water  at  4.00  P.  M.  The  wind  was  northwest,  with  a  velocity 
of  20  miles  per  hour. 


Sample 
No. 

Hour 
A.  M. 

Location  of  Samples 

Feet 
below 
surface 

Tidal 
current 

Temp, 
water 
Deg.  C. 

Per 
cent, 
land 
water 

Oxj 

C.  C. 
per 
litre 

rgen 

Per 
cent, 
satura- 
tion 

Approximate 

Latitude 

Longitude 

313 

314 

315 
316 

7.45 

7.47 

8.00 
8.03 

East  river,  midstream,  at  Brooklyn 

East  river,  midstream,  at  Brooklyn 

Bridge  

Hudson  river,  midstream,  off  Pier  A.  . 
Hudson  river,  midstream,  off  Pier  A.  . 

o     /  ar 

40  42  20 

40  42  20 
40  42  19 
40  42  19 

O       /  M 

73  59  48 

73  59  48 

74  01  34 
74  01  34 

1 

30 
1 
30 

Flood 

Flood 
Flood 
Flood 

2.8 

3.3 
2.8 
3.3 

64 

64 
72 
72 

6.00 

6.00 
6.20 
6.00 

68 

70 
70 
70 

317 
318 
319 
320 

8.23 
8.25 
8.40 
8.43 

Upper  bay,  at  Robbins  Reef  bell  buoy . 

T    r-\  rx  i^r'  \~\  n  x  r     nt    Y<  / .     limp    Vt  a£tl    r\o  1  1  hllftv 

upper  uity,  at  xvuuuiiio  rveei  ueii  uuuj  . 
Kill  van  Kull,  off  Sailors  Snug  Harbor . 
Kill  van  Kull,  off  Sailors  Snug  Harbor. 

40  39  15 

40  QQ  K 

OJ  Id 

40  38  50 
40  38  50 

74  03  50 

74  03  "iO 

74  06  07 
74  06  07 

1 

40 
1 
30 

Flood 
Flood 
Flood 
Flood 

2.8 
3.3 
2.8 
3.3 

60 
60 
60 
60 

6.30 
6.40 
6.10 
6.20 

72 
74 
70 
71 

321 
322 
323 

324 

9.06 
9.09 
11  20 

11.23 

The  Narrows,  midway  between  forts . . 
The  Narrows,  midway  between  forts . . 
East  river,  midstream,  at  Brooklyn 

Bridge  

East  river,  midstream,  at  Brooklyn 

Bridge  

40  36  25 
40  36  25 

40  42  20 

40  42  20 

74  02  48 
74  02  48 

73  59  48 

73  59  48 

1 

60 

1 

30 

Flood 
Flood 

Ebb 

Ebb 

3.9 
3.9 

3.3 

3.3 

52 
52 

64 

64 

6.80 
6.80 

5.60 

5.60 

82 
82 

65 

65 

325 
326 

327 
328 

11.40 
11.43 
P.  M. 
12.15 
12.18 

Hudson  river,  midstream,  off  Pier  A .  . 
Hudson  river,  midstream,  off  Pier  A .  . 

Upper  bay,  at  Robbins  Reef  bell  buoy . 
Upper  bay,  at  Robbins  Reef  bell  buoy . 

40  42  19 
40  42  19 

40  39  15 
40  39  15 

74  01  34 
74  01  34 

74  03  50 
74  03  50 

1 

30 

1 

40 

Ebb 
Ebb 

Ebb 
Ebb 

3.3 
3.3 

3.3 
3.3 

72 
72 

66 
56 

5.70 
5.70 

6.00 
6.00 

65 
65 

70 
70 

329 
330 
331 
332 

12.40 
12.45 
1.30 
1.35 

Kill  van  Kull,  off  Sailors  Snug  Harbor . 
Kill  van  Kull,  off  Sailors  Snug  Harbor . 
The  Narrows,  midway  between  forts. . 
The  Narrows,  midway  between  forts. . 

40  38  50 
40  38  50 
40  36  25 
40  36  25 

74  06  07 
74  06  07 
74  02  48 
74  02  48 

1 

30 
1 
60 

Ebb 
Ebb 
Ebb 
Ebb 

3.3 
3.3 
3.3 
3.3 

64 
64 
56 
56 

6.00 
6.00 
6.10 
6.10 

70 
70 
71 
71 

2— EAST  RIVER,  HUDSON  RIVER,  UPPER  BAY,  KILL  VAN  KULL  AND  THE  NARROWS.    FEBRUARY  18,  1913 

High  water  occurred  at  Governors  Island  at  6.15  P.  M.    Low  water  at  12.50  P.  M.    The  wind  was  northwest,  with  a  velocity 
of  30  miles  per  hour. 

333 

334 

335 
336 

A.  M. 
10.00 

10.05 

10.30 
10.35 

East  river,  midstream,  at  Brooklyn 
Bridge  

East  river,  midstream,  at  Brooklyn 
Bridge  

Hudson  river,  midstream,  off  Pier  A.  . 

Hudson  river,  midstream,  off  Pier  A.  . 

40  42  20 

40  42  20 
40  42  19 
40  42  19 

73  59  48 

73  59  48 

74  01  34 
74  01  34 

1 

30 
1 
30 

Ebb 

Ebb 
Ebb 
Ebb 

1.7 

1.7 
1.7 
1.7 

30 

30 
36 
36 

5.40 

5.40 
5.80 
5.80 

62 

62 
66 
66 

337 

338 

339 
340 

11.10 

11.15 

11.30 
11.35 

Upper  bay,  near  Robbins  Reef  bell 
buoy  

Upper  bay,  near  Robbins  Reef  bell 
buoy  

Kill  van  Kull,  off  Sailors  Snug  Harbor . 

Kill  van  Kull,  off  Sailors  Snug  Harbor. 

40  39  10 

40  39  10 
40  38  50 
40  38  50 

74  03  50 

74  03  50 
74  06  07 
74  06  07 

1 

40 
1 

30 

Ebb 

Ebb 
Ebb 
Ebb 

1.7 

1.7 
1.7 
1.7 

30 

30 
40 
40 

5.90 

6.00 
5.80 
5.80 

68 

69 
65 
65 

341 

342 
343 
344 

12.00 
P.  M. 
12.05 
3.25 
3.30 

The  Narrows,  midway  between  forts . . 

The  Narrows,  midway  between  forts . . 
The  Narrows,  midway  between  forts . . 
The  Narrows,  midway  between  forts. . 

40  36  25 

40  36  25 
40  36  25 
40  36  25 

74  02  48 

74  02  48 
74  02  48 
74  02  48 

1 

60 
1 
60 

Ebb 

Ebb 
Flood 
Flood 

1.7 

1.7 

1.7 
1.7 

30 

28 
28 
24 

6.00 

6.10 
6.60 
6.70 

69 

70 
76 
78 

345 
346 
347 

4.00 
4.05 
4.20 

Kill  van  Kull,  off  Sailors  Snug  Harbor 
Kill  van  Kull,  off  Sailors  Snug  Harbor 
Upper  bay,  near  Robbins  Reef  bell 
buoy  

40  38  50 
40  38  50 

40  39  10 

74  06  07 
74  06  07' 

74  03  50 

1 

30 

1 

Flood 
Flood 

Flood 

1.7 
1.7 

1.7 

32 
30 

30 

6.20 
6.30 

6.20 

71 
72 

71 

674  DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

TABLE  CXXV— Continued 


2— EAST  RIVER,  HUDSON  RIVER,  UPPER  BAY,  KILL  VAN  KULL  AND  NARROWS.   FEBRUARY  18,  1913— Continued 


Sample 
No. 

Hour 
P.  M. 

Location  of  Samples 

Feet 
below 
surface 

Tidal 
current 

Temp, 
water 
Deg.  C. 

Per 

cent, 
land 
water 

Ox3 

C.  C. 
per 
litre 

rgen 

Per 

cent. 

Q'i  t  nrft- 

tion 

Approximate 

Latitude 

Longitude 

348 

349 
350 

4.25 

4.50 
4.55 

Upper  bay,  near  Robbins  Reef  bell 

buoy  

Hudson  river,  midstream  off  Pier  A . . . 
Hudson  river,  midstream  off  Pier  A . . . 

o     /  r 

40  39  10 
40  42  19 
40  42  19 

O        /  V 

74  03  50 
74  01  34 
74  01  34 

40 
1 

30 

Flood 
Flood 
Flood 

1.7 
1.7 
1.7 

30 
40 

36 

6.20 
5.80 
5.90 

71 
65 
67 

351 
352 

5.10 
5.15 

East  river,  midstream,  at  Brooklyn 

Bridge  

East  river,  midstream,  at  Brooklyn 

40  42  20 
40  42  20 

73  59  48 
73  59  48 

1 

30 

Flood 
Flood 

1.7 
1.7 

32 
32 

5.60 
5.70 

64 

65 

3— SLIPS,  EAST  109TH  STREET  AND  WEST  129TH  STREET,  MANHATTAN.    FEBRUARY  14,  1913. 

High  water  occurred  at  Governors  Island  at  1.45  P.  M.    The  wind  was  northwest,  light. 

353 
354 

P.  M. 
12.00 

2.00 

Slip  at  foot  of  East  109th  street,  Har- 
lem river  

Slip  at  foot  of  West  129th  street,  Hud- 
son river  

40  47  24 
40  48  07 

73  56  11 
73  57  45 

1 
1 

Flood 
Flood 

3.9 
2.2 

32 
62 

5.40 
6.00 

68 
66 

4— SLIPS  OF  LOWER  EAST  RIVER  AND  GOWANUS  CANAL.    FEBRUARY  17,  1913. 

High  water  occurred  at  Governors  Island  at  5.20  P.  M.    Low  water  at  11.50  A.  M.    The  wind  was  northwest,  light. 

355 
356 
357 

A.  M. 
10.30 

11.00 

12.00 

Slip  at  foot  of  De  Graw  street,  East 
river,  Broooklyn  

Gowanus  canal,  at  Hamilton  avenue 
bridge  

Gowanus  canal,  at  DeGraw  street,  one 
block  below  pumping  station  at  head 

40  41  13 
40  40  17 

40  41  13 

74  00  25 

73  59  56 

74  00  25 

1 
1 

1 

Ebb 
Ebb 

Slack 

4.4 
3.9 

7.2 

30 
28 

30 

5.20 
5.20 

4.40 

67 
65 

60 

6— SLIPS  OF  LOWER  EAST  RIVER.    FEBRUARY  17,  1913. 

High  water  occurred  at  Governors  Island  at  5.20  P.  M.    Low  water  at  11.50  A.  M.    The  wind  was  northwest,  light. 

358 
359 

P.  M. 
4.00 

4.15 

Slip  of  East  river  just  west  of  Pier  4, 
Manhattan  

Slip  of  East  river  at  foot  of  Coenties 
sliP  

40  42  04 
40  42  08 

74  00  43 
74  00  35 

1 
1 

Flood 
Flood 

3.9 
3.9 

30 
30 

5.40 
5.10 

68 
64 

6— SLIPS  OF  EAST  RIVER  BELOW  24TH  STREET.    FEBRUARY  20,  1913 

High  water  occurred  at  Governors  Island  at  7.35  A.  M.    Low  water  at  2.15  P.  M.    The  wind  was  northwest,  light. 

360 
361 
362 

A.  M. 
10.00 

10.20 

11.00 

Peck  slip,  Bridgeport  Line  pier,  East 
river  

Slip  south  of  dumping  pier  near  Brook- 
lyn Bridge  

Slip  south  of  Pier  32,  East  river  

40  42  26 

40  42  28 
40  42  42 

74  00  04 

74  00  01 
73  59  53 

1 

1 
1 

Ebb 

Ebb 
Ebb 

3.9 

3.9 
3.9 

30 

30 
30 

5.20 

5.20 
5.10 

65 

65 
64 

363 

364 
365 

11.20 

P.  M. 
12.30 

1.00 

Slip  north  of  Pier  32,  East  river,  Nor- 
wich Line  pier  

Slip  between  foot  of  East  23d  and  East 
24  th  streets,  East  river  

Slip  north  of  recreation  pier  at  foot  of 
East  24th  street  

40  42  42 

40  44  08 
40  44  12 

73  59  50 

73  58  31 
73  58  21 

1 

1 
1 

Ebb 

Ebb 
Ebb 

3.9 

4.4 
3.9 

30 

32 
32 

5.10 

5.00 
5.20 

64 

64 

65 

DISSOLVED  OXYGEN  IN  THE  WATER  675 
TABLE  CXXV— Continued 

7— SLIPS  OF  HUDSON  RIVER.    FEBRUARY  20,  1913 


High  water  occurred  at  Governors  Island  at  7.35  A.  M.    Low  water  at  2.15  P.  M.    The  wind  was  northwest,  light. 


Sample 
No. 

Hour 
P.  M. 

Location  of  Samples 

Feet 
below 
surface 

Tidal 
current 

Temp, 
water 
Deg.  C. 

Per 

cent, 
land 
water 

Ox; 
c.  c. 

per 
litre 

fgen 

Per 
cent, 
satura- 
tion 

Approximate 

Latitude 

Longitude 

366 
367 
368 

1.30 
1.45 
2.00 

Slip  at  foot  of  North  Moore  street, 

Manhattan,  Hudson  river  

Slip  at  foot  of  Canal  street,  Pier  32, 

Slip  at  foot  of  Canal  street,  north  of 

O        /  II 

40  43  13 
40  43  28 
40  43  32 

Oil/ 

74  00  48 
74  00  45 
74  00  43 

1 
1 
1 

Ebb 
Ebb 
Ebb 

4.4 
4.4 
4.4 

32 
32 
32 

5.00 
5.00 
5.10 

64 
64 
65 

369 
370 
371 

2.15 
2.30 
3.00 

Slip  between  foot  Jay  and  Duane 
streets,  Manhattan,  Hudson  river. . . 

Slip  between  foot  Vesey  and  Fulton 
streets,  Manhattan,  Hudson  river. . . 

Slip  foot  of  Desbrosses  street,  Hudson 
River  Day  Line  

40  43  06 
40  42  49 
40  43  27 

74  00  50 
74  00  53 
74  00  48 

1 
1 
1 

Ebb 
Ebb 
Ebb 

4.4 
4.4 
4.4 

32 
32 
32 

5.10 
5.20 
4.80 

65 
67 
62 

8— WALLABOUT  CANAL.    FEBRUARY  21,  1913 
High  water  occurred  at  Governors  Island  at  7.55  A.  M.    Low  water  at  3.15  P.  M.    The  wind  was  northwest,  light. 

372 
373 

A.  M. 
11.30 

11.50 

Wallabout  canal,  at  head  of  canal  by 
Fleeman  avenue  market  

Wallabout  canal,  at  head  of  canal  by 
dumping  pier  on  Navy  Yard  side . .  . 

40  42  00 
40  42  00 

73  58  08 
73  58  13 

1 
1 

Ebb 
Ebb 

5.6 
5.6 

32 
32 

4.65 
4.70 

61 
61 

9— NEWTOWN  CREEK.    FEBRUARY  21,  1913 
High  water  occurred  at  Governors  Island  at  7.55  A.  M.    Low  water  at  3.15  P.  M.    The  wind  was  northwest,  light. 

374 
375 
376 

P.  M. 
12.30 

1.15 

2.30 

Newtown  creek,  at  Grand  Street  Bridge 
(Metropolitan  avenue)  

Newtown  creek,  at  Vernon  Avenue 
Bridge  

Newtown  creek,  at  Grand  Street  Bridge 
(Metropolitan  avenue)  

40  42  52 
40  44  22 
40  42  52 

73  55  54 
73  57  20 
73  57  20 

1 
1 
1 

Ebb 
Ebb 
Ebb 

5.6 
5.6 
5.6 

38 
36 
38 

1.60 
1.40 
1.20 

21 
18 
15 

10— SLIPS  IN  LOWER  EAST  RIVER.    FEBRUARY  25,  1913 

High  water  occurred  at  Governors  Island  at  12.10  A.  M.    Low  water  at  6.30  P.  M.    The  wind  was  northwest,  light. 

377 
378 

P.  M. 
4.15 

4.30 

Slip  west  of  Pier  4,  East  river,  Man- 
hattan   

Slip  at  foot  of  Coenties  slip,  East  river, 
Manhattan  

40  42  04 
40  42  08 

74  00  43 
74  00  35 

1 
1 

Ebb 
Ebb 

3.3 
3.3 

36 
36 

5.10 
5.00 

62 
61 

11— HUDSON  RIVER.    APRIL  5,  1913 

High  water  occurred  at  Governors  Island  at  7.45  A.  M.    Low  water  at  2.25  P.  M.    The  wind  was  northwest,  with  a  velocity 
of  30  miles  per  hour. 

379 
380 
381 

A.  M. 
10.35 
10.38 
10.42 

Hudson  river,  midstream,  off  Pier  A.. . 
Hudson  river,  midstream,  off  Pier  A. . 
Hudson  river,  midstream,  off  Pier  A . . 

40  42  19 
40  42  19 
40  42  19 

74  01  34 
74  01  34 
74  01  34 

1 

20 
40 

Ebb 
Ebb 
Ebb 

7.8 
7.8 
7.8 

84 
80 
70 

6.00 
5.90 
5.80 

74 
73 
73 

676 


DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


TABLE  CXXV— Continued 


11— HUDSON  RIVER.    APRIL  5,  1913— Continued 


Sample 
No. 

Hour 
A.  M. 

Location  of  Samples 

Feet 
below 
surface 

Tidal 
current 

Temp, 
water 
Deg.  C. 

Per 
cent, 
land 
water 

Oxy 

C.  C. 
per 
litre 

gen 

Per 
cent, 
satura- 
tion 

Approximate 

Latitude 

Longitude 

382 
383 
384 

11.10 
11.13 
11.16 

Hudson  river,  midstream,  off  Stevens 
Point  

Hudson  river,  midstream,  off  Stevens 
Point  

Hudson  river,  midstream,  off  Stevens 
Point  

O         /  If 

40  44  40 
40  44  40 
40  44  40 

Oil/ 

74  01  04 
74  01  04 
74  01  04 

1 

20 
40 

Ebb 
Ebb 
Ebb 

7.8 
7.8 
7.8 

86 
82 
76 

6.20 
6.10 
5.90 

76 
75 
74 

12— NARROWS,  KILL  VAN  KULL,  ROBBINS  REEF,  HUDSON  AND  EAST  RIVERS.    MAY  29,  1913 

High  water  occurred  at  Governors  Island  at  4.10  P.  M.  Low  water  at  10.20  A.  M.  The  wind  was  northwest,  with  a  velocity 
of  40  miles  per  hour. 

385 
386 
387 
388 

A.  M. 
10.05 
10.20 
10.30 
11.40 

Narrows,  midstream,  between  forts.  .  . 
Narrows,  midstream,  between  forts.  .  . 
Narrows,  midstream,  between  forts.  .  . 
Kill  van  Kull,  midstream,  opposite 
Sailors  Snug  Harbor  

40  36  25 
40  36  25 
40  36  25 

40  38  50 

74  02  48 
74  02  48 
74  02  48 

74  06  25 

1 

30 
60 

1 

Flood 
Flood 
Flood 

Flood 

15.6 
14.4 
14.4 

15.6 

44 
30 
36 

44 

4.40 
5.20 
5.60 

3.90 

68 
84 
91 

61 

389 

390 

391 
392 

11.50 

M 
12.00 

P.  M. 

12.22 
12.55 

Kill  van  Kull,  midstream,  opposite 
Sailors  Snug  Harbor  

Kill  van  Kull,  midstream,  opposite 
Sailors  Snug  Harbor  

Robbins  Reef,  near  bell  buoy  

Robbins  Reef,  near  bell  buoy  

40  38  50 

40  38  50 

40  39  15 
40  39  15 

74  06  25 

74  06  25 

74  03  50 
74  03  50 

15 

30 

1 

20 

Flood 

Flood 

Flood 
Flood 

15.0 

15  0 

15.0 
14.4 

40 

42 

38 
36 

4.40 

4.90 

4.60 
3.90 

70 

77 

73 
60 

393 
394 
395 
396 

1.05 
2.00 
2.15 
2.30 

Robbins  Reef,  near  bell  buoy  

Hudson  river,  midstream,  off  Pier  A. . . 
Hudson  river,  midstream,  off  Pier  A.. . 
Hudson  river,  midstream,  off  Pier  A. . . 

40  39  15 
40  42  19 
40  42  19 
40  42  19 

74  03  50 
74  01  34 
74  01  34 
74  01  34 

40 
1 

15 
30 

Flood 
Flood 
Flood 
Flood 

14.4 
15.3 
15.0 
14.7 

34 
62 
58 
44 

6.00 
4.60 
4.70 
4.30 

95 
70 
71 
64 

397 
398 
399 
400 

3.05 
3.15 
3.30 
4.45 

East  river,  midstream,  at  Brooklyn 
Bridge  

East  river,  midstream,  at  Brooklyn 
Bridge  

East  river,  midstream,  at  Brooklyn 
Bridge  

Narrows,  midstream,  between  forts.  .  . 

40  42  20 

40  42  20 

40  42  20 
40  36  25 

73  59  48 
73  59  48 

73  59  48 

74  02  48 

1 

15 

30 
1 

Flood 

Flood 

Flood 
Ebb 

15.3 

15.0 

15.0 
15.0 

52 

48 

56 
34 

4.70 

4.50 

2.90 
5.20 

72 

70 

45 
84 

401 

402 
403 

404 

5.00 
5.10 
5.55 

6.05 

Narrows,  midstream,  between  forts.  .  . 
Narrows,  midstream,  between  forts.  .  . 
Kill  van  Kull,  midstream,  off  Sailors 

Snug  Harbor  

Kill  van  Kull,  midstream,  off  Sailors 

Snug  Harbor  

40  36  25 
40  36  25 

40  38  50 

40  38  50 

74  02  48 
74  02  48 

74  06  25 

74  06  25 

30 
60 

1 

15 

Ebb 
Ebb 

Ebb 

Ebb 

14.7 
14.4 

15.0 

15.0 

32 
26 

40 

20 

5.90 
5.90 

5.10 

5.10 

93 
94 

86 

81 

405 

406 
407 
408 

6.15 

6.45 
7.00 
7.15 

Kill  van  Kull,  midstream,  off  Sailors 

Snug  Harbor  

Robbins  Reef,  near  bell  buoy  

Robbins  Reef,  near  bell  buoy  

Robbins  Reef,  near  bell  buoy  

40  38  50 
40  39  15 
40  39  15 
40  39  15 

74  06  25 
74  03  50 
74  03  50 
74  03  50 

30 
1 
20 
40 

Ebb 
Ebb 
Ebb 
Ebb 

15.0 
15.0 
14.4 
14.4 

40 
42 
40 
34 

5.70 
5.00 
5.50 
5.10 

90 
78 
84 
78 

409 
410 
411 

7.50 
8.00 
8.10 

Hudson   river,   midstream,  opposite 

Colgates  

Hudson   river,   midstream,  opposite 

Hudson   river,   midstream,  opposite 

40  42  19 
40  42  19 
40  42  19 

74  01  34 
74  01  34 
74  01  34 

1 
15 

30 

Ebb 
Ebb 
Ebb 

14.4 
14.4 
14.4 

60 
52 
46 

5.00 
5.30 
5.50 

75 
79 
84 

DISSOLVED  OXYGEN  IN  THE  WATER 


677 


TABLE  CXXV— Continued 

13— EAST  RIVER,  HUDSON  RIVER,  ROBBINS  REEF,  KILL  VAN  KULL  AND  NARROWS.    JUNE  11,  1913 

High  water  occurred  at  Governors  Island  at  2.10  P.  M.  Low  water  at  8.10  A.  M.  The  wind  was  west,  with  a  velocity  of 
5  miles  per  hour. 


Sample 
No. 


412 
413 
414 
415 


416 
417 
418 
419 


420 
421 

422 

423 


Hour 
A.M. 


9.05 
9.15 
9.25 
9.45 


9.50 
9.55 
10.30 
10.40 


10.50 
11.05 

11.15 

11.20 


Location  of  Samples 


Approximate 


East  river,  midstream,  at  Brooklyn 

Bridge  

East  river,  midstream,  at  Brooklyn 

Bridge  

East  river,  midstream,  at  Brooklyn 

Bridge  

Hudson  river,  midstream,  off  Pier  A 

Hudson  river,  midstream,  off  Pier  A 
Hudson  river,  midstream,  off  Pier  A 

Robbins  Reef,  near  bell  buoy  

Robbins  Reef,  near  bell  buoy  

Robbins  Reef,  near  bell  buoy  

Kill  van  Kull,  midstream,  off  Sailors 

Snug  Harbor  

Kill  van  Kull,  midstream,  off  Sailors 

Snug  Harbor  

Kill  van  Kull,  midstream,  off  Sailors 
Snug  Harbor  

Narrows,  midstream,  between  forts . . . 
Narrows,  midstream,  between  forts .  .  . 
Narrows,  midstream,  between  forts . . . 
East  river,  midstream,  at  Brooklyn 
Bridge  

East  river,  midstream,  at  Brooklyn 

Bridge  

East  river,  midstream,  at  Brooklyn 

Bridge  

Hudson  river,  midstream,  off  Pier  A . . 
Hudson  river,  midstream,  off  Pier  A .  . 
Hudson  river,  midstream,  off  Pier  A . . 

Robbins  Reef,  near  bell  buoy  

Robbins  Reef,  near  bell  buoy  

Robbins  Reef,  near  bell  buoy  

Kill  van  Kull,  midstream,  off  Sailors 
Snug  Harbor  

Kill  van  Kull,  midstream,  off  Sailors 
Harbor  

Kill  van  Kull,  midstream,  off  Sailors 
Snug  Harbor  

Narrows,  midstream,  between  forts . 

Narrows,  midstream,  between  forts . 

Narrows,  midstream,  between  forts . 


Latitude 


40  42  20 

40  42  20 

40  42  20 
40  42  19 


40  42  19 
40  42  19 
40  39  10 
40  39  10 


40  39  10 
40  38  50 
40  38  50 
40  38  50 


Longitude 


73  59  48 
73  59  48 

73  59  48 

74  01  34 


74  01  34 
74  01  34 
74  03  50 
74  03  50 


74  03  50 
74  06  25 
74  06  25 
74  06  25 


Feet 
below 
surface 


1 

15 

30 
1 


15 
30 
1 

20 


40 
1 
15 
30 


Tidal 
current 


Flood 

Flood 

Flood 
Flood 


Flood 
Flood 
Flood 
Flood 


Flood 
Flood 
Flood 
Flood 


Temp, 
water 
Deg.  C. 


16.5 

16.5 

16.5 
17.7 


17.7 
17.5 
17.7 
17.7 


18.5 
17.7 
17.7 
18.5 


Per 

cent, 
land 
water 


34 

34 

34 
51 


47 
40 
43 
38 


34 
34 
34 
34 


Oxygen 


C.  C. 
per 
litre 


2.49 

2.80 

2.51 
3.77 


5.08 
3.97 
4.37 
5.90 


5.58 
4.39 
4.21 
3.92 


Per 
cent, 
satura- 
tion 


40 
45 

41 

60 


82 
65 
71 
97 


93 
73 
71 
66 


424 
425 
426 
427 


P.  M. 
12.05 
12.10 
12.15 
1.05 


40  36  25 
40  36  25 
40  36  25 

40  42  20 


74  02  48 
74  02  48 
74  02  48 

73  59  48 


1 

30 
60 


Flood 
Flood 
Flood 

Flood 


18.5 
17.7 
16.8 

18.4 


30 
30 
33 

40 


4.11 
4.21 
4.15 

4.83 


70 
70 
67 

85 


428 

429 

430 
431 
432 


433 
434 
435 
436 


1.15 

1.25 

1.50 
1.55 
2.00 


40  42  20 


40  42  20 
40  42  19 
40  42 
40  42 


19 
19 


73  59  48 

73  59  48 

74  01  34 
74  01  34 
74  01  34 


15 

30 
1 
15 
30 


Flood 

Flood 
Flood 
Flood 
Flood 


17.8 

17.8 
18.4 
17.8 
17.2 


40 

39 
40 
43 
40 


4.56 

5.08 
4.11 
4.12 
4.72 


2.45 
2.50 
3.00 
3.30 


40  39  10 
40  39  10 
40  39  10 

40  38  50 


74  03  50 
74  03  50 
74  03  50 

74  06  25 


1 

20 
40 


Ebb 
Ebb 
Ebb 

Ebb 


17.8 
17.8 
17.2 

18.4 


29 
24 
27 

36 


5.26 
5.36 
5.83 

4.61 


75 

84 
68 
69 
77 


89 
91 
98 

78 


437 

438 

439 
440 
441 


3.35 

3.45 

4.20 
4.25 
4.35 


40  38  50 


40  38 
40  36 
40  36 
40  36 


50 
25 
25 
25 


74  06  25 

74  06  25 
74  02  48 
74  02  48 
74  02  48 


15 

30 
1 
30 
60 


Ebb 

Ebb 
Ebb 
Ebb 
Ebb 


17.8 

17.2 
18.0 
17.2 
16.7 


35 

50 
29 
28 
24 


4.40 


33 
66 
32 
07 


73 

72 
96 
89 
102 


14 — EAST  RIVER  AT  BROOKLYN  BRIDGE.    JUNE  17,  1913 


Low  water  occurred  at  Governors  Island  at  1.45  P.  M.    The  wind  was  southwest,  with  a  velocity  of  5  miles  per  hour. 


P.  M. 

442 

2.13 

100  feet  off  North  Pier  headline  

40  42  25 

73 

59  53 

1 

Flood 

20.0 

31 

0.40 

7 

443 

2.20 

100  feet  off  North  Pier  headline  

40  42  25 

73 

59  53 

18 

Flood 

19.4 

31 

2.71 

48 

444 

2.25 

100  feet  off  North  Pier  headline  

40  42  25 

73 

59  53 

35 

Flood 

19.4 

31 

2.67 

47 

445 

2.30 

Midstream  

40  42  20 

73 

59  48 

1 

Flood 

19.4 

31 

2.73 

48 

446 

2.35 

Midstream  

40  42  20 

73 

59  48 

18 

Flood 

19.4 

31 

2.12 

37 

t 


678 


DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


TABLE  CXXV— Continued 

14— EAST  RIVER,  HUDSON  RIVER,  ROBBINS  REEF,  KILL  VAN  KULL  AND  NARROWS.    JUNE  11,  1913— Continued 


Sample 
No. 


Hour 
P.  M. 


Location  of  Samples 


Approximate 


Latitude 


Longitude 


Feet 
below 
surface 


Tidal 
current 


Temp, 
water 
Deg.  C. 


Per 

cent, 
land 
water 


Oxygen 


C.  C. 
per 
litre 


Per 
cent, 
satura- 
tion 


447 
448 


449 
450 


2.40 
2.50 


2.55 
3.00 


Midstream  

500  feet  east  of  Brooklyn  Bridge  and 
100  feet  off  pier  headline  on  south 
shore  

500  feet  east  of  Brooklyn  Bridge  and 
100  feet  off  pier  headline  on  south 
shore  

500  feet  east  of  Brooklyn  Bridge  and 
100  feet  off  pier  headline  on  south 
shore  


O         /  It 

40  42  20 
40  42  15 
40  42  15 
40  42  15 


73  59  48 


73  59  43 


73  59  43 


73  59  43 


35 


18 


35 


Flood 


Flood 


Flood 


Flood 


19.4 


19.4 


18.9 


19.4 


30 


31 


32 


31 


3.56 


2.47 


2.07 


2.06 


62 


43 


35 


30 


15— EAST  RrVER,  CROSS-SECTION,  PIER  NO.  10.    JULY  2,  1913 

High  water  occurred  at  Governors  Island  at  7.15  A.  M.  Low  water  at  1.10  P.  M.  The  wind  was  southwest,  with  a  velocity 
of  5  miles  per  hour. 


A.  M. 
7.25 
7.30 
7.35 
7.37 


100  feet  of  west  shore . 
100  feet  off  west  shore 
100  feet  off  west  shore 

Y  way  over  

Y  way  over  

Y  way  over  

Y.  way  over  

Yi  way  over  

Y<i  way  over  

Y  way  over  

%  way  over  

%  way  over  

100  feet  off  east  shore. 
100  feet  off  east  shore. 
100  feet  off  east  shore. 
100  feet  off  west  shore 

100  feet  off  west  shore 
100  feet  off  west  shore 

Y  way  over  

Y  way  over  

Y  way  over  

Yi  way  over  

Yi  way  over  

Yi  way  over  

YL  way  over  

Y  way  over  

%  way  over  

100  feet  off  east  shore . 

100  feet  off  east  shore. 
100  feet  off  east  shore . 

100  feet  off  west  shore 
100  feet  off  west  shore 

100  feet  off  west  shore 

Y  way  over  

Y  way  over  

Y  way  over  

Yi  way  over  


40  42  09 
40  42  09 
40  42  09 
40  42  07 


74  00  22 
74  00  22 
74  00  22 
74  00  17 


1 

15 
30 
1 


Ebb 
Ebb 
Ebb 
Ebb 


22.2 
21.7 
21.7 
21.7 


31 

30 
30 
30 


2.34 
2.82 
2.63 
2.49 


7.41 
7.45 
7.50 
7.52 


40  42  07 
40  42  07 
40  42  03 
40  42  03 


74  00  17 
74  00  17 
74  00  11 
74  00  11 


15 
30 
1 
15 


Ebb 
Ebb 
Ebb 
Ebb 


21.7 
21.7 
21.4 
21.7 


30 
26 
26 
26 


2.97 
2.94 
2.30 
2.56 


7.55 
8.00 
8.05 
8.10 


40  42  03 
40  42  00 
40  42  00 
40  42  00 


74  00  11 

74  00  05 
74  00  05 
74  00  05 


30 
1 
15 

30 


Ebb 
Ebb 
Ebb 
Ebb 


21.7 
21.4 
21.4 
21.7 


30 
31 
26 
30 


3.32 
2.51 
2.63 
2.99 


8.20 
8.25 
8.30 
9.55 


10.00 
10.05 
10.10 
10.12 


40  41  57 

40  41  57 

40  41  57 

40  42  09 


74  00  00 
74  00  00 
74  00  00 
74  00  22 


1 

15 
30 
1 


Ebb 
Ebb 
Ebb 
Ebb 


21.9 
21.7 
21.4 

23.3 


31 
31 
30 
30 


2.36 
1.96 
2.73 
2.44 


40  42  09 
40  42  09 
40  42  07 
40  42  07 


74  00  22 
74  00  22 
74  00  17 
74  00  17 


15 
30 
1 
15 


Ebb 
Ebb 
Ebb 
Ebb 


22.2 
21.7 
22.2 
21.7 


31 
31 
31 
31 


1.92 
2.14 
2.28 
1.85 


10.15 
10.20 
10.25 
10.27 


40  42  07 
40  42  03 
40  42  03 
40  42  03 


74  00  17 
74  00  11 
74  00  11 
74  00  11 


30 
1 
15 

30 


Ebb 
Ebb 
Ebb 
Ebb 


21.7 

22.0 
22.0 
21.7 


31 
31 
35 
36 


3.04 
1.90 
1.54 
2.67 


10.28 
10.30 
10.35 
10.40 


40  42  00 
40  42  00 
40  42  00 
40  41  57 


74  00  05 
74  00  05 
74  00  05 
74  00  00 


1 

15 
30 
1 


Ebb 
Ebb 
Ebb 
Ebb 


21.7 
21.7 
21.7 
21.7 


34 
31 
31 
34 


2.29 
1.52 
2.60 
2.34 


10.43 
10.48 
P.  M. 
12.30 
12.35 


40  41  57 
40  41  57 

40  42  09 
40  42  09 


74  00  00 
74  00  00 

74  00  22 
74  00  22 


15 
30 

1 

15 


Ebb 
Ebb 

Flood 
Flood 


21 
21 

23 
22 


34 
34 

32 
31 


0.83 
2.60 

1.39 
1.42 


12.40 
12.42 
12.46 
12.50 
12.55 


40  42  09 
40  42  07 
40  42  07 
40  42  07 
40  42  03 


74  00  22 
74  00  17 
74  00 
74  00 
74  00 


17 
17 
11 


30 
1 
15 
30 
1 


Flood 
Flood 
Flood 
Flood 
Flood 


22.2 
21.7 
21.7 
21.7 
21.7 


31 
31 
31 
31 
31 


0.99 
1.67 
1.33 
2.80 
0.69 


DISSOLVED  OXYGEN  IN  THE  WATER  679 

TABLE  CXXV— Continued 


16 — EAST  RIVER,  CROSS-SECTION,  PIER  NO.  10.    JULY  2,  1913— Continued 


Sample 

ISO. 

Hour 
r.  IV1. 

Location  of  Samples 

Feet 
below 
surface 

Tidal 
current 

Temp, 
water 
Deg.  C. 

Per 

cent, 
land 
water 

Oxj 

C.  C. 
per 
litre 

gen 

Per 
cent, 
satura- 
tion 

Approximate 

Latitude 

Longitude 

489 
490 
491 

1 0  £7 

1.00 
1.07 
1.10 

Yi  way  over  

Yi  way  over  

J£  way  over  

Oft 

40  42  03 
40  42  03 
40  42  00 
40  42  00 

o      t  r 

74  00  11 
74  00  11 
74  00  05 
74  00  05 

1  K 

30 
1 
15 

r  iooq 
Flood 
Flood 
Flood 

91  7 

21.7 
21.7 
21.7 

31 
31 
31 
31 

n  so, 

1.85 
1.89 
2.22 

Ifi 
34 
34 
40 

AG9 

493 
494 
495 

1  19 

1 .  1Z 

1.17 
1.20 
1.25 

%  way  over  

100  feet  off  east  shore  

100  feet  off  east  shore  

100  feet  off  east  shore  

40  42  00 
40  41  57 
40  41  57 
40  41  57 

74  00  05 
74  00  00 
74  00  00 
74  00  00 

OU 

l 

15 

30 

r  iooq 
Flood 
Flood 
Flood 

91  7 

22.2 
21.7 
21.7 

Ol 

31 
34 
31 

n  on 
2.19 
1.85 
0.97 

Ifi 
40 
33 
18 

AQA 

^yo 
497 
498 
499 

2.43 
2.47 
2.50 

100  feet  off  west  shore  

100  feet  off  west  shore  

100  feet  off  west  shore  

40  42  09 
40  42  09 
40  42  09 
40  42  07 

74  00  22 
74  00  22 
74  00  22 
74  00  17 

15 
30 
1 

r  iooq 
Flood 
Flood 
Flood 

99  a 
21.7 
21.7 
22.2 

9fi 

31 
30 
33 

1  7^ 

2.42 
2.41 
3.67 

39 
44 
53 
67 

501 
502 
503 

9  5\Q 

Z .  Do 

2.55 
3.00 
3.03 

Yi  way  over  

40  42  07 
40  42  07 
40  42  03 
40  42  03 

74  00  17 
74  00  17 
74  00  11 
74  00  11 

1  K 

ID 

30 
1 
15 

J;  IOOQ 

Flood 
Flood 
Flood 

99  9 
—  .  & 

21.7 
22.0 
22.0 

OU 

31 

33 
33 

1  .  OO 

2.11 
1.89 
1.45 

33 

38 
34 
26 

Jin 

505 
506 
507 

O  .  UO 

3.10 
3.13 
3.15 

%  way  over  

%  way  over  

40  42  03 
40  42  00 
40  42  00 
40  42  00 

74  00  11 
74  00  05 
74  00  05 
74  00  05 

30 
OU 

1 
15 
30 

JC  IOOQ 

Flood 
Flood 
Flood 

99  f> 

22.2 
21.7 
21.7 

oo 

35 
35 
33 

9  84 

2.61 
2.02 
2.20 

Ol 

47 
36 
40 

509 
510 
511 

o  .  - 1  J 

3.23 
3.28 
4.55 

100  feet  off  east  shore  

100  feet  off  east  shore  

100  feet  off  east  shore  

100  feet  off  Pier  10,  Manhattan  

40  41  57 
40  41  57 
40  41  57 
40  42  09 

74  00  00 
74  00  00 
74  00  00 
74  00  22 

| 

15 
30 
1 

r  J.OOQ 

Flood 
Flood 
Flood 

99  9 

21.7 
21.7 
22.2 

33 

33 
33 
33 

9  *iQ 

1.45 
1.97 
1.54 

rto 

26 
36 
28 

M9 

513 
514 
515 

A  RQ 

**  .  OO 

5.03 
5.06 
5.09 

100  feet  off  Pier  10,  Manhattan  

100  feet  off  Pier  10,  Manhattan  

x/z  way  across  

V%  way  across  

40  42  09 
40  42  09 
40  42  03 
40  42  03 

74  00  22 
74  00  22 
74  00  11 
74  00  11 

1  * 

30 
1 
15 

x  IOOQ 

Flood 
Flood 
Flood 

91  7 

21.7 

22.2 
21.7 

3fi 

33 
33 
33 

2  31 
0.88 
1.58 

1  ^ 

41 
14 

29 

\JX\J 

517 
518 
519 

5  19 

5.15 
5.18 
5.21 

5^  way  across  

%  way  across  

%  way  across  

40  42  03 
40  42  00 
40  42  00 
40  42  00 

74  00  11 
74  00  05 
74  00  05 
74  00  05 

30 
1 
15 
30 

Flood 
Flood 
Flood 
Flood 

99  9 
—  .  - 

22.0 
21.7 
21.7 

35 
OO 

40 
36 
33 

9  QQ 

2.67 
2.45 
3.43 

47 
43 
63 

521 
522 
523 

o .  — o 

5.28 
5.31 
6.20 

100  feet  off  Pier  10,  Brooklyn  

100  feet  off  Pier  10,  Brooklyn  

100  feet  off  Pier  10,  Brooklyn  

100  feet  off  Pier  10,  Manhattan  

40  41  57 
40  41  57 
40  41  57 
40  42  09 

74  00  00 
74  00  00 
74  00  00 
74  00  22 

1 

15 
30 
1 

|*  IOOQ 

Flood 
Flood 
Flood 

91  7 

21.7 
21.7 
22.2 

Ol 

36 
36 
34 

9  9Q 

2.35 
2.54 
0.84 

4.1 

42 
44 
15 

594 

525 
526 
527 

fi  99 

6.25 
6.30 
6  35 

100  feet  off  Pier  10,  Manhattan  

100  feet  off  Pier  10,  Manhattan  

Y,  way  across  

Y  way  across  

40  42  09 
40  42  09 
40  42  07 
40  42  07 

74  00  22 
74  00  22 
74  00  17 
74  00  17 

ID 

30 
1 
15 

r  100  Q 

Flood 
Flood 
Flood 

01  7 

21.7 
21.7 
21.1 

OO 

33 
32 
32 

l> .  OO 

2.32 
1.58 
2.36 

42 
29 
40 

528 
529 
530 
531 

6.38 
6.41 
6.45 
6.48 

Y  w»y  across  

Yt  way  across  

Y  way  across  

40  42  07 
40  42  03 
40  42  03 
40  42  03 

74  00  17 
74  00  11 
74  00  11 
74  00  11 

30 
1 
15 

35 

Flood 
Ebb 
Ebb 
Ebb 

21.7 
21.7 
21.7 
21.7 

34 
33 
32 
32 

3.13 
1.81 
3.15 
2.81 

55 
32 
57 
50 

532 
533 
534 
535 

6.52 
6.55 
7.00 
7.04 

Y  way  across  

%  way  across  

Y  way  aqross  

100  feet  off  Pier  10,  Brooklyn  

40  42  00 
40  42  00 
40  42  00 
40  41  57 

74  00  05 
74  00  05 
74  00  05 
74  00  00 

1 

15 
30 
1 

Ebb 
Ebb 
Ebb 
Ebb 

21.7 
21.7 
21.7 
21.7 

32 
32 
32 
32 

2.90 
2.13 
2.74 
2.74 

52 
38 
50 
50 

536 
537 

7.08 
7.10 

100  feet  off  Pier  10,  Brooklyn  

100  feet  off  Pier  10,  Brooklyn  

40  41  57 
40  41  57 

74  00  00 
74  00  00 

15 
30 

Ebb 
Ebb 

21.7 
21.7 

32 
32 

2.05 
2.73 

37 
50 

680 


DATA  RELATING  TO  THE  PROTECTION  OF  THE  IIARROR 


TARLE  CXXV— Continued 
16— NARROWS,  CROSS  SECTION,  BETWEEN  FORTS  LAFAYETTE  AND  WADSWORTH.   JULY  3,  1913 


High  water  occurred  at  Governors  Island  at  8.05  A.  M.  Low  water  at  2.15  P.  M.  The  wind  was  southwest,  with  a  velocity 
of  5  miles  per  hour. 


Sample 
No. 

Hour 
A.  M. 

Location  of  Samples 

Feet 
below 
surface 

Tidal 
current 

Temp, 
water 
Deg.  C. 

Per 

cent, 
land 
water 

Ay, 

C.  C. 
per 
litre 

'gen 

Per 
cent, 
satura- 
tion 

Approximate 

Latitude 

Longitude 

538 
539 
i4n 

641 

7.40 
7.45 

7  in 

7.55 

200  feet  off  Fort  Lafayette  

200  feet  off  Fort  Lafayette  

200  feet  otf  b  ort  Lafayette  

Y  way  across  

Off 

40  36  29 
40  36  29 

A  f\       O  /*  C\i\ 

40  36  29 
40  36  27 

74  02  24 
74  02  24 
74  02  24 
74  02  34 

1 

15 

^n 

1 

Ebb 
Ebb 

Ebb 

20.6 
20.8 
9n  fi 

20.8 

24 
20 
9n 

22 

4.35 
3.60 

3.44 

78 
65 

7Q 

62 

542 
543 

K44 

545 

8.00 
8.05 

fi    1  1 

o  .  lO 

8.17 

}4  way  across  

Y\  way  across  

Yi  way  across  

Yz  way  across  

40  36  27 
40  36  27 
40  36  25 
40  36  25 

74  02  34 
74  02  34 

t  a    f\n    a  n 

74  02  48 
74  02  48 

20 
40 

30 

Ebb 
Ebb 

Ebb 

20.3 
20.0 
9n  fi 

20.6 

20 
21 

94 

24 

3.12 
2.48 
0 . 00 
3.89 

56 
62 
fin 

69 

546 
547 

549 

8.20 
8.25 

8  9Q 

8.32 

Yi  way  across  

%  way  across  

%  way  across  

way  across  

40  36  25 
40  36  23 
40  3o  23 
40  36  23 

74  02  48 
74  03  02 
74  03  02 
74  03  02 

60 
1 
9n 

40 

Ebb 
Ebb 

-EjUU 

Ebb 

20.0 
20.6 

90  fi 

20.0 

21 
24 
9n 

A,\J 

21 

4.30 
4.05 
^  fifi 
3.92 

79 
73 
fifi 

70 

550 
551 

553 

8.39 
8.43 

8  41 

9.52 

200  feet  off  Fort  Wadsworth  

200  feet  off  Fort  Wadsworth  

200  feet  off  Fort  Wadsworth  

OAA  C    „A    „  Ct              A    T      f—         A.  a. 

200  feet  off  rort  Lafayette  

40  36  21 
40  36  21 
40  36  21 
40  36  29 

74  03  12 
74  03  12 
74  03  12 
74  02  24 

1 

20 

1 

Ebb 
Ebb 

Ebb 

21.1 

20.6 
9n  n 

21.7 

26 
22 

99 

27 

4.26 
3.87 
4  sn 
3.40 

77 
70 

62 

554 
555 
556 
117 

OO  i 

9.55 
10.00 
10.05 
in  in 

200  feet  off  Fort  Lafayette  

200  feet  off  Fort  Lafayette  

\i  way  across  

\4  way  across  

40  36  29 
40  36  29 
40  36  27 
40  36  27 

74  02  24 
74  02  24 
74  02  34 
74  02  34 

15 
30 
1 

9n 

Ebb 
Ebb 
Ebb 

21.7 
21.7 
21.7 

91  1 

Ail.  .  A 

23 
22 
26 

91! 
LO 

3.71 
3.70 
3.19 

9Q 

70 

68 
59 

1Q 

558 
559 
560 

ODI 

10.15 
10.20 
10.25 
i  n  3f> 

\i  way  across  

Y2  way  across  

Yi  way  across  

Y2.  way  across  

40  36  27 
40  36  25 
40  36  25 
40  36  25 

74  02  34 
74  02  48 
74  02  48 
74  02  48 

40 
1 

30 

OU 

Ebb 
Ebb 
Ebb 

11;  DO 

20.6 
21.7 
21.1 
9n  fi 

Ai\J  .  O 

20 
32 
22 
9n 

4.48 
3.30 
3.81 
4  4n 

81 
60 
69 
on 

562 
563 
564 

ODO 

10.33 
10.36 
10.40 
in  47 

%  way  across  

%  way  across  

%  way  across  

200  feet  off  Fort  Wadsworth  

40  36  23 
40  36  23 
40  36  23 
40  36  21 

74  03  02 
74  03  02 
74  03  02 
74  03  12 

1 

20 
40 

1 
1 

Ebb 
Ebb 
Ebb 

22.2 
20.6 
20.3 

99  9 

Lit  .  A, 

30 
20 
20 

9Q 

3.72 
4.04 
3.90 

^  41 

68 
73 
71 

fi9 

666 
567 

IfiS 
OOO 

569 

10.50 
10.55 
P.  M. 
19  in 

12.15 

200  feet  off  Fort  Wadsworth  

200  feet  off  Fort  Wadsworth  

200  feet  off  Fort  Lafayette  

200  feet  off  Fort  Lafayette  

40  36  21 
40  36  21 

40  36  29 
40  36  29 

74  03  12 
74  03  12 

74  02  24 
74  02  24 

20 
40 

I 

15 

Ebb 
Ebb 

Ebb 

21.7 
20.6 

99  n 
21.7 

29 
22 

9Q 

23 

3.45 
4.19 

4  74 

3.11 

63 
76 

Kfi 

70 

570 
571 
572 
673 

12.20 
12.25 
12.30 
12.35 

200  feet  off  Fort  Lafayette  

14  way  across  

14  way  across  

Y  way  across  

40  36  29 
40  36  27 
40  36  27 
40  36  27 

74  02  24 
74  02  34 
74  02  34 
74  02  34 

30 
1 
20 
40 

Ebb 
Ebb 
Ebb 
Ebb 

21.2 
21.7 
21.7 
21 .7 

23 
29 
27 
26 

3.74 
2.89 
2.78 
3.50 

68 
52 
50 
64 

574 
575 
576 
577 

12.40 
12.43 
12.45 
12.50 

Yi  way  across  

Yi  way  across  

Yi  way  across  

%  way  across  

40  36  25 
40  36  25 
40  36  24 
40  36  23 

74  02  48 
74  02  48 
74  02  48 
74  03  02 

1 

30 
60 
1 

Ebb 
Ebb 
Ebb 
Ebb 

21.7 
21.7 
21.7 
21.7 

27 
27 
25 
29 

2.85 
2.62 
3.73 
3.51 

52 
48 
68 
64 

578 
579 
580 
681 

12.55 
1.00 
1.05 
1.10 

Yi  way  across  

%  way  across  

200  feet  off  Fort  Wadsworth  

200  feet  off  Fort  Wadsworth  

40  36  23 
40  36  23 
40  36  21 
40  36  21 

74  02  03 
74  03  02 
74  03  12 
74  03  12 

20 
40 
1 

20 

Ebb 
Ebb 
Flood 
Flood 

21.7 
21.7 
22.2 
21.7 

27 
27 
29 
29 

3.43 
3.34 
2.89 
3.14 

63 
60 
54 
57 

582 
583 
584 
585 

1.15 

2.25 
2.30 
2.35 

200  feet  off  Fort  Wadsworth  

200  feet  off  Fort  Lafayette  

200  feet  off  Fort  Lafayette  

200  feet  off  Fort  Lafayette  

40  36  21 
40  36  29 
40  36  29 
40  36  29 

74  03  12 
74  02  24 
74  02  24 
74  02  24 

40 
1 
15 
40 

Flood 
Flood 
Flood 
Flood 

21.4 
22.0 
21.7 
21.7 

27 
32 
27 
27 

4.94 

2.69 
3.23 
2.65 

88 
43 
58 
48 

DISSOLVED  OXYGEN  IN  THE  WATER 


681 


TABLE  CXXV— Continued 


16— NARROWS,  CROSS  SECTION,  BETWEEN  FORTS  LAFAYETTE  AND  WADSWORTH.    JULY  3,  1913— Continued 


Sample 
No. 

Hour 
P.  M. 

Location  of  Samples 

Feet 
below 
surface 

Tidal 
current 

Temp, 
water 

Dor,  P 

ueg.  Kj. 

Per 
cent, 
land 
water 

Ox; 

C.  C. 
per 
litre 

fgen 

Per 
cent, 
satura- 
tion 

Approximate 

Latitude 

Longitude 

586 
587 
588 
589 

2.43 
2.45 
2.50 
2.57 

I/*  wav  across 

Y±  way  across  

Yi  way  across  

0    1  11 

40  36  27 
40  36  27 
40  36  27 
40  36  25 

0    1  a 

74  02  34 
74  02  34 
74  02  34 
74  02  48 

1 

20 
40 
1 

Flood 
Flood 
Flood 
Flood 

21.7 
21.7 
21.7 

22.2 

32 
27 
25 
33 

3.38 
2.66 
3.31 
3.07 

61 

49 
60 
56 

590 
591 
592 
593 

3.00 
3.10 
3.12 
3.15 

Yi  way  across 

Yi  way  across  

%  way  across  

%  way  across  

40  36  25 
40  36  25 
40  36  23 
40  36  23 

74  02  48 
74  02  48 
74  03  02 
74  03  02 

30 
60 
1 

20 

Flood 
Flood 
Flood 
Flood 

22.2 
21.2 
22.2 
21.2 

27 
33 
33 
29 

3.20 
3.30 
3.64 
3.73 

59 
59 
66 
67 

594 
595 
596 
597 

3.24 
3.30 
3.35 
3.40 

way  across 

200  feet  off  Fort  Wadsworth  

200  feet  off  Fort  Wadsworth  

200  feet  off  Fort  Wadsworth  

40  36  23 
40  36  21 
40  36  21 
40  36  21 

74  03  02 
74  03  12 
74  03  12 
74  03  12 

40 
1 

20 
40 

Flood 
Flood 
Flood 
Flood 

21.2 
22.2 
21.2 
21.2 

27 
27 
24 
24 

3.80 
3.52 
3.74 
3.91 

68 
65 
68 
71 

598 
599 
600 
601 

4.40 
4.46 
4.53 
5.00 

M<J  leet  on  rort  Liaiayette  

200  feet  off  Fort  Lafayette  

200  feet  off  Fort  Lafayette  

y±  way  across  

4U  oO  Z\) 

40  36  29 
40  36  29 
40  36  27 

/4  vjz  z± 
74  02  24 
74  02  24 
74  02  34 

1 
15 
30 

1 

Flood 
Flood 
Flood 
Flood 

22.2 
21.1 
21.1 

22.2 

25 
24 
24 
27 

4.04 
3.67 
3.67 
3.47 

75 
66 
66 
64 

602 
603 
604 
605 

5  03 
5.10 
5.20 
5.24 

l/i  way  across  

Y±  way  across  

Y2  way  across  

Yl  way  across  

40  36  27 
40  36  27 
40  36  25 
40  36  25 

74  02  34 
74  02  34 
74  02  48 
74  02  48 

20 
40 
1 

30 

Flood 
Flood 
Flood 
Flood 

21  1 
22.2 
21.1 
22.2 

28 
27 
28 
27 

3  67 
4.26 
3.81 
3.30 

66 
78 
70 
60 

606 
607 
608 
609 

5.26 
5.30 
5.35 
5.40 

Yi  way  across  

%  way  across  

Y±  way  across  

Y±  way  across  

40  36  25 
40  36  23 
40  36  23 
40  36  23 

74  02  48 
74  03  02 
74  03  02 
74  03  02 

60 
1 
20 
40 

Flood 
Flood 
Flood 
Flood 

21.1 
21.7 
22.2 
21.1 

18 
27 
27 
18 

3.53 
3.67 
4.04 
3.56 

66 
67 
79 
66 

610 
611 
612 

5.45 
5.50 
5.55 

200  feet  off  Fort  Wadsworth  

200  feet  off  Fort  Wadsworth  

200  feet  off  Fort  Wadsworth  

40  36  21 
40  36  21 
40  36  21 

74  03  12 
74  03  12 
74  03  12 

1 

15 
30 

Flood 
Flood 
Flood 

22.2 
22.2 
21.1 

27 
25 
25 

3.70 
4.18 
4.56 

69 
77 
83 

17— EAST  RIVER,  BROOKLYN  BRIDGE  TO  118TH  STREET.    JULY  7,  1913 

High  water  occurred  at  Governors  Island  at  12.35  P.  M.  Low  water  at  6.50  P.  M.   The  wind  was  northwest,  with  a  velocity 
of  5  miles  per  hour. 

613 
614 
615 
616 

P.  M. 
1.35 
1.40 
1.45 
1.53 

Midstream,  at  Brooklyn  Bridge  

Midstream,  at  Brooklyn  Bridge  

Midstream,  at  Brooklyn  Bridge  

Midstream,  at  Manhattan  Bridge  

40  42  20 
40  42  20 
40  42  20 
40  42  25 

73  59  48 
73  59  48 
73  59  48 
73  59  28 

1 

15 
30 
1 

Ebb 
Ebb 
Ebb 
Ebb 

22.0 
22.0 
22.0 
22.0 

29 
29 
29 
29 

2.62 
1.84 
1.87 
1.96 

48 
33 
34 
36 

617 
618 
619 

620 

1.57 
2.00 
2.15 
2.20 

Midstream,  at  Manhattan  Bridge  

Midstream,  at  Manhattan  Bridge 

Entrance  to  Wallabout  bay  

Entrance  to  Wallabout  bay  

40  42  25 
40  42  25 
40  42  30 
40  42  30 

73  59  28 
73  59  28 
73  58  15 
73  58  15 

15 
30 
1 
15 

Ebb 
Ebb 
Ebb 
Ebb 

22.2 
21.7 
21.7 
22.2 

29 
27 
29 
29 

2.44 
2.93 
1.69 
1.98 

44 
53 
30 
36 

621 
622 
623 
624 

2.35 
2.40 
2.45 
2.50 

Entrance  to  Wallabout  bay  

Midstream,  at  Williamsburg  Bridge. . . 
Midstream,  at  Williamsburg  Bridge. . . 
Midstream,  at  Williamsburg  Vridge. . . 

40  42  30 
40  42  49 
40  42  49 
40  42  49 

73  58  15 
73  58  21 
73  58  21 
73  58  21 

30 
1 

15 

30 

Ebb 
Ebb 
Ebb 
Ebb 

22.2 
22.2 
21.7 
21.7 

23 
31 
29 
29 

2  05 
1.84 
2.95 
1.96 

36 
33 
54 
36 

625 
626 
627 
628 

3  10 
3.15 
3.20 
3.35 

Midstream,  opposite  23d  street  

Midstream,  opposite  23d  street  

Midstream,  opposite  23d  street  

Opposite  42d  street  

40  44  00 
40  44  00 
40  44  00 
40  44  50 

73  58  05 
73  58  05 
73  58  05 
73  57  55 

1 
15 
30 

1 

Ebb 
Ebb 
Ebb 
Ebb 

21.7 
21.1 
21.0 
20.6 

29 
30 
28 
26 

2.35 
2.15 
2.41 
2.93 

43 
39 
43 
53 

629 
630 
631 

3.40 
3.45 
4.15 

Opposite  42d  street  

Opposite  42d  street  

Blackwells  Island  Bridge  

40  44  50 
40  44  50 
40  45  25 

73  57  55 
73  57  55 
73  57  30 

15 
30 
1 

Ebb 
Ebb 
Ebb 

20.6 
20.0 
20.0 

26 
24 
24 

2.58 
2.32 
1.65 

46 
41 
30 

682  DATA  RELATING  TO  THE  PROTECTION  OP  THE  HARBOR 

TABLE  CXXV— Continued 


17— EAST  RIVER,  BROOKLYN  BRIDGE  TO  118TH  STREET.    JULY  7,  1913— Continued 


Sample 
No. 

Hour 
P.  M. 

Location  of  Samples 

Feet 
below 
surface 

Tidal 
current 

Temp, 
water 
Deg.  C. 

Per 

cent, 
land 
water 

Ox; 

C.  C. 
per 
litre 

fgen 

Per 
cent, 
satura- 
tion 

Approximate 

Latitude 

Longitude 

A39 

633 
634 
635 

A  90 

4.25 
4.55 
5.00 

Blackwells  Island  Bridge  

Blackwells  Island  Bridge  

At  Mill  Rock  

At  Mill  Rock  

O        /  V 

40  45  25 
40  45  25 
40  46  50 
40  46  50 

O        /  V 

73  57  30 
73  57  30 
73  56  25 
73  56  25 

10 

30 
1 
15 

Ebb 
Ebb 
Ebb 

90  o 
20.0 
19.4 
18.8 

94 

24 
23 
23 

9  AA 

& .  oo 
2.56 
3.23 
3.92 

A  Q 

44 
57 
69 

636 
637 
638 
639 

5.05 
5.12 
5.20 
5.25 

At  Mill  Rock  

Harlem  river,  109th  street  

Harlem  river,  109th  street  

Harlem  river,  109th  street  

40  46  50 
40  47  23 
40  47  23 
40  47  23 

73  56  25 
73  56  07 
73  56  07 
73  56  07 

30 
1 
15 
25 

Ebb 
Ebb 
Ebb 
Ebb 

18.8 
19.4 
19.4 
19.4 

23 
23 
19 
27 

3.07 
2.90 
3.06 
2.94 

54 
51 
55 
51 

640 
641 
642 

5.35 
5.40 
5.45 

Harlem  river,  1 18th  street  

Harlem  river,  118th  street  

Harlem  river,  118th  street  

40  47  41 
40  47  41 
40  47  41 

73  55  44 
73  55  44 
73  55  44 

1 
12 
20 

Ebb 
Ebb 
Ebb 

20.6 
19.4 
19.4 

24 
22 
19 

1.25 
2.47 
1.84 

20 
44 

32 

18— EAST  RIVER,  CROSS-SECTION,  LAWRENCE  POINT.    JULY  8,  1913 

Low  water  occurred  at  Governors  Islanp  at  7.30  A.  M.    High  water  at  1.20  P.  M.    The  wind  was  northwest,  with  a  velocity 
of  3  miles  per  hour. 

643 
644 
645 
646 

A.  M. 
7.00 
7.03 
7.06 
7.10 

Lawrence  Point,  near  black  buoy  

Lawrence  Point,  near  black  buoy  

Lawrence  Point,  near  black  buoy  

Mid-channel  

40  47  34 
40  47  34 
40  47  34 
40  47  25 

73  54  30 
73  54  30 
73  54  30 
73  54  31 

1 

21 
40 
1 

Flood 
Flood 
Flood 
Flood 

18.9 
18.3 
18.0 
18.0 

22 
22 
22 
22 

2.55 
3.39 
3.84 
3.39 

45 

59 
57 
59 

647 
648 
649 
650 

7.12 
7.15 
7.20 
7.25 

Mid-channel  

Mid-channel  

200  feet  off  ferry,  East  234th  street. . . 
200  feet  off  ferry,  East  234th  street.  .  . 

40  47  25 
40  47  25 
40  47  56 
40  47  56 

73  54  31 
73  54  31 
73  54  31 
73  54  31 

18 
35 
1 
15 

Flood 
Flood 
Flood 
Flood 

18.3 
18.3 
18.3 
17.8 

22 
22 
20 
22 

2.69 
3.42 
3.13 
2.66 

47 
59 
54 
46 

651 
652 
653 
654 

7.30 
8.20 
8.23 
8.25 

200  feet  off  ferry,  East  234th  street. .  . 

Lawrence  Point,  near  black  buoy  

Lawrence  Point,  near  black  buoy  

Lawrence  Point,  near  black  buoy  

40  47  56 
40  47  34 
40  47  34 
40  47  34 

73  54  31 
73  54  30 
73  54  30 
73  54  30 

30 
1 
21 
40 

Flood 
Flood 
Flood 
Flood 

17.8 
18.3 
18.3 
18.3 

20 
20 
22 
26 

2.99 
3.19 
3.29 
4.12 

51 
55 
57 
71 

655 
656 
657 
658 

8.33 
8.36 
8.40 
8.45 

Mid-channel  

Mid-channel  

Mid-channel  

200  feet  off  ferry,  East  234th  street.  . . 

40  47  25 
40  47  25 
40  47  25 
40  47  56 

73  54  31 
73  54  31 
73  54  31 
73  54  31 

1 

18 
35 
1 

Flood 
Flood 
Flood 
Flood 

18.3 
18.6 
18.6 
18.3 

24 
24 
24 
24 

4.18 
3.69 
4.41 
3.46 

72 
64 
76 
60 

659 
C60 
661 
662 

8.48 
8.55 
9.55 
10.03 

200  feet  off  ferry,  East  234th  street .  .  . 
200  feet  off  ferry,  East  234th  street .  .  . 

Lawrence  Point,  near  buoy  

Lawrence  Point,  near  buoy  

40  47  56 
40  47  56 
40  47  34 
40  47  34 

73  54  31 
73  54  31 
73  54  30 
73  54  30 

15 
30 
1 
21 

Flood 
Flood 
Flood 
Flood 

18.3 
18.3 
20.0 
20  0 

24 
24 
24 
24 

3.37 
3.03 
2.35 
2.58 

58 
52 
42 
46 

663 
664 
665 
666 

10. 0G 
10.10 
10.15 
10.20 

Lawrence  Point,  near  buoy  

Mid-channel  

Mid-channel  

Mid-channel  

40  47  34 
40  47  25 
40  47  25 
40  47  25 

73  54  30 
73  54  31 
73  54  31 
73  54  31 

40 
1 

18 
35 

Flood 
Flood 
Flood 
Flood 

18.9 
20.0 
19.4 
19.4 

30 
24 
30 
30 

2.88 
2.62 
1.88 
2.14 

41 
47 
33 
37 

667 
668 
669 
670 

10.25 
10.30 
10.35 
11.50 

200  feet  off  ferry  house,  E.  234th  st. . . 
200  feet  off  ferry  house,  E.  234th  st. . . 
200  feet  off  ferry  house,  E.  234th  st. . . 
Lawrence  Point,  near  black  buoy  

40  47  56 
40  47  56 
40  47  56 
40  47  34 

73  54  31 
73  54  31 
73  54  31 
73  54  30 

1 
15 
30 

1 

Flood 
Flood 
Flood 
Flood 

19.7 
19.7 
19.7 
21.1 

24 
30 
30 
30 

2.17 
1.84 

2.83 
1.48 

38 
32 
49 
26 

671 

672 

673 
674 

11.55 
12.00 
P.  M. 
12.05 
12.08 

Lawrence  Point,  near  black  buoy  

Lawrence  Point,  near  black  buoy  

40  47  34 
40  47  34 

40  47  25 
40  47  25 

73  54  30 
73  54  30 

73  54  31 
73  54  31 

21 
40 

1 
18 

Flood 
Flood 

Flood 
Flood 

21.4 
21.7 

21.7 
22.2 

30 
30 

30 
29 

1.38 
1.75 

1.97 
1.37 

25 
32 

36 
25 

DISSOLVED  OXYGEN  IN  THE  WATER 


683 


TABLE  CXXV— Continued 


18— EAST  RIVER,  CROSS-SECTION,  LAWRENCE  POINT.    JULY  8,  1913— Continued 


Sample 
No. 

Hour 
P.  M. 

Location  of  Samples 

Feet 
below 
surface 

Tidal 
current 

Temp, 
water 
ueg.  kj. 

Per 
cent, 
land 
water 

Ox; 

C.  C. 
per 
litre 

fgen 

Per 
cent, 
satura- 
tion 

Approximate 

Latitude 

Longitude 

675 
676 
677 
678 

12.11 
12.15 
12.20 
12.25 

Mid-channel 

200  feet  off  ferry  house,  E.  234th  st. . . 
200  feet  off  ferry  house,  E.  234th  st. . . 
200  feet  off  ferry  house,  E.  234th  st. . . 

0      /  a 

40  47  25 
40  47  56 
40  47  56 
40  47  56 

0      /  r 

73  54  31 
73  54  31 
73  54  31 
73  54  31 

35 
1 
15 

30 

Flood 
Flood 
Flood 
Flood 

21.7 
22.8 
22.8 
21.7 

33 
32 
32 
30 

2.26 
2.20 
1.63 
2.74 

47 
47 
32 
51 

679 
680 
681 
682 

1.53 
1.56 
2.00 
2.05 

Lawrence  Point  near  buoy 

Lawrence  Point,  near  buoy  

Lawrence  Point,  near  buoy  

Mid-channel  

40  47  34 
40  47  34 
40  47  34 
40  47  25 

73  54  30 
73  54  30 
73  54  30 
73  54  31 

1 

21 
40 
1 

Ebb 
Ebb 
Ebb 
Ebb 

21.7 
21.7 
21.7 
22.0 

32 
32 
29 
32 

1.74 
1.78 
2.52 
2.13 

31 

32 
45 
38 

683 
684 
685 
686 

2.10 
2.15 
2.20 
2.25 

Mid-channel 

Mid-channel  

200  feet  off  ferry  house,  E.  234th  st. . . 
200  feet  off  ferry  house,  E.  234th  st. . . 

40  47  25 
40  47  25 
40  47  56 
40  47  56 

73  54  31 
73  54  31 
73  54  31 
73  54  31 

18 
35 
1 
15 

Ebb 
Ebb 
Ebb 
Ebb 

21.7 
21.7 
21.7 
21.7 

32 
32 
32 
25 

1.87 
1.67 
1.85 
1.62 

34 
30 
34 
30 

687 
688 
689 
690 

2.30 
4.08 
4.15 
4.17 

200  feet  off  ferry  house,  E.  234th  st. . . 

Lawrence  Point,  near  buoy  

Lawrence  Point,  near  buoy  

40  47  56 
40  47  34 
40  47  34 
40  47  34 

73  54  31 
73  54  30 
73  54  30 
73  54  30 

30 
1 
21 
40 

Ebb 
Ebb 
Ebb 
Ebb 

21.4 

20.0 
20.0 
20.0 

25 
25 
25 
25 

1.95 
2.85 
2.79 
2.48 

35 
50 
48 
44 

691 
692 
693 
694 

4.20 
4.25 
4.30 
4.37 

if-j  _t  i 

Mid-channel  

Mid-channel  

200  feet  off  ferry,  East  234th  street . . . 

40  47  25 
40  47  25 
40  47  25 
40  47  56 

73  54  31 
73  54  31 
73  54  31 
73  54  31 

1 

18 
35 
1 

Ebb 
Ebb 
Ebb 
Ebb 

19.7 
19.7 
19.7 
19.1 

22 
22 
22 
22 

2.99 
2.99 
3.11 
2.93 

53 
53 
55 
51 

695 
696 
697 

698 

4.40 
4^45 
5.25 
5.30 

200  feet  off  ferry,  East  234th  street . . . 
200  feet  off  ferry,  East  234th  street. . . 

Lawrence  Point,  near  buoy  

Lawrence  Point,  near  buoy  

40  47  56 
40  47  56 
40  47  34 
40  47  34 

73  54  31 
73  54  31 
73  54  30 
73  54  30 

15 
30 
1 
21 

Ebb 
Ebb 
Ebb 
Ebb 

19  4 
19^4 
18.9 
19.4 

22 
22 
26 
22 

3.68 
3^42 
2.55 
2.89 

65 
60 
44 
51 

699 
700 
701 
702 

5.35 
5.40 
5.43 
5.45 

Lawrence  Point,  near  buoy  

Mid-channel  

Mid-channel  '.  

40  47  34 
40  47  25 
40  47  25 
40  47  25 

73  54  30 
73  54  31 
73  54  31 
73  54  31 

40 
1 
15 
30 

Ebb 
Ebb 
Ebb 
Ebb 

19.2 
19.2 
19.2 
18.9 

19 

23 
23 
23 

3.66 
3.77 
4.20 
3.49 

65 
66 
73 
60 

703 
704 
705 

5.52 
5.55 
5.59 

200  feet  off  ferry,  East  234th  street . . . 
200  feet  off  ferry,  East  234th  street. .  . 
200  feet  off  ferry,  East  234th  street . . . 

40  47  56 
40  47  56 
40  47  56 

73  54  31 
73  54  31 
73  54  31 

1 

15 
30 

Ebb 
Ebb 
Ebb 

18.9 
18.9 
18.9 

23 
23 
22 

3.43 
3.42 
3.42 

60 
60 
60 

19— HUDSON  RIVER,  CROSS-SECTION,  PIER  A  TO  C.  R.R.  OF  N.  J.  PIER.    JULY  9,  1913 

Low  water  occurred  at  Governors  Island  at  8.30  A.  M.    High  water  at  2.45  P.  M.    The  wind  was  southwest,  with  a  velocity 
of  3  miles  per  hour. 

706 
707 
708 
709 

A.  M. 
7.10 
7.15 
7.20 
7.25 

100  feet  off  Pier  A  

100  feet  off  Pier  A  

100  feet  off  Pier  A  

\i  way  across  

40  42  16 
40  42  16 
40  42  16 
40  42  17 

74  01  09 
74  01  09 
74  01  09 
74  01  20 

1 

18 
30 
1 

Flood 
Flood 
Flood 
Flood 

21.7 
21.7 
21.1 
21.7 

27 
27 
27 
27 

2.63 
2.41 
2.66 
2.60 

48 
53 
49 
47 

710 
711 
712 
713 

7.30 
7.35 
7.38 
7.42 

l/i  way  across  

}/£  way  across  

l/2  way  across  

40  42  17 
40  42  17 
40  42  19 
40  42  19 

74  01  20 
74  01  20 
74  01  34 
74  01  34 

18 
30 
1 
18 

Flood 
Flood 
Flood 
Flood 

21.7 
21.7 
21.7 
21.7 

29 
32 
33 
32 

2.21 
1.97 
2.19 
1.97 

39 
36 
39 
36 

714 
715 
716 
717 

7.46 
7.49 
7.53 
7.58 

Y2  way  across  

%  way  across  

%  way  across  

40  42  19 
40  42  21 
40  42  21 
40  42  21 

74  01  34 
74  01  48 
74  01  48 
74  01  48 

42 
1 
18 
42 

Flood 
Flood 
Flood 
Flood 

21.7 
21.9 
21.9 
21.7 

32 
33 
33 
33 

2.04 
2.22 
2.48 
2.36 

37 
40 
45 
43 

718 
719 
720 

8.00 
8.05 
8.10 

100  feet  off  C.  R.R.  of  N.  J.  pier. 
100  feet  off  C.  R.R.  of  N.  J.  pier 
100  feet  off  C.  R.R.  of  N.  J.  pier 

40  42  22 
40  42  22 
40  42  22 

74  01  59 
74  01  59 
74  01  59 

1 

18 
30 

Flood 
Flood 
Flood 

21.9 
21.1 
21.1 

35 
35 
34 

2.28 
2.60 
2.40 

41 

46 
42 

684 


DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


TABLE  CXXV— Continued 


19— HUDSON  RIVER,  CROSS-SECTION,  PIER  A  TO  C.  R.R.  OF  N.  J.  PIER.    JULY  9,  1913— Continued 


Sample 
No. 

Hour 

A.  M. 

Location  of  Samples 

Feet 
below 
surface 

Tidal 
current 

Temp, 
water 
ijeg. 

Per 
cent, 
land 
water 

Ox; 

C.  C. 
per 
litre 

fgen 

Per 
cent, 
satura- 
tion 

Approximate 

Latitude 

Longitude 

721 

722 
723 
724 

9.30 
9.35 
9.38 
9.42 

100  feet  off  Pier  A  

100  feet  off  Pier  A  

100  feet  off  Pier  A  

Y  way  across  

O         t  If 

40  42  16 
40  42  16 
40  42  16 
40  42  17 

OIK 

74  01  09 
74  01  09 
74  01  09 
74  01  20 

1 

18 
30 
1 

Flood 
Flood 
Flood 
Flood 

22.2 
21.7 
21.1 
21.9 

35 
33 
28 
33 

2.26 
2.20 
2.33 
2.21 

40 
40 
42 
40 

725 
726 
727 
728 

9.45 
9.50 
9.55 
10.00 

Y  way  across  

Y  way  across  

Yi  way  across  

Yi  way  across  

40  42  17 
40  42  17 
40  42  19 
40  42  19 

74  01  20 
74  01  20 
74  01  34 
74  01  34 

18 
30 
1 

18 

Flood 
Flood 
Flood 
Flood 

21.9 
21.7 
22.2 
21.7 

33 
32 
35 
35 

1.81 
1.89 
2.41 
2.38 

33 
34 
44 
43 

729 
730 
731 
732 

10.05 
10.08 
10.10 
10.15 

Yi  way  across  

%  way  across  

Y  way  across  

Y  way  across  

40  42  19 
40  42  21 
40  42  21 
40  42  21 

74  01  34 
74  01  48 
74  01  48 
74  01  48 

42 
1 
18 

42 

Flood 
Flood 
Flood 
Flood 

21.1 

22.2 
21.7 
21.7 

32 
35 
35 
32 

2.04 
2.23 
2.78 
2.67 

37 
40 
50 
48 

733 
734 
735 
736 

10.20 
10  25 
10.30 
11.25 

100  feet  off  C.  R.R.  of  N.  J.  pier 
100  feet  off  C.  R.R.  of  N.  J.  pier 
100  feet  off  C.  R.R.  of  N.  J.  pier 
100  feet  off  Pier  A  

40  42  22 
40  42  22 
40  42  22 
40  42  16 

74  01  59 
74  01  59 
74  01  59 
74  01  09 

1 

18 
30 
1 

Flood 
Flood 
Flood 
Flood 

21.9 
21.9 
21.9 
22.2 

33 
32 
32 
33 

2.39 
2.20 
2.74 
2.76 

43 
40 
50 
50 

737 
738 
739 
740 

11.30 
11.33 
11.35 
11.37 

100  feet  off  Pier  A  

100  feet  off  Pier  A  

Y  way  across  

Y  way  across  

40  42  16 
40  42  16 
40  42  17 
40  42  17 

74  01  09 
74  01  09 
74  01  20 
74  01  20 

18 
30 
1 
18 

Flood 
Flood 
Flood 
Flood 

21.7 
21.1 
21.7 
21.7 

32 
30 
35 
32 

2.03 
2.35 
2.12 
2.02 

37 
42 
38 
36 

741 
742 
743 
744 

11.42 
11.47 
11.50 
11.55 

Y  way  across  

Yi  way  across  

Yi  way  across  

Yi  way  across  

40  42  17 
40  42  19 
40  42  19 
40  42  19 

74  01  20 
74  01  34 
74  01  34 
74  01  34 

30 
1 
18 
42 

Flood 
Flood 
Flood 
Flood 

21.4 
21.7 
21.7 
20.8 

30 
32 
32 
30 

1.39 
2.35 
2.37 
1.94 

25 
42 
43 
34 

745 

746 
747 
748 

12.00 
P.  M. 
12.05 
12.07 
12.10 

Y  way  across  

Y  way  across  

Y  way  across  

100  feet  off  C.  R.R.  of  N.  J.  pier 

40  42  21 

40  42  41 
40  42  21 
40  42  22 

74  01  48 

74  01  48 
74  01  48 
74  01  59 

1 

18 
42 
1 

Ebb 

Ebb 
Ebb 
Ebb 

21.7 

21.7 
21.4 
21.7 

32 

32 
30 
32 

2.65 

2.70 
2.80 
2.05 

46 

48 
52 
37 

749 
750 
751 
752 

12.15 
12.20 
1.35 
1.40 

100  feet  off  C.  R.R.  of  N.  J.  pier 
100  feet  off  C.  R.R.  of  N.  J.  pier 

100  feet  off  Pier  A  

100  feet  off  Pier  A  

40  42  22 
40  42  22 
40  42  16 
40  42  16 

74  01  59 
74  01  59 
74  01  09 
74  01  09 

18 
30 
1 
18 

Ebb 
Ebb 
Ebb 
Ebb 

21.7 
21.7 
21.1 
20.8 

30 
30 
24 
24 

2.36 
2.56 
2.93 
3.23 

43 
46 
53 
58 

753 
754 
755 
756 

1.45 
1.50 
1.53 
1.56 

100  feet  off  Pier  A  

Y  way  across  

Y  way  across  

Y  way  across  

40  42  16 
40  42  17 
40  42  17 
40  42  17 

74  01  09 
74  01  20 
74  01  20 
74  01  20 

30 
1 
18 
30 

Ebb 
Ebb 
Ebb 
Ebb 

20.3 
21.4 
20.8 
20.0 

21 
27 
24 
19 

2.93 
3.90 
3.31 
3.31 

53 
71 
59 
59 

757 
758 
759 
760 

2.05 
2.10 
2.12 
2.20 

Yi  way  across 

Yi  way  across  

Yt  way  across  

%  way  across  

40  42  19 
40  42  19 
40  42  19 
40  42  21 

74  01  34 
74  01  34 
74  01  34 
74  01  48 

1 

18 
42 
1 

Ebb 
Ebb 
Ebb 
Ebb 

21.4 
20.8 
20.3 
21.7 

26 
24 
19 
27 

3.08 
3.25 
3.95 
3.29 

50 
59 
71 
60 

761 
762 
763 
764 

2.24 
2.30 
2.35 
2.40 

Y  way  across  

Y  way  across  

100  feet  off  C.  R.R.  of  N.  J.  pier 

100  feet  off  C.  R.R.  of  N.  J.  pier 

40  42  21 
40  42  21 
40  42  22 
40  42  22 

74  01  48 
74  01  48 
74  01  59 
74  01  59 

18 
42 
1 
18 

Ebb 
Ebb 
Ebb 
Ebb 

20.8 
20.3 
21.7 
21.4 

26 
21 
29 
32 

3.46 
3.91 
2.79 
3.00 

62 
70 
51 
54 

765 
766 
767 
768 

2.45 
4.00 
4.03 
4.08 

100  feet  off  C.  R.R.  of  N.  J.  pier 

100  feet  off  Pier  A  

100  feet  off  Pier  A  

100  feet  off  Pier  A  

40  42  22 
40  42  16 
40  42  16 
40  42  16 

74  01  59 
74  01  09 
74  01  09 
74  01  09 

30 
1 
18 
30 

Ebb 
Ebb 
Ebb 
Ebb 

20.6 
21.1 
20.8 
21.1 

30 
32 
24 
24 

3.95 
3.91 
3.29 
3.55 

70 
70 
59 
63 

769 
770 
771 

4.10 
4.15 
4.18 

Y  way  across  

Y  way  across  

Y  way  across  

40  42  17 
40  42  17 
40  42  17 

74  01  20 
74  01  20 
74  01  20 

1 
18 
30 

Ebb 
Ebb 
Ebb 

20.6 
20.6 
21.1 

24 
24 
22 

3.86 
3.46 
3.75 

70 
62 
67 

DISSOLVED  OXYGEN  IN  THE  WATER  685 
TABLE  CXXV— Continued 


19— HUDSON  RIVER,  CROSS-SECTION,  PIER  A  TO  C.  R.R.  OF  N.  J.  PIER.    JULY  9,  1913— Continued 


Sample 
No. 

Hour 
P.  M. 

Location  of  Samples 

Feet 
below 
surface 

Tidal 
current 

Temp, 
water 
Deg.  C. 

Per 

cent, 
land 
water 

c.  c. 

per 
litre 

fgen 

Per 

cent, 
satura- 
tion 

Approximate 

Latitude 

Longitude 

772 
773 
774 
775 

4  22 
4'25 
4.30 
4.33 

Yi  way  across  

%  way  across  

O  / 
A  l\  A  o  in 

4U  a  la 
40  42  19 
40  42  19 
40  42  21 

o      /  w 

•7  A    A1  A 

/4  Ul  61 

74  01  34 
74  01  34 
74  01  48 

1 

18 
42 
1 

Ebb 
Ebb 
Ebb 
Ebb 

20  8 
20.8 
21.1 
21.1 

26 
24 
26 
28 

2  86 
3.16 
2.57 
3.09 

52 
57 
46 
55 

776 
777 
778 
779 

4  36 
4'38 
4.40 
4.45 

%  way  across  

100  feet  off  C.  R.R.  of  N.  J.  pier 
100  feet  off  C.  R.R.  of  N.  J.  pier 

A(\     AC\  cy\ 

4U  4Z  Zl 

40  42  21 
40  42  22 
40  42  22 

il  UI  48 

74  01  48 
74  01  59 
74  01  59 

18 
42 
1 
18 

Ebb 
Ebb 
Ebb 
Ebb 

21 . 1 
20.6 
21.1 
21.1 

26 
24 
26 
26 

3  03 
2.74 
2.08 
2.70 

55 
50 
38 
48 

780 
781 
782 
783 

4  50 

5^35 
5.38 
5.40 

100  feet  off  C.  R.R.  of  N.  J.  pier 

100  feet  off  Pier  A  

100  feet  off  Pier  A  

100  feet  off  Pier  A  

40  42  22 
40  42  16 
40  42  16 
40  42  16 

74  01  59 
74  01  09 
74  01  09 
74  01  09 

30 
1 
18 
30 

Ebb 
Ebb 
Ebb 
Ebb 

20  6 
21.1 
21.1 
21.1 

24 
28 
28 
28 

3  22 
3.49 
3.83 
3.46 

57 
63 
69 
62 

784 
785 
786 
787 

5.45 
5.47 
5.50 
5.55 

%  way  across  

l/i  way  across  

\i  way  across  

}/2  way  across  

40  42  17 
40  42  17 
40  42  17 
40  42  19 

74  01  20 
74  01  20 
74  01  20 
74  01  34 

1 
18 
30 

1 

Ebb 
Ebb 
Ebb 
Ebb 

21.1 
20.8 
20.8 
21.1 

28 
26 
26 
28 

2.41 
2.71 
2.31 

3.25 

53 
49 
41 
58 

788 
789 
790 
791 

5.58 
6.00 
6.05 
6.07 

H  way  across  

%  way  across  

s/i  way  across  

%  way  across  

40  42  19 
40  42  19 
40  42  21 
40  42  21 

74  01  34 
74  01  34 
74  01  48 
74  01  48 

18 
42 
1 
18 

Ebb 
Ebb 
Ebb 
Ebb 

21.1 
20.6 
21.1 
21.1 

28 
24 
28 
28 

2.74 
2.46 
2.09 
3.02 

49 
44 
38 
54 

792 
793 
794 
795 

6.10 
6.20 
6.22 
6.25 

3/i  way  across  

100  feet  off  C.  R.R.  of  N.  J.  pier 
100  feet  off  C.  R.R.  of  N.  J.  pier 
100  feet  off  C.  R.R.  of  N.  J.  pier 

40  42  21 
40  42  22 
40  42  22 
40  42  22 

74  01  48 
74  01  59 
74  01  59 
74  01  59 

42 
1 
18 
30 

Ebb 
Ebb 
Ebb 
Ebb 

20.6 
20.8 
20.8 
20.6 

24 
26 
26 
20 

2.42 
2.40 
2.90 
2.84 

43 
43 
52 
51 

20— ROBBINS  REEF.    JULY  10,  1913 


High  water  occurred  at  Governors  Island  at  4.10  P.  M.  Low  water  at  9.30  A.  M.  The  wind  was  west,  with  a  velocity  of  5 
miles  per  hour. 


796 
797 
798 
799 

A.  M. 
7.20 
7.25 
7.30 
8.20 

Near  bell  buoy  

Near  bell  buoy  

Near  bell  buoy  

Near  bell  buoy  

40  39  15 
40  39  15 
40  39  15 
40  39  15 

74  03  50 
74  03  50 
74  03  50 
74  03  50 

1 

24 
48 
1 

Flood 
Flood 
Flood 
Flood 

20.8 
20.6 
20.6 
20.8 

24 
27 
25 
26 

3.16 
3.13 
3.61 
2.80 

57 
56 
65 
50 

800 
801 

802 
803 

8.25 
8.30 
9.05 
9.10 

Near  bell  buoy  

Near  bell  buoy  

Near  bell  buoy  

Near  bell  buoy  

40  39  15 
40  39  15 
40  39  15 
40  39  15 

74  03  50 
74  03  50 
74  03  50 
74  03  50 

24 
48 
1 
24 

Flood 
Flood 
Flood 
Flood 

20  8 
20.6 
21.1 
21.1 

24 
20 
26 
26 

2.90 
3.00 
2  50 
3.20 

52 
54 
45 
57 

804 
805 
806 
807 

9.15 
11.00 
11.10 
11.15 

Near  bell  buoy  

Near  bell  buoy  

Near  bell  buoy  

Near  bell  buoy  

40  39  15 
40  39  15 
40  39  15 
40  39  15 

74  03  50 
74  03  50 
74  03  50 
74  03  50 

48 
1 
24 
48 

Flood 
Flood 
Flood 
Flood 

20.6 
20.8 
20.6 
19.4 

24 
22 
20 
15 

3.20 
2.50 
2.60 
3.80 

57 
45 
46 
69 

808 
809 
810 
811 

P.  M. 
1.00 
1.05 
1.10 
1.55 

Near  bell  buoy  

Near  bell  buoy  

Near  bell  buoy  

Near  bell  buoy  

40  39  15 
40  39  15 
40  39  15 
40  39  15 

74  03  50 
74  03  50 
74  03  50 
74  03  50 

1 

28 
48 
1 

Flood 
Flood 
Flood 
Ebb 

20.6 
19.7 
19.7 
20.8 

18 
17 
17 
16 

2.60 
3.90 
4.10 
4.30 

47 
70 
74 
79 

812 
813 
814 
815 

2.00 
2.05 
3.00 
3.05 

Near  bell  buoy  

Near  bell  buoy  

Near  bell  buoy  

Near  bell  buoy  

40  39  15 
40  39  15 
40  39  15 
40  39  15 

74  03  50 
74  03  50 
74  03  50 
74  03  50 

24 
48 
1 
24 

Ebb 
Ebb 
Ebb 
Ebb 

20.0 
19.7 
20.6 
19.7 

16 
15 
16 
15 

4.40 
4.10 
4.30 
4.30 

80 
74 
79 
77 

686  DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

TABLE  CXXV— Continued 


20— ROBBINS  REEF.    JULY  10,  1913— Continued 


Sample 
No. 

Hour 
P.  M. 

Location  of  Samples 

Feet 
below 
surface 

Tidal 
current 

Temp. 
wSiter 
Deg.  C. 

Per 

cent, 
land 
water 

C.  C! 
per 
litre 

rgen 

Per 
cent, 
satura- 
tion 

Approximate 

Latitude 

Longitude 

816 
817 
818 
819 

3.10 
4.00 
4.05 
4.10 

Near  bell  buoy  

Near  bell  buoy  

Near  bell  buoy  

Near  bell  buoy  

p     /  n 

40  39  15 
40  39  15 
40  39  15 
40  39  15 

o      t  V 

74  03  50 
74  03  50 
74  03  50 
74  03  50 

48 
1 

24 
48 

Ebb 
Ebb 
Ebb 
Ebb 

19.7 
20.6 
20.3 
19.7 

15 
16 
16 
15 

4.40 
4.30 
4.80 
4.60 

80 
79 
88 
82 

820 
821 
822 

5.50 
5.55 
6.00 

Near  bell  buoy  

Near  bell  buoy  

Near  bell  buoy  

40  39  15 
40  39  15 
40  39  15 

74  03  50 
74  03  50 
74  03  50 

1 

24 
48 

Ebb 
Ebb 
Ebb 

21.1 
20.0 
20.0 

15 
15 
13 

4.20 
4.60 
4.70 

78 
83 
86 

21— KILL  VAN  KULL,  CROSS-SECTION,  SAILORS  SNUG  HARBOR.    JULY  11,  1913 

Low  water  occurred  at  Governors  Island  at  10.30  A.  M.    High  water  at  3.00  P.  M.    The  wind  was  northwest,  with  a  velocity 
of  3  miles  per  hour. 

823 
824 
825 
826 

A.  M. 
7.30 
7.35 
7.40 
7.45 

200  feet  off  Sailors  Snug  Harbor  

200  feet  off  Sailors  Snug  Harbor  

200  feet  off  Sailors  Snug  Harbor  

Midstream  

A  f\    o  ft     A  r* 

40  38  46 
40  38  46 
40  38  46 
40  38  51 

74  06  09 
74  06  09 
74  06  09 
74  06  08 

1 
15 
24 

1 

Ebb 
Ebb 
Ebb 
Ebb 

21 . 1 
21.1 
21.1 
21.1 

28 
28 
30 
30 

3.40 
4.10 
3.50 
3.98 

61 
74 
63 
71 

827 

828 
829 
830 

7.50 
7.55 
8.00 
8.05 

Midstream  

Midstream  

200  feet  off  Bayonne  shore  

200  feet  off  Bayonne  shore  

40  38  51 
40  38  51 
40  38  55 
40  38  55 

74  06  08 
74  06  08 
74  06  07 
74  06  07 

15 
30 
1 
15 

Ebb 
Ebb 
Flood 
Flood 

21.1 
21.1 
20.8 
21.1 

30 
30 
30 
28 

3  40 
3.37 
4.11 
3.73 

61 
60 
73 
67 

831 

832 
833 
834 

8.10 
9.05 
9.08 
9.12 

200  feet  off  Bayonne  shore  

200  feet  off  Sailors  Snug  Harbor  

200  feet  off  Sailors  Snug  Harbor  

200  feet  off  Sailors  Snug  Harbor  

40  38  55 
40  38  46 
40  38  46 
40  38  46 

74  06  07 
74  06  09 
74  06  09 
74  06  09 

24 
1 
15 
24 

Flood 
Flood 
Flood 
Flood 

21.7 
21.7 
21.4 
21.7 

30 
32 
29 
29 

4.09 
4.10 
3.80 
3.80 

73 
74 
69 
69 

835 
836 
837 
838 

9.19 
9.22 
9.30 
9.35 

Midstream  

Midstream  

Midstream  

200  feet  off  Bayonne  shore  

40  38  51 
40  38  51 
40  38  51 
40  38  55 

74  06  08 
74  06  08 
74  06  08 
74  06  07 

1 

15 
30 
1 

Flood 
Flood 
Flood 
Flood 

21.7 
21.7 
21.7 
21.7 

32 
29 
29 
29 

3.98 
3.90 
3.99 
4.20 

71 

70 
72 
76 

839 
840 
841 
842 

9.38 
9.45 
11.00 
11.05 

200  feet  off  Bayonne  shore  

200  feet  off  Bayonne  shore  

200  feet  off  Sailors  Snug  Harbor  

200  feet  off  Sailors  Snug  Harbor  

40  38  55 
40  38  55 
40  38  46 
40  38  46 

74  06  07 
74  06  07 
74  06  09 
74  06  09 

15 
24 
1 
15 

Flood 
Flood 
Flood 
Flood 

21.9 
21.7 
21.7 
21.7 

29 
29 
25 
24 

3.54 
4.09 
3.10 
3.40 

64 
74 
57 
62 

843 
844 
845 
846 

11.08 
11.10 
11.17 
11.20 

200  feet  off  Sailors  Snug  Harbor  

Midstream  

Midstream  

Midstream  

40  38  46 
40  38  51 
40  38  51 
40  38  51 

74  06  09 
74  06  08 
74  06  08 
74  06  08 

24 
1 
15 
30 

Flood 
Flood 
Flood 
Flood 

21.4 
21.7 
21.1 
21.7 

25 
28 
28 
28 

3.40 
3.19 
2.99 
3.24 

62 
58 
54 
58 

847 
848 
849 

850 

11.25 
11.30 
11.35 
P.  M. 
1.00 

200  feet  off  Bayonne  shore  

200  feet  off  Bayonne  shore  

200  feet  off  Sailors  Snug  Harbor  

40  38  55 
40  38  55 
40  38  55 

40  38  46 

74  06  07 
74  06  07 
74  06  07 

74  06  09 

1 

15 
24 

1 

Flood 
Flood 
Flood 

Flood 

21.7 
21.7 
21.7 

21.9 

27 
27 
27 

29 

3.46 
3.02 
3.75 

3.00 

63 
55 
68 

55 

851 
852 
853 
854 

1.05 
1.10 
1.15 
1.18 

200  feet  off  Sailors  Snug  Harbor  

200  feet  off  Sailors  Snug  Harbor  

Midstream  

Midstream  

40  38  46 
40  38  46 
40  38  51 
40  38  51 

74  06  09 
74  06  09 
74  06  08 
74  06  08 

15 
24 
1 
15 

Flood 
Flood 
Flood 
Flood 

21.4 
21.7 
21.7 
21.1 

29 
25 
29 
28 

3.30 
3.80 
3.19 
3.30 

60 
69 
55 
60 

855 
856 
857 
858 
859 

1.20 
1.25 
1.28 
1.30 
2.10 

Midstream  

200  feet  off  Bayonne  shore  

200  feet  off  Bayonne  shore  

200  feet  off  Bayonne  shore  

200  feet  off  Sailors  Snug  Harbor  

40  38  51 
40  38  55 
40  38  55 
40  38  55 
40  38  46 

74  06  08 
74  06  07 
74  06  7 
74  06  07 
74  06  09 

30 
1 
15 
24 
1 

Flood 
Flood 
Flood 
Flood 
Ebb 

20.6 
21.7 
21.1 
20.6 
21.1 

24 
27 
25 
24 
26 

3.14 
3.43 
3.30 
3.93 
3.30 

56 
62 
60 
70 
59 

DISSOLVED  OXYGEN  IN  THE  WATER 


687 


TABLE  CXXV— Continued 


21— KILL  VAN  KULL,  CROSS-SECTION,  SAILORS  SNUG  HARBOR.    JULY  11,  1913— Continued 


Sample 
No. 

Hour 
P.  M. 

Location  of  Samples 

Feet 
below 

sUTIatC 

Tidal 
current 

Temp, 
water 
ueg.  kj. 

Per 
cent, 
land 
water 

Ox; 
c.  c. 

per 
litre 

fgen 

Per 

cent, 
fatura- 
tion 

Approximate 

Latitude 

Longitude 

860 
861 
862 
863 

2.12 
2.15 
2.25 
2.30 

200  feet  off  Sailors  Snue  Harbor 

200  feet  off  Sailors  Snug  Harbor  

Mid-channel  

O        /  9 

40  38  46 
40  38  46 
40  38  51 
40  38  51 

Oft 

74  06  09 
74  06  09 
74  06  08 
74  06  08 

15 
24 
1 
15 

Ebb 
Ebb 
Ebb 
Ebb 

20.6 
20.6 
21.1 
20.6 

22 
22 
26 
20 

3.70 
3.70 
3.47 
3.80 

66 
66 
62 
69 

864 
865 
866 
867 

2.33 
2.36 
2.38 
2.40 

\T  id-channel 

200  feet  off  Bayonne  shore  

200  feet  off  Bayonne  shore  

200  feet  off  Bayonne  shore  

40  38  51 
40  38  55 
40  38  55 
40  38  55 

74  06  08 
74  06  07 
74  06  07 
74  06  07 

30 
1 
15 
24 

Ebb 
Ebb 
Ebb 
Ebb 

20.0 
21.1 
20.6 
20.0 

21 

26 
24 
24 

4.27 
4.01 
3.33 
3.70 

76 
70 
60 
66 

868 
869 
870 
871 

3.15 
3.17 
3.20 
3.25 

200  feet  off  Sailors  Snug  Harbor 

200  feet  off  Sailors  Snug  Harbor  

200  feet  off  Sailors  Snug  Harbor  

Mid-channel  

40  38  46 
40  38  46 
40  38  46 
40  38  51 

74  06  09 
74  06  09 
74  06  09 
74  06  08 

1 

15 
24 
1 

Ebb 
Ebb 
Ebb 
Ebb 

20.3 
20.0 
20.0 
20.6 

18 
17 
18 
20 

3.80 
3.70 
3.60 
3.69 

70 
67 
65 
66 

872 
873 
874 
875 

3.30 
3.35 
3.40 
3.45 

Mid-channpl 

200  feet  off  Bavonne  shore  

200  feet  off  Bayonne  shore  

40  38  51 
40  38  51 
40  38  55 
40  38  55 

74  06  08 
74  06  08 
74  06  07 
74  06  07 

15 
30 
1 
15 

Ebb 
Ebb 
Ebb 
Ebb 

20.6 
20.0 
21.1 
20.6 

20 
17 
20 
20 

3.30 
3.59 
3.21 
3.41 

60 
63 
59 
62 

876 
877 
878 
879 

3.50 
4.50 
4.53 
4.55 

200  feet  off  Bayonne  shore 

200  feet  off  Sailors  Snug  Harbor  

200  feet  off  Sailors  Snug  Harbor  

200  feet  off  Sailors  Snug  Harbor  

40  38  55 
40  38  46 
40  38  46 
40  38  46 

74  06  07 
74  06  09 
74  06  09 
74  06  09 

24 
1 
15 
24 

Ebb 
Ebb 
Ebb 
Ebb 

20.0 
21.7 
20.6 
20.6 

18 
21 
20 
18 

3.91 
3.50 
3.60 
4.00 

70 
68 
65 
71 

880 
881 
882 
883 

5.05 
5.08 
5.11 
5.15 

Mid-channel  

Mid-channel  

200  feet  off  Bayonne  shore  

4U  oo  Ol 

40  38  51 
40  38  51 
40  38  55 

7  4    AC  AO 

11  DO  US 

74  06  08 
74  06  08 
74  06  07 

1 

15 
30 
1 

Ebb 
Ebb 
Ebb 
Ebb 

21.1 
21.1 
20.8 
21.7 

24 
24 
22 
27 

3.29 
3.80 
3.54 
4.08 

57 
69 
64 
72 

884 
885 
886 
887 

5  20 
5^25 
6.15 
6.20 

200  feet  off  Bayonne  shore  

200  feet  off  Bayonne  shore  

200  feet  off  Sailors  Snug  Harbor  

200  feet  off  Sailors  Snug  Harbor  

40  38  55 
40  38  55 
40  38  46 
40  38  46 

74  06  07 
74  06  07 
74  06  09 
74  06  09 

15 
24 
1 
15 

Ebb 
Ebb 
Ebb 
Ebb 

21  1 
21.1 
21.9 
21.7 

25 
25 
27 
26 

3  31 

4.24 
3.20 
3.20 

59 
77 
58 
58 

888 
889 
890 
891 

6.25 
6.28 
6.30 
6.35 

200  feet  off  Sailors  Snug  Harbor  

Mid-channel  

Mid-channel  

Mid-channel  

40  38  46 
40  38  51 
40  38  51 
40  38  51 

74  06  09 
74  06  08 
74  06  08 
74  06  08 

24 
1 
15 

30 

Ebb 
Ebb 
Ebb 
Ebb 

21.7 
22.2 
21.7 
21.7 

26 
31 
31 
30 

4.10 
3.66 
3.40 
3.79 

74 
67 
61 
68 

892 
893 
894 

6.40 
6.45 
6.50 

200  feet  off  Bayonne  shore  

200  feet  off  Bayonne  shore  

200  feet  off  Bayonne  shore  

40  38  55 
40  38  55 
40  38  55 

74  06  07 
74  06  07 
74  06  07 

1 

15 
24 

Ebb 
Ebb 
Ebb 

21.7 
21.7 
21.7 

30 
30 
30 

3.51 
3.59 
3.89 

63 
65 
70 

22— EAST  RIVER,  CROSS  SECTION,  THROGS  NECK  TO  CRYDERS  POINT  LANDING.    JULY  14,  1913 

High  water  occurred  at  Governors  Island  at  6.20  P.  M.    Low  water  at  11.50  A.  M.    The  wind  was  west,  with  a  velocity  of 
3  to  40  miles  per  hour. 

895 
896 
897 
898 

A.  M. 
7.25 
7.30 
7.35 
7.40 

300  feet  off  landing,  west  of  light  

300  feet  off  landing,  west  of  light  

300  feet  off  landing,  west  of  light  

M  way  across  

40  48  27 
40  48  27 
40  48  27 
40  48  20 

73  48  16 
73  48  16 
73  48  16 
73  48  18 

1 
18 
42 

1 

Ebb 
Ebb 
Ebb 
Ebb 

18.9 
18.3 
18.3 
18.3 

22 
18 
18 
18 

3.80 
4.00 
4.40 
4.09 

66 
70 
77 
72 

899 
900 
901 
902 

7.45 
7.50 
7.52 
7.56 

]/2  way  across  

40  48  20 
40  48  20 
40  48  09 
40  48  09 

73  48  18 
73  48  18 
73  48  21 
73  48  21 

18 
48 
1 
24 

Ebb 
Ebb 
Ebb 
Ebb 

18.3 
18.3 
18.9 
18.9 

18 
18 
18 
18 

4.61 
5.30 
4.90 
4.75 

81 
93 
86 
84 

903 
904 
905 

7.59 
8.02 
8.05 

Vi  way  across  

%  way  across  

40  48  09 
40  47  58 
40  47  58 

73  48  21 
73  48  24 
73  48  24 

48 
1 
24 

Ebb 
Ebb 
Ebb 

18.3 
18.9 
18.9 

18 
18 
18 

4.38 
4.36 
4.56 

77 
77 

80 

688  DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

TABLE  CXXV— Continued 


22— EAST  RIVER,  CROSS  SECTION,  THROGS  NECK  TO  CRYDERS  POINT  LANDING.    JULY  14,  1913— Continued 


Sample 
No. 

Hour 
A.M. 

Location  of  Samples 

Feet 
below 
surface 

Tidal 
current 

Temp, 
water 
Deg.  C. 

Per 

cent, 
land 
water 

C.  C. 
per 
litre 

gen 

Per 

cent, 
satura- 
tion 

Approximate 

Latitude 

Longitude 

906 
907 
908 
909 

8.12 
8.15 
8.20 
8.25 

Y  way  across  

300  feet  off  landing,  Cryders  Point. . . . 

300  feet  off  landing,  Cryders  Point  

300  feet  off  landing,  Cryders  Point  

o      r  it 

40  47  58 
40  47  50 
40  47  50 
40  47  50 

73  48  24 
73  48  28 
73  48  28 
73  48  28 

48 
1 
24 
42 

Ebb 
Ebb 
Ebb 
Ebb 

18.3 
18.3 
18.3 
18.3 

19 
19 
21 
21 

5.21 
4.76 
4.26 
4.69 

91 

84 
75 
81 

910 
911 
912 
913 

9.45 
9.50 
9.55 
10.00 

300  feet  off  landing,  west  of  light  

300  feet  off  landing,  west  of  light  

300  feet  off  landing,  west  of  light  

Yv  way  across  

40  48  27 
40  48  27 
40  48  27 
40  48  20 

73  48  16 
73  48  16 
73  48  16 
73  48  18 

1 

18 
42 
1 

Ebb 
Ebb 
Ebb 
Ebb 

18.9 
18.3 
18.0 
18.6 

18 
18 
18 
18 

4.70 
4.90 
4.70 
4.80 

83 
86 
82 
84 

914 
915 
916 
917 

10.05 
10.08 
10.10 
10.15 

Y  way  across  

Y  way  across  

Yi  way  across  

Yi  way  across  

40  48  20 
40  48  20 
40  48  09 
40  48  09 

73  48  18 
73  48  18 
73  48  21 
73  48  21 

18 
48 
1 
18 

Ebb 
Ebb 
Ebb 
Ebb 

18.3 
18.3 
18.3 
18.3 

18 
18 
18 
18 

5.61 
5.00 
4.45 
4.97 

98 
88 
78 
87 

918 
919 
920 
921 

10.18 
10.20 
10.25 
10.30 

Yi  way  across  

Y  way  across  

Y  way  across  

40  48  09 
40  47  58 
40  47  58 
40  47  58 

73  48  21 
73  48  24 
73  48  24 
73  48  24 

48 
1 
18 
48 

Ebb 
Ebb 
Ebb 
Ebb 

18.0 
18.9 
18.3 
18.3 

18 
18 
18 
18 

5.69 
4.55 
5.00 
5.15 

98 
80 
87 
90 

922 
923 
924 

925 

10.35 
10.40 
10.45 
P.  M. 
12.25 

300  feet  off  landing,  Cryders  Point  

300  feet  off  landing,  Cryders  Point  

300  feet  off  landing,  Cryders  Point  

300  feet  off  landing,  west  of  light  

40  47  50 
40  47  50 
40  47  50 

40  48  27 

73  48  28 
73  48  28 
73  48  28 

73  48  16 

1 

18 
42 

1 

Ebb 
Ebb 
Ebb 

Ebb 

18.9 
18.3 
18.0 

20.0 

18 
18 
18 

21 

3.51 
4.65 
4.48 

4.90 

61 
81 
78 

88 

926 
927 
928 
929 

12.30 
12.33 
12.35 
12.40 

300  feet  off  landing,  west  of  light  

300  feet  off  landing,  west  of  light  

Y  way  across  

40  48  27 
40  48  27 
40  48  20 
40  48  20 

73  48  16 
73  48  16 
73  48  18 
73  48  18 

18 
42 
1 
18 

Ebb 
Ebb 
Slack 
Slack 

19.4 
18.9 
19.4 
18.9 

21 
20 
21 
20 

4.90 
4.60 
4.79 
4.50 

87 
81 
85 
79 

930 
931 
932 
933 

12.45 
12.50 
12.55 
1.00 

Yl  way  across  

Yi  way  across  

Yi.  way  across  

Yi  way  across  

40  48  20 
40  48  09 
40  48  09 
40  48  09 

73  48  18 
73  48  21 
73  48  21 
73  48  21 

48 
1 
18 
48 

Slack 
Slack 
Slack 
Slack 

18.9 
20.1 
18.9 
18.3 

20 
20 
20 
20 

5.00 
4.05 
4.97 
4.84 

88 
71 

88 
85 

934 
935 
936 
937 

1.05 
1.10 
1.15 
1.17 

Y  way  across  

Y  way  across  

Yi  way  across  

300  feet  off  landing,  Cryders  Point. . . . 

40  47  58 
40  47  58 
40  47  58 
40  47  50 

73  48  24 
73  48  24 
73  48  24 
73  48  28 

1 

18 
48 
1 

Slack 
Slack 
Slack 
Slack 

18.9 
18.9 
18.3 
18.9 

22 
20 
20 
17 

4.36 
4.90 
5.55 
3.92 

76 
87 
96 
66 

938 
939 
940 
941 

1.22 
1.27 
2.35 
2.40 

300  feet  off  landing,  Cryders  Point. . . . 
300  feet  off  landing,  Cryders  Point. . . . 

300  feet  off  landing,  west  of  light  

300  feet  off  landing,  west  of  light  

10  47  50 
40  47  50 
40  48  27 
40  48  27 

73  48  28 
73  48  28 
73  48  16 
73  48  16 

18 
42 
1 
18 

Slack 
Slack 
Flood 
Flood 

18.3 
18.3 
18.9 
18.6 

16 
16 
18 
18 

4.40 
4.48 
5.00 
4.70 

78 
79 
88 
82 

942 
943 
944 
945 

2.44 
2.48 
2.51 
2.55 

Y  way  across  

Y  way  across  

40  48  27 
40  48  20 
40  48  20 
40  48  20 

73  48  Ifi 

73  48  18 
73  48  18 
73  48  18 

42 
1 
18 
48 

Flood 
Flood 
Flood 
Flood 

18.6 
19.4 
19.1 
19.1 

18 
21 
21 
18 

4.30 
4.78 
4.20 
5.20 

75 
84 
74 
92 

947 

948 
949 

3.02 
3.07 
3.15 

Yi  way  across  

Yi  way  across  

Yi  way  across  

Y  way  across  

40  48  09 
40  48  09 
40  48  09 
40  47  58 

73  48  21 
73  48  21 
73  48  21 
73  48  24 

I 

18 
48 
1 

L  LUUU 

Flood 
Flood 
Flood 

18  Q 

18.3 
18.3 
19.4 

20 
20 
21 

4  44 

4.68 
4.46 
4.75 

82 
78 
84 

950 
951 
952 
953 

3.20 
3.25 
3.30 
3.35 

Y  way  across  

300  feet  off  landing,  Cryders  Point  

300  feet  off  landing,  Cryders  Point  

40  47  58 
40  47  58 
40  47  50 
40  47  50 

73  48  24 
73  48  24 
73  48  28 
73  48  28 

18 
48 
1 
18 

Flood 
Flood 
Flood 
Flood 

18.9 
18.9 
20.0 
19.4 

20 
18 
19 
19 

4.29 
4.96 
3.48 
5.00 

76 
87 
60 
89 

954 
955 
956 

3.40 
4.45 
4.47 

300  feet  off  landing,  Cryders  Point  

300  feet  off  landing,  west  of  light  

300  feet  off  landing,  west  of  light  

40  47  50 
40  48  27 
40  48  27 

73  48  28 
73  48  16 
73  48  16 

42 
1 
18 

Flood 
Flood 
Flood 

19.1 
20.0 
19.7 

17 
19 
19 

4.51 
4.50 
4.70 

80 
81 
84 

DISSOLVED  OXYGEN  IN  THE  WATER 


689 


TABLE  CXXV— Continued 


22—  EAST  RIVER,  CROSS  SECTION,  THROGS  NECK  TO  CRYDERS  POINT  LANDING.    JULY  14,  1913— Continued 


Sample 
No. 

Hour 
P.  M. 

Location  of  Samples 

Feet 
below 
surface 

Tidal 
current 

Temp, 
water 
JJeg.  O. 

Per 

cent, 
land 
water 

Ox 

C.  C. 
per 
litre 

ygen 

Per 
cent, 
satura- 
tion 

Approximate 

Latitude 

Longitude 

957 
958 
959 
960 

4.55 
4.58 
4.59 
5.01 

]4\  way  across  

l/i  way  across  

way  across  

o      /  9 

40  48  27 
40  48  20 
40  48  20 
40  48  20 

O         /  V 

73  48  16 
73  48  18 
73  48  18 
73  48  18 

42 
1 

18 
48 

Flood 
Flood 
Flood 
Flood 

19.4 
19.7 
19.4 
18.9 

19 
21 
21 
19 

4.60 
4.00 
3.90 
4.40 

82 
71 
70 
77 

961 
962 
963 
964 

5.05 
5.10 
5.15 
5.18 

Y<i  way  across  

\i  way  across  

%  way  across  

40  48  09 
40  48  09 
40  48  09 
40  47  58 

73  48  21 
73  48  21 
73  48  21 
73  48  24 

1 

18 
48 
1 

Flood 
Flood 
Flood 
Flood 

19.4 
18.9 
18.9 
18.9 

21 
19 
19 
21 

3.79 
4.47 
4.46 
4.26 

67 
79 
78 
75 

965 
966 
967 
968 

5.20 
5.22 
5.25 
5.30 

%  way  across  

300  feet  off  landing,  Cryders  Point .... 
300  feet  off  landing,  Cryders  Point .... 

40  47  58 
40  47  58 
40  47  50 
40  47  50 

73  48  24 
73  48  24 
73  48  28 
73  48  28 

18 
48 
1 
18 

Flood 
Flood 
Flood 
Flood 

18.9 
18.6 
18.9 
18.9 

21 
18 
21 
21 

4.87 
4.96 
3.76 
4.34 

85 
87 
66 
76 

969 
970 
971 
972 

5.35 
6.10 
6.13 
6.18 

300  feet  off  landing,  Cryders  Point .... 

300  feet  off  landing,  west  of  light  

300  feet  off  landing,  west  of  light  

300  feet  off  landing,  west  of  light  

40  47  50 
40  48  27 
40  48  27 
40  48  27 

73  48  28 
73  48  16 
73  48  16 
73  48  16 

42 
1 
18 

42 

Flood 
Flood 
Flood 
Flood 

18.3 
19.4 
18.9 
18.3 

18 
21 
21 
22 

4.00 
4.20 
4.00 
3.90 

70 
74 
70 

68 

973 
974 
975 
976 

6.20 
6  22 
6^25 
6.26 

\i  way  across  

]/i  way  across  

l/i  way  across  

way  across  

40  48  20 
40  48  20 
40  48  20 
40  48  09 

73  48  18 
73  48  18 
73  48  18 
73  48  21 

1 

18 
48 
1 

Flood 
Flood 
Flood 
Slack 

19.4 
18  9 
18'9 
18.9 

21 
21 
21 
21 

4.38 
3  90 
4^11 
3.63 

75 

67 
72 
64 

977 
978 
979 
980 

6.28 
6.30 
6.35 
6.40 

H  way  across  

%  way  across  

%  way  across  

3/i  way  across  

40  48  09 
40  48  09 
40  47  58 
40  47  58 

73  48  21 
73  48  21 
73  48  24 
73  48  24 

18 
48 
1 
18 

Slack 
Slack 
Slack 
Slack 

18.9 
18.3 
18.9 
18.9 

21 
20 
21 
21 

4.16 
4.27 
4.56 
4.80 

73 
74 
80 
85 

981 
982 
983 
984 

6.45 
6.47 
6.50 
6.55 

%  way  across  

300  feet  off  landing,  Cryders  Point .... 

300  feet  off  landing,  Cryders  Point  

300  feet  off  landing,  Cryders  Point. . . . 

40  47  58 
40  47  50 
40  47  50 
40  47  50 

73  48  24 
73  48  28 
73  48  28 
73  48  28 

48 
1 
18 
42 

Slack 
Slack 
Slack 
Slack 

18.9 
18.9 
18.9 
18.9 

20 
21 
21 
20 

4.86 
3.30 
4.64 
4.40 

88 
60 
82 
77 

23— HARLEM  RIVER,  WILLIS  AVENUE  BRIDGE  TO  SPUYTEN  DUYVIL,  JULY  16,  1913 
High  water  occurred  at  Governors  Island  at  6.20  A.  M.    Low  water  at  12.45  P.  M.    There  was  no  wind. 

985 
986 
987 
988 

A.  M. 
10.40 
10.45 
10.55 
11.00 

Willis  Ave.  Bridge,  Manhattan  shore. . 
Willis  Ave.  Bridge,  Manhattan  shore. . 
Willis  Ave.  Bridge,  Manhattan  shore. . 
Willis  Ave.  Bridge,  Bronx  shore  

40  48  12 
40  48  12 
40  48  12 
40  48  12 

73  55  47 
73  55  47 
73  55  47 
73  55  47 

1 
12 
20 

1 

Ebb 
Ebb 
Ebb 
Ebb 

21.1 
21.7 
21.4 
21.7 

28 
25 
25 
23 

1.30 
1.40 
1.40 
1.03 

23 
25 
25 
19 

989 
990 
991 
992 

11.03 
11.08 
11.20 
11.25 

Willis  Ave.  Bridge,  Bronx  shore  

Willis  Ave.  Bridge,  Bronx  shore  

3d  Avenue  Bridge,  midstream  

3d  Avenue  Bridge,  midstream  

40  48  12 
40  48  12 
40  48  25 
40  48  25 

73  55  47 
73  55  47 
73  55  58 
73  55  58 

12 
20 
1 
12 

Ebb 
Ebb 
Ebb 
Ebb 

21.1 
21.1 
21.1 
20.6 

23 
23 
28 
28 

1.17 
2.24 
1.93 
1.89 

21 
41 

35 
33 

993 

994 
995 
996 

11.28 
P.  M. 

12.35 
12.38 
12.40 

3d  Avenue  Bridge,  midstream  

207th  Street  Bridge,  midstream  

207th  Street  Bridge,  midstream  

207th  Street  Bridge,  midstream  

40  48  25 

40  51  46 
40  51  46 
40  51  46 

73  55  58 

73  54  54 
73  54  54 
73  54  54 

20 

1 

12 
18 

Ebb 

Ebb 
Ebb 
Ebb 

20.6 

21.7 
21.7 
21.7 

28 

33 
33 
33 

1.04 

1.20 
1.20 
1.20 

18 

21 
21 
21 

997 
998 
999 
1000 

12.54 
12.57 
1.00 
1.05 

Spuyten  Duyvil,  50  feet  off  north  shore 
Spuyten  Duyvil,  50  feet  off  north  shore 
Spuyten  Duyvil,  50  feet  off  north  shore 
Spuyten  Duyvil,  50  feet  off  north  shore 

40  52  42 
40  52  42 
40  52  42 
40  52  41 

73  55  29 
73  55  29 
73  55  29 
73  55  29 

1 

12 
18 
1 

Ebb 
Ebb 
Ebb 
Ebb 

22.6 
22.2 
22.2 
22.2 

36 
36 
39 
36 

0.75 
0.27 
1.21 
0.84 

14 
5 
21 
15 

1001 
1002 

1.08 
1.12 

Spuyten  Duyvil,  50  feet  off  south  shore 
Spuyten  Duyvil,  50  feet  off  south  shore 

40  52  41 
40  52  41 

73  55  29 
73  55  29 

12 
18 

Ebb 
Ebb 

22.2 
21.9 

39 
39 

1.05 
0.91 

19 
17 

690 


DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


TABLE  CXXV— Continued 

24— HUDSON  RIVER,  CROSS-SECTION,  MT.  ST.  VINCENT.    JULY  16,  1913 


High  water  occurred  at  Governors  Island  at  7.15  A.  M.  Low  water  at  1.35  P.  M.  The  wind  was  north,  with  a  velocity  of 
5  to  40  miles  per  hour. 


Sample 
No. 

Hour 
A.  M. 

Location  of  Samples 

Feet 
below 
surface 

Tidal 
current 

Temp, 
water 
Deg.  C. 

Per 
cent, 
land 
water 

Or 

C.  C. 
per 
litre 

Per 
cent, 
satura- 
tion 

A  nnrAVi T"r~i nlo 
/ippi  UAlIIlillt: 

T.ofif"iiri£» 

T  r\r\  rut"  i  i  ri  £» 
JuUllglLULlC 

1003 
1004 
1005 
1006 

6.50 
6.55 
7.00 
7.10 

300  feet  off  dock  at  Mt.  St.  Vincent. . . 
300  feet  off  dock  at  Mt.  St.  Vincent.. . 

QHO  f00t  nff  flnnlr  at  TVTt    St  Vinnont 

l/i  way  across  

O        /  tt 

40  54  50 

40  54  50 

An  c.a  c.n 
±u  o^  o\j 

40  54  50 

O        /  ft 

73  54  56 
73  54  56 

79   CA  5fi 

#  o  o*±  OO 
73  54  59 

1 

18 
48 
1 

Flood 
Flood 
Flood 
Flood 

22.5 
22.2 
22.2 
22.2 

64 
64 
61 
67 

4.30 
4.80 
3.30 
3.99 

73 
82 
57 
67 

1007 
1008 
1009 
1010 

7.14 
7.18 
7.22 
7.25 

\i  way  across  

H  way  across  

40  54  50 
40  54  50 
An  54  50 

rtU    O^  OVJ 

40  54  50 

73  54  59 
73  54  59 

7Q  55  15 
IO  oo  xo 

73  55  15 

18 
48 
1 
18 

Flood 
Flood 
Flood 
Flood 

22.2 
22.2 
22.2 
22.2 

63 
59 
67 
64 

4.31 
4.65 
3.57 
4.26 

73 
80 
60 
72 

1011 
1012 
1013 
1014 

7.30 
7.33 
7.36 
7.40 

Yi  way  across  

%  way  across  

40  54  50 
40  54  50 

40  54  50 
o^  o\j 

40  54  50 

73  55  15 
73  55  30 

7Q  55  Qfi 
1  o  oo  o\j 

73  55  30 

48 
1 
18 
42 

Flood 
Flood 
Flood 
Flood 

22.2 
22.5 
22.2 
22.2 

56 
67 
63 
55 

4.95 
3.98 
4.65 
5.22 

87 
68 
79 
90 

1015 
1016 
1017 
1018 

7.45 
7.50 
8.00 
9.20 

300  feet  off  New  Jersey  shore  

300  feet  off  New  Jersey  shore  

300  feet  off  Mt.  St.  Vincent  

40  54  50 
40  54  50 

4.0  "14  50 

O^  uU 

40  54  50 

73  55  40 
73  55  40 

7Q  55  An 
1  o  oo  rtU 

73  54  46 

1 

18 
36 
1 

Ebb 
Ebb 
Ebb 
Ebb 

22.5 
22.2 
22.2 
22.5 

64 
64 
64 
61 

4.99 
4.81 
4.41 
3.90 

85 
82 
75 
65 

1019 
1020 
1021 
1022 

9.23 
9.26 
9.30 
9.34 

300  feet  off  Mt.  St.  Vincent  

300  feet  off  Mt.  St.  Vincent  

%  way  across  

40  54  50 
40  54  50 
40  54  50 

40  54  50 
<±\J  O^  OO 

73  54  46 
73  54  46 
73  54  59 

70    C.A  5Q 
/ u   Ot  Ov 

18 
48 
1 
18 

Ebb 
Ebb 
Ebb 
Ebb 

22.5 
22.5 
22.8 
22.5 

61 
54 
62 
61 

4.20 
3.10 
4.09 
4.11 

70 
54 
70 
71 

1023 
1024 
1025 
1026 

9.36 
9.44 
9.48 
9.52 

14  way  across  

Yi  way  across  

40  54  50 
40  54  50 
40  54  50 

40  54  50 

rtO  OU 

73  54  59 
73  55  15 
73  55  15 

70   cc   1 c 
1 0  00  10 

48 
1 

18 
48 

Ebb 
Ebb 
Ebb 
Ebb 

22.5 
22.8 
22.5 
22.2 

53 
62 
62 
55 

4.15 
3.86 
3.76 
4.17 

73 
67 
65 
73 

1027 
1028 
1029 
1030 

9.55 
10.00 
10.05 
10.10 

%  way  across  

%  way  across  

40  54  50 
40  54  50 
40  54  50 

ACW   ZA.  Kf\ 
1U  OU 

73  55  30 
73  55  30 
73  55  30 
±(\ 

1 

18 
48 
1 

Ebb 
Ebb 
Ebb 
Ebb 

22.5 
22.5 
22.5 
23.1 

63 
54 
53 
62 

3.48 
3.50 
4.79 
4.78 

60 
61 
84 
83 

1031 
1032 
1033 
1034 

10.13 
10.17 
11.45 
11.50 

300  feet  off  New  Jersey  shore  

300  feet  off  New  Jersey  shore  

300  feet  off  dock  at  Mt.  St.  Vincent.. . 
300  feet  off  dock  at  Mt.  St.  Vincent.. . 

40  54  50 
40  54  50 
40  54  50 
40  54  50 

73  55  40 
73  55  40 
73  54  46 
73  54  46 

18 
36 
1 
18 

Ebb 
Ebb 
Ebb 
Ebb 

22.8 
22.8 
23.9 
23.3 

60 
58 
59 
59 

4.01 
4.10 
4.98 
4.60 

69 
71 
88 
81 

1035 
1036 
1037 

1038 

11.52 
11.57 
12.00 
P.  M. 
12.03 

300  feet  off  dock  at  Mt.  St.  Vincent. . . 
y±  way  across  

40  54  50 
40  54  50 
40  54  50 

40  54  50 

73  54  46 
73  54  59 
73  54  59 

73  54  59 

31 
1 
18 

42 

Ebb 
Ebb 
Ebb 

Ebb 

22.8 
23.0 
22.8 

22.5 

56 
59 
60 

54 

3.00 
3.98 
4.20 

3.94 

53 
70 
73 

69 

1039 
1040 
1041 
1042 

12.08 
12.13 
12.16 
12.18 

Yi  way  across  

Y<i  way  across  

%  way  across  

40  54  50 
40  54  50 
40  54  50 
40  54  50 

73  55  15 
73  55  15 
73  55  15 
73  55  30 

1 

18 
42 
1 

Ebb 
Ebb 
Ebb 
Ebb 

22.8 
22.8 
22.8 
23.6 

62 
56 
54 
59 

3.96 
4.16 
4.76 
4.12 

70 
73 
86 
73 

1043 
1044 
1045 
1046 

12.21 
12.25 
12.30 
12.35 

%  way  across  

300  feet  off  New  Jersey  shore  

300  feet  off  New  Jersey  shore  

40  54  50 
40  54  50 
40  54  50 
40  54  50 

73  55  30 
73  55  30 
73  55  40 
73  55  40 

18 
42 
1 
12 

Ebb 
Ebb 
Ebb 
Ebb 

23.0 
23.0 
23.9 
23.3 

56 
56 
65 
64 

4.09 
5.12 
4.90 
4.70 

72 
90 
86 
81 

1047 
1048 
1049 
1050 
1051 

12.40 
1.55 
1.59 
2.01 
2.05 

300  feet  off  New  Jersey  shore  

300  feet  off  dock  at  Mt.  St.  Vincent.. . 
300  feet  off  dock  at  Mt.  St.  Vincent. . 
300  feet  off  dock  at  Mt.  St.  Vincent.. . 

40  54  50 
40  54  50 
40  54  50 
40  54  50 
40  54  50 

73  55  40 
73  54  46 
73  54  46 
73  54  46 
73  54  59 

30 
1 

12 
36 
1 

Ebb 
Flood 
Flood 
Flood 
Flood 

23.0 
23.9 
23.3 
23.3 
23.3 

59 
63 
62 
58 
66 

4.05 
4.37 
4.40 
4.30 
5.20 

71 
77 
78 
76 
90 

DISSOLVED  OXYGEN  IN  THE  WATER 


691 


TABLE  CXXV— Continued 


24 — HUDSON  RIVER,  CROSS-SECTION,  MT.  ST.  VINCENT.    JULY  16,  1913— Continued 


Sample 
No. 

Hour 
P.  M. 

Location  of  Samples 

Feet 
below 

ci  ir-fo  no 

bill  1  a<_  t. 

Tidal 
current 

Temp, 
water 

Per 

cent, 
land 

water 

Oxj 

C.  C. 
per 
litre 

'gen 

Per 
cent, 
satura- 
tion 

Approximate 

Latitude 

Longitude 

1052 
1053 
1054 
1055 

2.10 
2.12 
2.17 
2.20 

way  across  

14  way  across  

x/i  way  across  

34  way  across  

Oil 

40  54  50 
40  54  50 
40  54  50 
40  54  50 

Ota 

73  54  59 
73  54  59 
73  55  15 
73  55  15 

18 
42 
1 
18 

Flood 
Flood 
Flood 
Flood 

23.1 
22.8 
23.9 
23.3 

60 
58 
69 
62 

4.41 
4.46 
4.68 
4.66 

77 
78 
81 
81 

1056 
1057 
1058 
1059 

2.25 
2.30 
2.34 
2.38 

y%  way  across  

%  way  across  

Y±  way  across  

%  way  across  

40  54  50 
40  54  50 
49  54  50 
40  54  50 

73  55  15 
73  55  30 
73  55  30 
73  55  30 

42 
1 
12 
24 

Flood 
Flood 
Flood 
Flood 

23.3 
24.1 
23.3 
23.1 

62 
69 
68 
63 

5.43 
4.76 
5.62 
5.76 

94 
83 
95 
98 

1060 
1061 
1062 
1063 

2.40 
2.45 
2.50 
4.50 

300  feet  off  New  Jersey  shore  

300  feet  off  New  Jersey  shore  

300  feet  off  New  Jersey  shore  

300  feet  off  dock  at  Mt.  St.  Vincent.. . 

40  54  50 
40  54  50 
40  54  50 
40  54  50 

73  55  40 
73  55  40 
73  55  40 
73  54  46 

1 

12 
24 
1 

Flood 
Flood 
Flood 
Flood 

23.9 
23.0 
23.3 
24.5 

69 
70 
70 
68 

5.79 
5.90 
6.06 
6.07 

102 
102 
103 
108 

1064 
1065 
1066 
1067 

4.53 
4.56 
4.58 
5.01 

300  feet  off  dock  at  Mt.  St.  Vincent.. . 
300  feet  off  dock  at  Mt.  St.  Vincent.. . 

%  way  across  

%  way  across  

40  54  50 
40  54  50 
40  54  50 
40  54  50 

73  54  46 
73  54  46 
73  54  59 
73  54  59 

18 
30 
1 
18 

Flood 
Flood 
Flood 
Flood 

23.6 
23.9 
23.3 
23.1 

63 
55 
69 
64 

4.60 
4.30 
5.80 
5.32 

80 
76 
101 
93 

1068 
1069 
1070 
1071 

5.05 
5.08 
5.11 
5.15 

\i  way  across  

Vi  way  across  

Yi  way  across  

x/2  way  across  

40  54  50 
40  54  50 
40  54  50 
40  54  50 

73  54  59 
73  55  15 
73  55  15 
73  55  15 

36 
1 
18 

36 

Flood 
Flood 
Flood 
Flood 

23.9 
23.3 
23.3 
23.3 

60 
67 
66 
55 

4.67 
5.78 
4.26 
5.22 

82 
101 
74 
93 

1072 
1073 
1074 
1075 

5.20 
5.22 
5.26 
5.30 

%  way  across  

%  way  across  

%  way  across  

300  feet  off  New  Jersey  shore  

40  54  50 
40  54  50 
40  54  50 
40  54  50 

73  55  30 
73  55  30 
73  55  30 
73  55  40 

1 

12 
24 
1 

Flood 
Flood 
Flood 
Flood 

23.9 
24.1 
23.3 
23.9 

73 
69 
62 
69 

5.95 
6.38 
6.06 
6.40 

103 
112 
106 
112 

1076 
1077 

5.35 
5.40 

300  feet  off  New  Jersey  shore  

300  feet  off  New  Jersey  shore  

40  54  50 
40  54  50 

73  55  40 
73  55  40 

12 
18 

Flood 
Flood 

23.9 
23.3 

71 

78 

6.00 
6.42 

104 
109 

25— HUDSON  RIVER,  YONKERS  TO  PIER  A.    JULY  17,  1913 

High  water  occurred  at  Governors  Island  at  7.50  A.  M.    Low  water  at  2.10  P.  M.    The  wind  was  light,  and  varied  from 
north  to  south. 

1078 
1079 
1080 
1081 

A.M. 
6.55 

6.58 

7.00 

7.20 

Midstream,   opposite   Power  House 
above  Yonkers  

Midstream,   opposite   Power  House 
above  Yonkers  

Midstream,    opposite   Power  House 
above  Yonkers  

Midstream,  opposite  Mt.  St.  Vincent.. 

40  56  55 

40  56  55 

40  56  55 
40  54  50 

73  54  35 

73  54  35 

73  54  35 
73  55  15 

1 

18 

42 
1 

Flood 

Flood 

Flood 
Flood 

22.8 

23.1 

22.8 
22.8 

70 

64 

60 
68 

5.58 
3.90 

4.70 

5.58 

95 
68 

81 

95 

1082 
1083 
1084 
1085 

7.25 
7.35 
7.45 
7.50 

Midstream,  opposite  Mt.  St.  Vincent. . 
Midstream,  opposite  Mt.  St.  Vincent. . 

Midstream,  opposite  Riverdale  

Midstream,  opposite  Riverdale  

40  54  50 
40  54  50 
40  54  10 
40  54  10 

73  55  15 
73  55  15 
73  55  25 
73  55  25 

18 
42 
1 
12 

Flood 
Flood 
Flood 
Flood 

23.1 

22.8 
22.8 
22.8 

62 
56 
64 
52 

4.50 
4.40 
5.58 
3.80 

79 
77 
95 
67 

1086 
1087 
1088 
1089 

7.55 
8.15 
8.20 
8.25 

Midstream,  opposite  Riverdale  

Midstream,  opposite  Spuyten  Duyvil. . 
Midstream,  opposite  Spuyten  Duyvil. . 
Midstream,  opposite  Spuyten  Duyvil. . 

40  54  10 
40  52  50 
40  52  50 
40  52  50 

73  55  25 
73  56  04 
73  56  04 
73  56  04 

24 
1 
12 
24 

Flood 
Ebb 
Ebb 
Ebb 

22.8 
22.8 
22.8 
22.2 

52 
58 
54 
57 

2.90 
4.18 
3.90 
2.90 

51 
71 

68 
50 

1090 
1091 
1092 
1093 

8.45 
8.50 
8.55 
9.20 

Midstream,  opposite  Inwood  

Midstream,  opposite  Inwood  

Midstream,  opposite  Inwood  

Mid-channel,  opposite  Ft.  Washington 
Point  

40  52  20 
40  52  20 
40  52  20 

40  51  04 

73  56  24 
73  56  24 
73  56  24 

73  57  13 

1 

12 

30 

1 

Ebb 
Ebb 
Ebb 

Ebb 

23.1 
22.5 
22.2 

22.2 

56 
51 
49 

49 

4.48 
2.80 
2.90 

4.08 

79 
49 
51 

72 

692 


DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


TABLE  CXXV— Continued 


25— HUDSON  RIVER,  YONKERS  TO  PIER  A.    JULY  17,  1913— Continued 


Sample 
No. 

Hour 
A.  M. 

Location  of  Samples 

Feet 
below 
surface 

Tidal 
current 

Temp, 
water 
Deg.  C. 

Per 
cent, 
land 
water 

Ox 

C.  C. 
per 
litre 

Per 
cent, 
satura- 
tion 

Approximate 

Latitude 

Longitude 

1094 

1095 

1096 
1097 

9.30 

9.35 

9.55 
10.06 

Mid-channel,  opposite  Ft.  Washington 
Point  

Mid-channel,  opposite  Ft.  Washington 
Point  

Mid-channel,  opposite  129th  street.. .  . 

Mid-channel,  opposite  129th  street. . .  . 

O         /  If 

40  51  04 

40  51  04 
40  49  16 
40  49  16 

O         t  If 

73  57  13 

73  57  13 
73  58  10 
73  58  10 

18 

48 
1 
18 

Ebb 

Ebb 
Ebb 
Ebb 

22.1 

21.7 

22.8 
22.2 

47 

44 
42 
41 

3.30 

2.00 
3.69 
2.60 

58 

35 
67 
46 

1098 
1099 
1100 
1101 

10.10 
10.30 
10.35 
10.40 

Mid-channel,  opposite  129th  street.. .  . 
Mid-channel,  opposite  W.  110th  street 
Mid-channel,  opposite  W.  110th  street 
Mid-channel,  opposite  W.  110th  street 

40  49  16 
40  48  32 
40  48  32 
40  48  32 

73  58  10 
73  58  40 
73  58  40 
73  58  40 

48 
1 
18 
48 

Ebb 
Ebb 
Ebb 
Ebb 

21.7 
22.2 
22.0 
21.7 

35 
37 
37 
35 

3.50 
3.28 
3.20 
3.30 

63 
59 
57 
59 

1102 

1103 
1104 
1105 

10.55 
11.00 
11.05 
11.25 

Mid-channel,  opposite  W.  72d  street.  . 

Mid-channel,  opposite  W.  72d  street.  . 
Mid-channel,  opposite  W.  42d  street.  . 

40  47  02 
40  47  02 
40  47  02 
40  45  50 

73  69  42 
73  69  42 

73  69  42 

74  00  35 

1 

18 
48 
1 

Ebb 
Ebb 
Ebb 
Ebb 

22.2 
21.7 
21.4 
21.7 

35 
35 
33 
33 

3.59 
3.30 
2.50 
3.09 

65 
59 
45 
55 

1106 
1107 
1108 
1109 

11.28 
11.30 
11.45 
11.50 

Mid-channel,  opposite  W.  42d  street.  . 
Mid-channel,  opposite  W.  42d  street.  . 

Mid-channel,  off  23d  street  

Mid-channel,  off  23d  street  

40  45  50 
40  45  50 
40  45  09 
40  45  09 

74  00  35 
74  00  35 
74  01  00 
74  01  00 

18 
48 
1 
18 

Ebb 
Ebb 
Ebb 
Ebb 

21.7 
21.1 
22.0 
21.7 

33 
30 
33 
33 

2.50 
3.80 
3.59 
3.30 

45 
68 
63 
59 

1110 

1111 
1112 
1113 

11.55 
P.  M. 
12.15 
12.20 
12.25 

Mid-channel,  off  23d  street  

Mid-channel,  off  Canal  street  

Mid-channel,  off  Canal  street  

Mid-channel,  off  Canal  street  

40  45  09 

40  43  38 
40  43  38 
40  43  38 

74  01  00 

74  01  17 
74  01  17 
74  01  17 

30 

1 

18 
42 

Ebb 

Ebb 
Ebb 
Ebb 

21.1 

21.7 
21.1 

20.3 

30 

31 
28 
26 

3.60 

3.99 
3.10 
3.40 

64 

70 
55 
61 

1114 
1115 
1116 

12.40 
12.45 
12.50 

Mid-channel,  off  Pier  A  

Mid-channel,  off  Pier  A  

Mid-channel,  off  Pier  A  

40  42  19 
40  42  19 
40  42  19 

74  01  34 
74  01  34 
74  01  34 

1 

18 
36 

Ebb 
Ebb 
Ebb 

21.9 
21.1 
20.6 

28 
27 
26 

3.68 
3.30 
2.90 

67 
59 
52 

26— EAST  RIVER,  CROSS  SECTION,  PIER  10,  MANHATTAN,  TO  PIER  10,  BROOKLYN,  JULY  18,  1913 

High  water  occurred  at  Governors  Island  at  8.10  A.  M.    Low  water  at  2.50  P.  M.    The  wind  was  light  and  variable. 

1117 
1118 
1119 
1120 

A.  M. 
7.25 
7.28 
7.32 
7.38 

100  feet  off  Pier  10,  Manhattan  

100  feet  off  Pier  10,  Manhattan  

100  feet  off  Pier  10,  Manhattan  

Yi  way  across  

40  42  09 
40  42  09 
40  42  09 
40  42  07 

74  00  22 
74  00  22 
74  00  22 
74  00  17 

1 

15 
30 
1 

Flood 
Flood 
Flood 
Flood 

20.0 
20.3 
20.3 
20.3 

25 
24 
24 
26 

3.39 
2.90 
2.80 
2.56 

60 
52 
50 
46 

1121 
1122 
1123 
1124 

7.41 
7.46 
7.50 
7.55 

Y  way  across  

Y  way  across  

Yz  way  across  

Yi  way  across  

40  42  07 
40  42  07 
40  42  03 
40  42  03 

74  00  17 
74  00  17 
74  00  11 
74  00  11 

15 
40 
1 
15 

Flood 
Flood 
Flood 
Flood 

20.3 
20.0 
20.0 
20.0 

26 
25 
25 
25 

2.99 
2.27 
2.40 
3.05 

53 
40 
42 
54 

1125 
1126 
1127 
1128 

8.00 
8.05 
8.09 
8.11 

Yh  way  across  

%  way  across  

%  way  across  

%  way  across  

40  42  03 
40  42  00 
40  42  00 
40  42  00 

74  00  11 
74  00  05 
74  00  05 
74  00  05 

40 
1 
15 

35 

Flood 
Flood 
Flood 
Flood 

20.0 
20.0 
20.0 
20.0 

23 
27 
27 
27 

3.71 
2.66 
2.92 
4.32 

66 
47 
51 
76 

1129 
1130 
1131 
1132 

8.15 
8.20 
8.25 
9.30 

100  feet  off  Pier  10,  Brooklyn  

100  feet  off  Pier  10,  Brooklyn  

100  feet  off  Pier  10,  Brooklyn  

100  feet  off  Pier  10,  Manhattan  

40  41  57 
40  41  57 
40  41  57 
40  42  09 

74  00  00 
74  00  00 
74  00  00 
74  00  22 

1 

15 
30 
1 

Flood 
Flood 
Flood 
Ebb 

20.0 
20.0 
20.0 
20.0 

25 
23 
23 
23 

3.29 
3.20 
3.08 
2.69 

59 
57 
55 
48 

1133 
1134 
1135 
1136 
1137 

9.35 
9.40 
9.42 
9.46 
9.49 

100  feet  off  Pier  10,  Manhattan  

100  feet  off  Pier  10,  Manhattan  

Y  way  across  

40  42  09 
40  42  09 
40  42  07 
40  42  07 
40  42  07 

74  00  22 
74  00  22 
74  00  17 
74  00  17 
74  00  17 

15 
30 
1 
15 
40 

Ebb 
Ebb 
Ebb 
Ebb 
Ebb 

20.0 
20.0 
20.0 
20.0 
20.0 

23 
23 
23 
21 
21 

3.40 
2.50 
2.87 
3.09 
3.51 

60 
45 
51 
55 
62 

DISSOLVED  OXYGEN  IN  THE  WATER 


G93 


TABLE  CXXV— Continued 


26 — EAST  RIVER,  CROSS  SECTION,  PIER  10,  MANHATTAN,  TO  PEER  10,  BROOKLYN.    JULY  18,  1913— Continued 


Sample 
No. 

Hour 
A.  M. 

Location  of  Samples 

Feet 
below 
surface 

Tidal 
current 

Temp, 
water 
ueg.  u. 

Per 
cent, 
land 
water 

Ox 

C.  C. 
per 
litre 

ygen 

Per 
cent, 
satura- 
tion 

Approximate 

Latitude 

Longitude 

1138 
1139 
1140 
1141 

9.51 
9.54 
9.58 
10.00 

3/i  way  across  

o     /  r 

40  42  03 
40  42  03 
40  42  03 
40  42  00 

OIK 

74  00  11 
74  00  11 
74  00  11 
74  00  05 

1 

15 
40 
1 

Ebb 
Ebb 
Ebb 
Ebb 

20.0 
20.0 
20.0 
20.0 

25 
25 
25 
25 

2.91 
3.45 
3.00 
2.93 

52 
61 
54 
52 

1142 
1143 
1144 
1145 

10.05 
10.10 
10  40 
10.45 

%  way  across  

3/^  wav  ftPrn^Q 

100  feet  off  Pier  10,  Brooklyn  

100  feet  off  Pier  10,  Brooklyn  

40  42  00 
40  42  00 

IV        ^irf  \J\J 

40  41  57 
40  41  57 

74  00  05 
74  00  05 

I          \J\J  \J\J 

74  00  00 
74  00  00 

15 
35 
1 
15 

Ebb 
Ebb 
Ebb 
Ebb 

20.0 
20.0 
20.0 
20.0 

25 
25 
23 
23 

3.60 
4.32 
2.88 
2.92 

64 
76 
51 

52 

1146 
1147 
1148 
1149 

10.50 
11.45 
11  47 
11.50 

100  feet  off  Pier  10,  Brooklyn  

100  fppt  off  Pier  10  Manhattan 

100  feet  off  Pier  10,  Manhattan  

100  feet  off  Pier  10,  Manhattan  

40  41  57 
40  42  09 
40  42  09 
40  42  09 

74  00  00 
74  00  22 
74  00  22 
74  00  22 

30 
1 
15 
30 

Ebb 
Ebb 
Ebb 
Ebb 

20.0 
21.1 
21.1 

20.6 

23 
24 
24 
24 

2.38 
2.60 
2.60 
2.50 

42 
47 
47 
45 

1150 
1151 

1152 
1153 

11.55 
11.58 
P.M. 
12.01 
12.05 

\i,  way  across  

\4  wav  acro'vi 

way  across  

3^  way  across  

40  42  07 
40  42  07 

40  42  07 
40  42  03 

74  00  17 
74  00  17 

74  00  17 
74  00  11 

1 

15 

40 
1 

Ebb 
Ebb 

Ebb 
Ebb 

20.6 
20.6 

20.6 
20.6 

22 
22 

22 
24 

1.96 
2.38 

2.55 
1.99 

35 
43 

46 
35 

1154 
1155 
1156 
1157 

12.10 
12.14 
12.17 
12.20 

\&  wiv  actors 

]/2  way  across  

J^'way  across  

%  way  across  

40  42  03 
40  42  03 
40  42  00 
40  42  00 

74  00  11 
74  00  11 
74  00  05 
74  00  05 

15 
40 
1 
15 

Ebb 
Ebb 
Ebb 
Ebb 

20.6 
20.8 
20.8 
20.8 

24 
24 
28 
24 

2.45 
2.78 
2.26 
2.19 

44 
50 
40 
37 

1158 
1159 
1160 
1161 

12.25 
12.30 
12.33 
12.35 

100  feet  off  Pier  10,  Brooklyn  

100  feet  off  Pier  10,  Brooklyn  

100  feet  off  Pier  10,  Brooklyn  

40  42  00 
40  41  57 
40  41  57 
40  41  57 

74  00  05 
74  00  00 
74  00  00 
74  00  00 

35 
1 
15 
30 

Ebb 
Ebb 
Ebb 
Ebb 

20.6 
20.8 
20.8 
20.8 

24 
24 
24 
24 

3.18 
2.37 
2.11 
1.88 

57 
42 
38 
33 

1162 
1163 
1164 
1165 

1.37 
1.40 
1.45 
1.47 

100  fppt  off  Pier  10  Manhattan 

100  feet  off  Pier  10,  Manhattan  

100  feet  off  Pier  10,  Manhattan  

way  across  

40  42  09 
40  42  09 
40  42  09 
40  42  07 

74  00  22 
74  00  22 
74  00  22 
74  00  17 

1 

15 
30 
1 

Ebb 
Ebb 
Ebb 
Ebb 

21.1 
21.1 
21.1 
21.1 

24 
24 
24 
24 

2.49 
2.20 
1.80 
1.56 

45 
40 
32 
28 

1166 
1167 
1168 
1169 

1.49 
1.55 
2.00 
2.05 

X/^  wav  apiyias 

Yi  way  across  

Yi  way  across  

40  42  07 
40  42  07 
40  42  03 
40  42  03 

74  00  17 
74  00  17 
74  00  11 
74  00  11 

15 
40 
1 
15 

Ebb 
Ebb 
Ebb 
Ebb 

21.1 
21.1 
21.1 
21.1 

24 
24 
24 
24 

1.88 
2.36 
1.48 
1.85 

34 
43 
27 
32 

1170 
1171 
1172 
1173 

2.08 
2.10 

2.15 
2.20 

%  way  across  

4(1  4r>  f)3 
40  42  00 
40  42  00 
40  42  00 

74  00  11 

t  ^   \J\J    X  X 

74  00  05 
74  00  05 
74  00  05 

40 
1 

15 
35 

Ebb 
Ebb 
Ebb 
Ebb 

21.1 
21.1 
21.1 
21.1 

24 
24 
24 
24 

1.12 
1.56 
1.88 
2.80 

20 
28 
34 
50 

1174 
1175 
1176 
1177 

2.25 
2.27 
2.30 
3.40 

l  c\f\  f„nt  „ce  td;„—  t  c\    t~>  11 

100  feet  off  Pier  10,  Brooklyn  

100  feet  off  Pier  10,  Brooklyn  

100  feet  off  Pier  10,  Manhattan  

40  41  57 
40  41  57 
40  41  57 
40  42  09 

t 4  00  00 
74  00  00 
74  00  00 
74  00  22 

1 

15 
30 
1 

Flood 
Flood 
Flood 
Flood 

21.1 
21.1 
21.1 
21.7 

24 
24 
24 
23 

2.17 
2.01 
1.78 
2.69 

39 
36 
32 
49 

1178 
1179 
1180 
1181 

3  43 
3.45 
3.50 
3.54 

100  feet  off  Pier  10,  Manhattan  

100  feet  off  Pier  10,  Manhattan  

34  way  across  

40  42  09 
40  42  09 
40  42  07 
40  42  07 

74  00  22 
74  00  22 
74  00  17 
74  00  17 

15 
30 
1 
15 

Flood 
Flood 
Flood 
Flood 

21  1 
21 .1 
21.1 
20.8 

24 
22 
24 
24 

1.80 
L90 
1.67 
1.48 

33 
35 
30 
26 

1182 
1183 
1184 
1185 

3.56 
4.00 
4.04 
4.08 

Yi  way  across  

Yi  way  across  

Yi  way  across  

40  42  07 
40  42  03 
40  42  03 
40  42  03 

74  00  17 
74  00  11 
74  00  11 
74  00  11 

40 
1 
15 
40 

Flood 
Flood 
Flood 
Flood 

20.8 
21.1 
21.1 
21.1 

24 
26 
26 
26 

2.26 
0.87 
1.36 
2.06 

40 
15 
24 
37 

1186 
1187 
1188 

4.10 
4.12 
4.15 

%  way  across  

%  way  across  

40  42  00 
40  42  00 
40  42  00 

74  00  05 
74  00  05 
74  00  05 

1 

15 
35 

Flood 
Flood 
Flood 

21.1 
21.1 
20.8 

24 
24 
22 

1.94 
2.74 
3.17 

35 
51 
57 

694  DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

TABLE  CXXV— Continued 


26— EAST  RIVER,  CROSS  SECTION,  PIER  10,  MANHATTAN,  TO  PIER  10,  BROOKLYN,    JULY  18,  1913— Continued 


Sample 
No. 

Hour 
P.  M. 

Location  of  Samples 

Feet 
below 
surface 

Tidal 
current 

Temp, 
water 
Deg.  L>. 

Per 
cent, 
land 
water 

Ox; 

c.  c. 

per 
litre 

('gen 

Per 
cent, 
satura- 
tion 

Approximate 

Latitude 

Longitude 

1189 
1190 
1191 
1192 

4.20 
4.25 
4.30 
6.05 

100  fppt  off  Pipr  10  Rrooklvn 

100  feet  off  Pier  10,  Brooklyn  

100  feet  off  Pier  10,  Brooklyn  

100  feet  off  Pier  10,  Manhattan  

O      9  V 

40  41  57 
40  41  57 
40  41  57 
40  42  09 

O      /  9 

74  00  00 
74  00  00 
74  00  00 
74  00  22 

1 

15 
30 
1 

Flood 
Flood 
Flood 
Flood 

21.1 
21.1 

20.8 
22.2 

24 
24 
24 
31 

1.76 
2.11 
1.58 
1.77 

32 
38 
28 
32 

1193 
1194 
1195 
1196 

6.09 
6.12 
6.15 
6.18 

100  feet  off  Pier  10,  Manhattan  

100  feet  off  Pier  10,  Manhattan  

Yt  way  across  

Y  way  across  

40  42  09 
40  42  09 
40  42  07 
40  42  07 

74  00  22 
74  00  22 
74  00  17 
74  00  17 

15 
30 
1 
15 

Flood 
Flood 
Flood 
Flood 

21.4 
20.8 
21.1 
21.1 

23 
24 
26 
26 

1.20 
1.20 
1.36 
1.08 

22 
22 
24 
19 

1197 
1198 
1199 
1200 

6.20 
6.25 
6.28 
6.30 

Y  way  across  

Yi  way  across  

Yi  way  across  

Yi  way  across  

40  42  07 
40  42  03 
40  42  03 
40  42  03 

74  00  17 
74  00  11 
74  00  11 
74  00  11 

40 
1 
15 
40 

Flood 
Flood 
Flood 
Flood 

20.6 
21.1 
21.1 
20.8 

28 
28 
28 
26 

1.58 
0.71 
1.36 
1.26 

28 
13 
24 
22 

1201 
1202 
1203 
1204 

6.34 
6.36 
6.39 
6.40 

%  way  across  

Yt  way  across  

Y  way  across  

100  feet  off  Pier  10,  Brooklyn  

40  42  00 
40  42  00 
40  42  00 
40  41  57 

74  00  05 
74  00  05 
74  00  05 
74  00  00 

1 

15 
35 
1 

Flood 
Flood 
Flood 
Flood 

21.1 
21.1 
21.1 
21.4 

32 
30 
28 
31 

0.92 
1.55 
2.44 
1.75 

16 
28 
44 
31 

1205 
1206 

6.45 
6.50 

100  feet  off  Pier  10,  Brooklyn  

100  feet  off  Pier  10,  Brooklyn  

40  41  57 
40  41  57 

74  00  00 
74  00  00 

15 
30 

Flood 
Flood 

21.1 

20.8 

28 
28 

2.10 
1.59 

38 
28 

27— NARROWS,  CROSS-SECTION,  FORT  LAFAYETTE  TO  FORT  WADSWORTH.    JULY  24,  1913 

Low  water  occurred  at  Governors  Island  at  6.10  A.  M.    High  water  at  1.00  P.  M.    The  wind  was  southeast,  with  a  velocity 
of  5  miles  per  hour. 

1207 
1208 
1209 
1210 

A.M. 
7.30 
7.33 
7.38 
7.40 

200  feet  off  Fort  Lafayette  

200  feet  off  Fort  Lafayette  

200  feet  off  Fort  Lafayette  

Y  way  across  

40  36  29 
40  36  29 
40  36  29 
40  36  27 

74  02  24 
74  02  24 
74  02  24 
74  02  34 

1 

18 
54 
1 

Flood 
Flood 
Flood 
Flood 

21.1 
21.1 
20.6 
21.1 

20 
22 
18 
24 

3.20 
3.40 
4.26 
2.70 

58 
62 
77 
49 

1211 
1212 
1213 
1214 

7.43 
7.45 
7.50 
7.53 

Y  way  across  

Yz  way  across  

Yi  way  across  

40  36  27 
40  36  27 
40  36  25 
40  36  25 

74  02  34 
74  02  34 
74  02  48 
74  02  48 

24 
54 
1 
30 

Flood 
Flood 
Flood 
Flood 

21.1 

20.6 
21.1 
20.6 

20 
20 
24 
20 

2.73 
4.32 
3.01 
4.49 

50 
78 
55 
81 

1215 
1216 
1217 
1218 

7.57 
8.03 
8.06 
8.10 

Yi  way  across  

%  way  across  

%  way  across  

YL  way  across  

40  36  25 
40  36  23 
40  36  23 
40  36  23 

74  02  48 
74  03  02 
74  03  02 
74  03  02 

54 
1 
30 
54 

Flood 
Flood 
Flood 
Flood 

20.6 
21.1 
20.9 
20.6 

16 
24 
20 
16 

3.98 
3.22 
3.03 
4.16 

72 
58 
54 
76 

1219 
1220 
1221 
1222 

8.15 
8.18 
8.25 
9.35 

200  feet  off  Fort  Wadsworth  

200  feet  off  Fort  Wadsworth  

200  feet  off  Fort  Wadsworth  

200  feet  off  Fort  Lafayette  

40  36  21 
40  36  21 
40  36  21 
40  36  29 

74  03  12 
74  03  12 
74  03  12 
74  02  24 

1 

30 
60 
1 

Flood 
Flood 
Flood 
Flood 

21.1 

20.9 
20.6 
22.2 

24 
20 
18 
19 

2.92 
4.30 
3.94 
3.30 

56 
77 
72 
66 

1223 
1224 
1225 
1226 

9.38 
9.40 
9.45 
9.48 

200  feet  off  Fort  Lafayette  

200  feet  off  Fort  Lafayette  

Y  way  across  

40  36  29 
40  36  29 
40  36  27 
40  36  27 

74  02  24 
74  02  24 
74  02  34 
74  02  34 

30 
45 
1 
30 

Flood 
Flood 
Flood 
Flood 

21.1 
20.6 
21.4 
20.8 

18 
16 
21 
20 

3.90 
4.15 
3  38 
3.84 

71 

75 
62 
70 

1227 
1228 
1229 
1230 

9.52 
9.55 
9.58 
10.00 

Y  way  across  

Yi  way  across  

Yi  way  across  

40  36  27 
40  36  25 
40  36  25 
40  36  25 

74  02  34 
74  02  48 
74  02  48 
74  02  48 

60 
1 
30 
60 

Flood 
Flood 
Flood 
Flood 

20.6 
21.1 
20.8 
20.6 

18 
21 
18 
18 

4.24 
3.88 
4.38 
4.29 

76 
70 
80 
76 

1231 
1232 
1233 

10.05 
10.10 
10.12 

%  way  across  

40  36  23 
40  36  23 
40  36  23 

74  03  02 
74  03  02 
74  03  02 

1 

30 
60 

Flood 
Flood 
Flood 

21.1 

20.8 
20.6 

20 
20 
18 

4.38 
3.33 
3.76 

80 
60 
68 

DISSOLVED  OXYGEN  IN  THE  WATER 


695 


TABLE  CXXV— Continued 


27— NARROWS,  CROSS-SECTION,  FORT  LAFAYETTE  TO  FORT  WADSWORTH.    JULY  24   1913— Continued 


Sample 
No. 

Hour 
A.  M. 

Location  of  Samples 

Feet 
below 
surface 

Tidal 
current 

Temp, 
water 
Deg.  C. 

Per 
cent, 
land 
water 

Ox 

C.  C. 
per 
litre 

ygen 

Per 
cent, 
satura- 
tion 

Approximate 

Latitude 

Longitude 

1234 
1235 
1236 
1237 

10.18 
10.20 
10.25 
11.50 

200  feet  off  Fort  Wadsworth  

200  feet  off  Fort  Wadsworth  .  .  . 

200  feet  off  Fort  Wadsworth  

200  feet  off  Fort  Lafayette  

O        /  V 

40  36  21 
40  36  21 
40  36  21 
40  36  29 

O      t  9 

74  03  12 
74  03  12 
74  03  12 
74  02  24 

1 

18 
40 
1 

Flood 
Flood 
Flood 
Ebb 

21.1 
21.1 
20.8 
21.4 

22 
16 
20 
19 

3.43 
4.30 
3.74 
3.20 

63 
79 
68 
59 

1238 
1239 
1240 

1241 

11.53 
11.58 
12.00 
P.  M. 
12.03 

200  feet  off  Fort  Lafayette  

200  feet  off  Fort  Lafayette  

x/i  way  across  

40  36  29 
40  36  29 
40  36  27 

40  36  27 

74  02  24 
74  02  24 
74  02  34 

74  02  34 

30 
54 
1 

30 

Ebb 
Ebb 
Ebb 

Ebb 

20.8 
20.8 
21.1 

21.1 

16 
16 
19 

19 

4.10 
4.35 
4.38 

4.14 

75 
80 
80 

76 

1242 
1243 
1244 
1245 

12.05 
12.08 
12.15 
12.20 

way  across  

Yi  way  across  

Yz  way  across  

40  36  27 
40  36  25 
40  36  25 
40  36  25 

74  02  34 
74  02  48 
74  02  48 
74  02  48 

60 
1 

30 
60 

Ebb 
Ebb 
Ebb 
Ebb 

20.8 
21.7 
21.1 
21.1 

18 
21 
19 
18 

4.64 
4.57 
5.33 
5.19 

85 
84 
98 
95 

1246 
1247 
1248 
1249 

12.25 
12.29 
12.32 
12.35 

%  way  across  

%  way  across  

Y±  way  across  

200  feet  off  Fort  Wadsworth  

40  36  23 
40  36  23 
40  36  23 
40  36  21 

74  03  02 
74  03  02 
74  03  02 
74  03  12 

1 

30 
60 
1 

Ebb 
Ebb 
Ebb 
Ebb 

21.1 
21.1 
21.1 

20.6 

21 
19 
19 

22 

4.19 
4.68 
4.86 
3.94 

77 
86 
89 
71 

1250 
1251 
1252 
1253 

12.40 
12.45 
2.55 
3.00 

200  feet  off  Fort  Wadsworth  

200  feet  off  Fort  Wadsworth  

200  feet  off  Fort  Lafayette  

40  36  21 
40  36  21 

if\  Qft  OO 

w  oo 
40  36  29 

74  03  12 
74  03  12 

7  A  fiO  OA 

74  02  24 

18 
40 
1 
30 

Ebb 
Ebb 
Ebb 
Ebb 

20.6 
20.6 
21.1 
20.8 

20 
20 
24 
18 

4.68 
4.96 
4.40 
4.60 

86 
90 
80 
84 

1254 
1255 
1256 
1257 

3.05 
3.07 
3  12 
3.16 

200  feet  off  Fort  Lafayette  

l/i  way  across  

\i  way  across  

40  36  29 
40  36  27 
40  36  27 
40  36  27 

74  02  24 
74  02  34 
74  02  34 
74  02  34 

54 
1 
30 
60 

Ebb 
Ebb 
Ebb 
Ebb 

20.6 
21.1 
20  8 
20.6 

18 
20 
16 
16 

4.95 
4.79 
4  75 
4.84 

90 
88 
87 
89 

1258 
1259 
1260 
1261 

3.18 
3.21 
3.25 
3.30 

Yt  way  across  

Yi  way  across  

Yi  way  across  

Y±  way  across  

40  36  25 
40  36  25 
40  36  25 
40  36  23 

74  02  48 
74  02  48 
74  02  48 
74  03  02 

1 

30 
60 
1 

Ebb 
Ebb 
Ebb 
Ebb 

21.1 

20.8 
20.6 
21.4 

20 
18 
18 
21 

4.84 
5.23 
5.10 
5.15 

89 
95 
91 
95 

1262 
1263 
1264 
1265 
1266 

3.35 
3.40 
3.45 
3.50 
3.55 

M  way  across  

%  way  across  

200  feet  off  Fort  Wadsworth  

200  feet  off  Fort  Wadsworth  

200  feet  off  Fort  Wadsworth  

40  36  23 
40  36  23 
40  36  21 
40  36  21 
40  36  21 

74  03  02 
74  03  02 
74  03  12 
74  03  12 
74  03  12 

30 
60 
1 
18 
40 

Ebb 
Ebb 
Ebb 
Ebb 
Ebb 

20.8 
20.6 
21.1 
20.6 
20.6 

18 
16 
26 
20 
18 

3.85 
4.86 
4.14 
4.69 
4.55 

70 
89 
75 
86 
83 

28— EAST  RIVER  TO  NARROWS,  MIDSTREAM.    JULY  26,  1913 

Low  water  occurred  at  Governors  Island  at  7.00  A.  M.    High  water  at  1.45  P.  M.    The  wind  was  northwest,  with  a  velocity 
of  5  to  10  miles  per  hour. 

1267 
1268 
1269 
1270 

A.  M. 
7.00 
7.05 
7.10 
7.28 

East  river,  at  Brooklyn  Bridge  

East  river,  at  Brooklyn  Bridge  

East  river,  at  Brooklyn  Bridge  

Hudson  river,  at  Pier  A  

40  42  20 
40  42  20 
40  42  20 
40  42  19 

73  59  48 
73  59  48 

73  59  48 

74  01  34 

1 

15 
36 
1 

Flood 
Flood 
Flood 
Flood 

21.7 
21.1 
21.1 
21.1 

25 
25 
28 
36 

1.20 
1.10 
1.35 
2.70 

22 
20 
24 
48 

1271 
1272 
1273 
1274 

7.33 
7.37 
8.05 
8.10 

Hudson  river,  at  Pier  A  

Robbins  Reef,  at  bell  buoy  

Robbins  Reef,  at  bell  buoy  

40  42  19 
40  42  19 
40  39  15 
40  39  15 

74  01  34 
74  01  34 
74  03  50 
74  03  50 

18 
36 
1 
30 

Flood 
Flood 
Flood 
Flood 

21.1 
21.1 
21.1 
20.8 

34 
32 
28 
26 

2.03 
2.54 
2.10 
2.40 

36 
45 
38 
43 

1275 
1276 
1277 
1278 

8.15 
8.40 
8.45 
8.50 

Robbins  Reef,  at  bell  buoy  

Kill  van  Kull,  at  Sailors  Snug  Harbor. 
Kill  van  Kull,  at  Sailors  Snug  Harbor. 
Kill  van  Kull,  at  Sailors  Snug  Harbor. 

40  39  15 
40  38  50 
40  38  50 
40  38  50 

74  03  50 
74  06  25 
74  06  25 
74  06  25 

45 
1 

15 
25 

Flood 
Flood 
Flood 
Flood 

20.8 
21.9 
21.7 
21.7 

26 
27 
27 
27 

2.86 
3.60 
3.10 
3.25 

51 
66 
57 
59 

696  DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

TABLE  CXXV— Continued 


28 — EAST  RIVER  TO  NARROWS,  MIDSTREAM.    JULY  25,  1913— Continued 


Sample 
No. 

Hour 
A.  M. 

Location  of  Samples 

Feet 
below 
surface 

Tidal 
current 

Temp, 
water 
Deg.  C. 

Per 

cent, 
land 
water 

Ox; 

C.  C. 
per 
litre 

fgen 

Per 
cent 
satura- 
tion 

Approximate 

Latitude 

Longitude 

1279 

1  OQCl 

1281 
1282 

9.30 

n  o*7 

9.40 
P.  M. 
12.25 

Narrows,  between  forts  

Narrows,  between  forts  

Narrows,  between  forts  

East  river,  at  Brooklyn  Bridge  

O        t  If 

40  36  25 
40  36  25 
40  36  25 

40  42  20 

O         t  If 

74  02  48 
74  02  48 
74  02  48 

73  59  48 

1 

30 
60 

1 

Flood 
ilood 
Flood 

Ebb 

21.7 
21 . 1 
20.8 

22.2 

25 
20 
18 

29 

3.10 
3.40 
4.05 

2.60 

57 
62 
74 

47 

1284 
1285 
1286 

1  o  on 

12.35 
12.55 
1.00 

East  river,  at  Brooklyn  Bridge  

East  river,  at  Brooklyn  Bridge  

Hudson  river,  at  Pier  A  

Hudson  river,  at  Pier  A  

40  42  20 
40  42  20 
40  42  19 
40  42  19 

73  59  48 

73  59  48 

74  01  34 
74  01  34 

15 
36 
1 
18 

Ebb 
Ebb 
Ebb 
Ebb 

21 .9 
21.7 

22.8 
22.2 

27 
28 
30 
29 

2.40 
2.45 
2.88 
2.53 

44 
44 
53 
50 

1287 
1288 
1289 
1290 

1.05 
1.40 
1.45 
1.50 

Hudson  river,  at  Pier  A  

Robbins  Reef,  at  bell  buoy  

Robbins  Reef,  at  bell  buoy  

Robbins  Reef,  at  bell  buoy  

40  42  19 
40  39  15 
40  39  15 
40  39  15 

74  01  34 
74  03  50 
74  03  50 
74  03  50 

36 
1 
30 
45 

Ebb 
Ebb 
Ebb 
Ebb 

21.7 
21.7 
21.1 

20.6 

29 
17 
18 
16 

2.51 
3.80 
3.80 
4.35 

45 
70 
70 
80 

1291 
1292 
1293 
1294 

2.10 
2.15 
2.20 
3.00 

Kill  van  Kull,  at  Sailors  Snug  Harbor. 
Kill  van  Kull,  at  Sailors  Snug  Harbor. 
Kill  van  Kull,  at  Sailors  Snug  Harbor . 
Narrows,  between  forts  

40  38  50 
40  38  50 
40  38  50 
40  36  25 

74  06  25 
74  06  25 
74  06  25 
74  02  48 

1 
15 
25 

1 

Ebb 
Ebb 
Ebb 
Ebb 

22.2 
22.0 
21.1 
21.1 

27 
26 
20 
20 

2.80 
3.30 
3.65 
4.10 

51 
60 
67 
75 

1295 
1296 

3.15 
3.25 

40  36  25 
40  36  25 

74  02  48 
74  02  48 

30 
60 

Ebb 
Ebb 

21.1 
21.1 

18 
18 

4.30 
5.25 

79 
96 

29— HARLEM  RIVER,  BACK  OF  WARDS  ISLAND.    AUGUST  14,  1913 

High  water  occurred  at  Governors  Island  at  6.50  A.  M.    The  wind  was  south,  with  a  velocity  of  5  miles  per  hour. 

1297 
1298 

P.  M. 
12.35 
12.50 

40  47  23 
40  47  23 

73  56  07 
73  56  07 

24 
2 

Ebb 
Ebb 

23.3 
23.9 

20 
23 

2.60 
1.40 

49 
26 

30— EAST  RIVER,  PIER  10.    AUGUST  16,  1913 

High  water  occurred  at  Governors  Island  at  7.45  A.  M.    Low  water  at  1.45  P.  M.    The  wind  was  south,  with  a  velocity  of  3 
miles  per  hour. 

1299 

A.  M. 
11.45 

Midstream  

40  42  03 

74  00  11 

20 

Ebb 

23.9 

23 

2.05 

39 

31— EAST  RTVER.    AUGUST  21,  1913 

High  water  occurred  at  Governors  Island  at  10.55  P.  M.    The  wind  was  southeast,  with  a  velocity  of  10  miles  per  hour. 

1302 
1303 

1304 
1305 

A.  M. 
11.15 
11.45 
P.  M. 
12.10 
12.35 

East  river,  at  Mill  Rock  

Midstream,  at  Queensboro  Bridge. . . . 

Midstream,  at  Williamsburgh  Bridge. . 
Midstream,  at  Brooklyn  Bridge  

40  46  50 
40  45  25 

40  42  49 
40  42  20 

73  56  25 
73  57  55 

73  58  21 
73  59  48 

24 
24 

24 
24 

Flood 
Flood 

Flood 
Ebb 

21.7 
23.9 

23.3 
23.3 

21 

20 

20 
20 

2.88 
3.38 

2.08 
2.18 

53 
65 

39 
41 

DISSOLVED  OXYGEN  IN  THE  WATER 


697 


TABLE  CXXV— Continued 

32— EAST  RIVER,  HUDSON  RIVER,  ROBBINS  REEF,  KILL  VAN  KULL  AND  NARROWS.    AUGUST  27,  1913 


Low  water  occurred  at  Governors  Island  at  10.00  A.  M.  High  water  at  4.10  P.  M.  The  wind  was  south,  with  a  velocity 
of  3  to  10  miles  per  hour. 


Sample 
No. 

Hour 
A.  M. 

Location  of  Samples 

Feet 
below 
surface 

Tidal 
current 

Temp, 
water 
Deg. 

Per 

cent, 
land 
water 

Ox 

C.  C. 
per 
litre 

ygen 

Per 
cent, 
satura- 
tion 

Approximate 

Latitude 

Longitude 

1306 
1307 
1308 
1309 

9.00 
9.10 
9.20 
9.35 

East  river,  midstream,  at  Brooklyn 
Bridge  

East  river,  midstream,  at  Brooklyn 
Bridge  

East  liver,  midstream,  at  Brooklyn 
Bridge 

Hudson  river,  midstream,  off  Pier  A. . . 

o      /  w 

40  42  20 

40  42  20 

40  42  20 
40  42  19 

73  59  48 
73  59  48 

73  59  48 

74  01  34 

1 

18 

30 
1 

Ebb 

Ebb 

Ebb 
Ebb 

23.6 

23.6 

23.6 
23.3 

21 
21 

21 

26 

0.90 

1.15 

1.34 
3.04 

17 

22 

25 
57 

1310 
1311 
1312 
1313 

9.45 
9.55 
10  25 
10.30 

Hudson  river,  midstream,  off  Pier  A  .  . 
Hudson  river,  midstream,  off  Pier  A  .  . 

Robbins  Reef,  near  bell  buoy  

Robbins  Reef,  near  bell  buoy  

40  42  19 
40  42  19 
40  29  10 
40  29  10 

74  01  34 
74  01  34 
74  03  50 
74  03  50 

18 
36 
1 
24 

Ebb 
Ebb 
Flood 
Flood 

23.3 
23.3 
23.3 
23.3 

28 
26 
21 
21 

2.68 
3.09 
2.90 
2.86 

49 
58 
55 
54 

1314 
1315 

1316 

1317 

10.50 
11.10 

11.15 

11.25 

Robbins  Reef,  near  bell  buoy  

Kill  van  Kull,  midstream,  opposite 

Sailors  Snug  Harbor  

Kill  van  Kull,  midstream,  opposite 

Kill  van  Kull,  midstream,  opposite 
Sailors  Snug  Harbor  

40  29  10 
40  38  50 
40  38  50 

A.\J      KJyJ  *J\J 

40  38  50 

74  03  50 
74  06  25 
74  06  25 

1    i      \J\J  *mt%J 

74  06  25 

48 
1 

15 
30 

Flood 
Flood 
Flood 
Flood 

23.8 
23.3 
23.3 
23.3 

24 
23 
23 
23 

2.90 
4.30 
3.66 
3.40 

54 
81 
69 
64 

1318 

1319 
1320 
1321 

12.00 
P.  M. 
12.10 
12.15 
2.15 

Narrows,  midway,  between  forts  

Narrows,  midwav,  between  forts  

Narrows,  midway,  between  forts  

T^n^t    nvpr    miHstrpflm     at  nrnnlclvn 

Bridge  

40  36  25 

40  36  25 
40  36  25 

40  42  20 

74  02  48 

74  02  48 
74  02  48 

73  59  48 

1 

36 
54 

1 

Flood 

Flood 
Flood 

Flood 

23.3 

22.8 
22.8 

23.3 

22 

18 
18 

26 

2.90 

3.64 
4.30 

2.00 

55 

66 
79 

38 

1322 

1323 

1324 
1325 

2.20 

2.30 

2.50 
2.55 

East  river,  midstream,  at  Brooklyn 
Bridge  

East  river,  midstream,  at  Brooklyn 
Bridge  

Hudson  river,  midstream,  off  Pier  A . . 

Hudson  river,  midstream,  off  Pier  A .  . 

40  42  20 

40  42  20 
40  42  19 
40  42  19 

73  59  48 

73  59  48 

74  01  34 
74  01  34 

18 

30 
1 
18 

Flood 

Flood 
Flood 
Flood 

23.3 

23.3 
23.3 
23.3 

26 

26 
26 
24 

1.96 

2.40 
2.40 
3.16 

36 

45 
45 
59 

1326 
1327 
1328 
1329 

3.00 
3.45 
3.55 
4.05 

Hudson  river,  midstream,  off  Pier  A .  . 

Robbins  Reef,  near  bell  buoy  

Robbins  Reef,  near  bell  buoy  

Robbins  Reef,  near  bell  buoy  

40  42  19 
40  39  10 
40  39  10 
40  39  10 

74  01  34 
74  03  50 
74  03  50 
74  03  50 

36 
1 
24 
48 

Flood 
Ebb 
Ebb 
Ebb 

23.3 
22.8 
22.8 
22.8 

24 
18 
16 
14 

2.70 
3.30 
3.27 
4.10 

51 
62 
62 
79 

1330 
1331 
1332 
1333 

4.30 
4.35 
4.40 
5.40 

Kill  van  Kull,  midstream,  opposite 
Sailors  Snug  Harbor  

Kill  van  Kull,  midstream,  opposite 
Sailors  Snug  Harbor  

Kill  van  Kull,  midstream,  opposite 
Sailors  Snug  Harbor  

Narrows,  midway  between  forts  

40  38  50 

40  38  50 

40  38  50 
40  36  25 

74  06  25 

74  06  25 

74  06  25 
74  02  48 

1 

15 

30 
1 

Ebb 

Ebb 

Ebb 
Ebb 

23.3 

23.0 

22.8 
22.8 

20 

20 

18 
16 

3.30 

3.26 

3.50 
4.60 

63 

61 

66 
87 

1334 
1335 

5.45 
5.50 

Narrows,  midway  between  forts  

Narrows,  midway  between  forts  

40  36  25 
40  36  25 

74  02  48 
74  02  48 

36 
54 

Ebb 
Ebb 

22.6 
22.2 

16 
16 

4.87 
5.20 

92 
99 

33— EAST  RIVER,  HUDSON  RIVER,  ROBBINS  REEF,  KILL  VAN  KULL  AND  NARROWS.    SEPTEMBER  19,  1913. 

High  water  occurred  at  Governors  Island  at  10.40  A.  M.    Low  water  at  4.30  P.  M.    The  wind  was  northeast,  with  a  velocity 
of  5  miles  per  hour. 

1339 
1340 

A.  M. 
9.05 

9.15 

East  river,  midstream,  at  Brooklyn 

Bridge  

East  river,  midstream,  at  Brooklyn 

40  42  20 
40  42  20 

73  59  48 
73  59  48 

1 

18 

Flood 
Flood 

20.0 
20.0 

25 
25 

2.30 
2.20 

41 

39 

698 


DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


TABLE  CXXV— Continued 


33— EAST  RIVER,  HUDSON  RIVER,  ROBBINS  REEF,  KILL  VAN  KULL  AND  NARROWS. 

SEPTEMBER  19,  1913— Continued 


Sample 
No. 

Hour 
A.  M. 

Location  of  Samples 

Feet 
below 
surface 

Tidal 
current 

Temp, 
water 
Deg.  C. 

Per 
cent, 
land 

WaLci 

Ox} 

C.  C. 
per 
litre 

'gen 

Per 

cent. 

aal/Ura- 

tion 

Approximate 

Latitude 

Longitude 

1341 
1-342 

9.20 
9.50 

East  river,  midstream,  at  Brooklyn 
Bridge. ...   

Hudson   river,   midstream,  opposite 
Pier  A  

O        t  If 

40  42  20 
40  42  19 

O        /  0 

73  59  48 

74  01  34 

36 
1 

Flood 
Flood 

20.0 
19.7 

25 
25 

1.90 
2.70 

33 
49 

1343 

1344 

1345 
1346 

10.00 

10.05 

10.45 
10.50 

Hudson   river,    midstream,  opposite 

TV  A 

Pier  A  

Hudson   river,    midstream,  opposite 

Pier  A  

Robbins  Reef,  at  bell  buoy  

Robbins  Reef,  at  bell  buoy  

40  42  19 

40  42  19 
40  39  15 
40  39  15 

74  01  34 

74  01  34 
74  03  50 
74  03  50 

18 

36 
1 

30 

Flood 

Flood 
Ebb 
Ebb 

19.7 

19.5 
19.1 
19.1 

25 

25 
18 
18 

2.30 

2.80 
4.00 
4.20 

40 

50 
71 
74 

1347 
1348 

1349 

1350 

11.00 
11.30 

11.35 

11.40 

Robbins  Reef,  at  bell  buoy  

Kill  van  Kull,  midstream,  off  Sailors 

Snug  Harbor  

Kill  van  Kull,  midstream,  off  Sailors 

Snug  Harbor  

Kill  van  Kull,  midstream,  off  Sailors 

Snug  Harbor  

40  39  15 
40  38  50 
40  38  50 
40  38  50 

74  03  50 
74  06  25 
74  06  25 
74  06  25 

48 
1 
18 

36 

Ebb 
Ebb 
Ebb 
Ebb 

18.9 
19.4 
19.4 
19.4 

18 
23 
21 
21 

4.18 
2.70 
3.20 
3.12 

73 
47 
56 
55 

1351 
1352 
1353 
1354 

P  M 
12.15 
12.25 
12.30 
1.40 

Narrows,  midstream,  between  forts. . . 
Narrows,  midstream,  between  forts. . . 
Narrows,  midstream,  between  forts. . . 
East  river,  midstream,  at  Brooklyn 
Bridge  

40  36  25 
40  36  25 
40  36  25 

40  42  20 

74  02  48 
74  02  48 
74  02  48 

73  59  48 

1 

36 
54 

1 

Ebb 
Ebb 
Ebb 

Ebb 

19.0 
19.0 
19.0 

19.4 

16 
13 
13 

21 

4.60 
4.90 
5.12 

2.00 

82 
88 
90 

35 

1355 
1356 
1357 
1358 

1.45 
1.55 
2.15 
2.20 

East  river,  midstream,  at  Brooklyn 

Bridge  

East  river,  midstream,  at  Brooklyn 

Bridge  

Hudson   river,   midstream,  opposite 

Pier  A  

Hudson   river,    midstream,  opposite 

Pier  A  

40  42  20 
40  42  20 
40  42  19 
40  42  19 

73  59  48 

73  59  48 

74  01  34 
74  01  34 

18 
36 
1 

18 
lo 

Ebb 
Ebb 
Ebb 

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19.7 
19.7 
19.4 

1Q  9 

25 
25 
23 

— 

2.00 
1.99 
3.20 

35 
35 
57 
fift 

62 
fid 

66 
73 

1359 

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1361 
1362 

2.30 

z .  oo 
3.00 
3.10 

Hudson   river,    midstream,  opposite 

Pier  A  

Robbins  Reef,  near  bell  buoy  

Robbins  Reef,  near  bell  buoy  

40  42  19 
40  39  15 
40  39  15 
40  39  15 

74  01  34 
74  03  50 
74  03  50 
74  03  50 

36 

30 
48 

Ebb 

Ebb 
Ebb 

19.2 

1  Q  9 
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18.9 
19.2 

21 

17 

17 
17 

3.51 

'x  fin 

3.70 
4.10 

1363 
1364 
1365 
1366 

3.35 
3.45 
3.50 
4.25 

Kill  van  Kull,  midstream,  opposite 
Sailors  Snug  Harbor  

Kill  van  Kull,  midstream,  opposite 
Sailors  Snug  Harbor  

Kill  van  Kull,  midstream,  opposite 
Sailors  Snug  Harbor  

Narrows,  midstream,  between  forts.  . . 

40  38  50 

40  38  50 

40  38  50 
40  36  25 

74  06  25 

74  06  25 

74  06  25 
74  02  48 

1 

18 

36 
1 

Ebb 

Ebb 

Ebb 
Flood 

19.2 

19.4 

19.4 
19.2 

27 

27 

27 
21 

3.10 

3.30 

3.50 
3.40 

54 
58 

61 

60 

1367 
1368 

4.30 
4.35 

Narrows,  midstream,  between  forts.  .  . 
Narrows,  midstream,  between  forts.  .  . 

40  36  25 
40  36  25 

74  02  48 
74  02  48 

36 
54 

Flood 
Flood 

19.2 
19.2 

17 
21 

3.60 
3.60 

64 
60 

DISSOLVED  OXYGEN  IN  THE  WATER 
TABLE  OXXVI 


699 


Average  Volume  and  Percentage  of  Saturation  of  Dissolved  Oxygen  in  the  Water  in  the  Year  1913 

Averages  for  various  parts  of  the  harbor 

Data  for  this  table  are  contained  in  Table  CXXV. 


Location 


Number 
of 

analyses 


Averages : 

C.  C. 
per  litre 


Averages : 
per  cent, 
saturation 


Samples  included  in  the  averages 


Upper  bay  

Hudson  river,  below 
Spuyten  Duyvil. . 

Hudson  river,  above 
Spuyten  Duyvil.  . 

East  river,  below 
Hell  Gate  

East    river,  above 

Hell  Gate  

Harlem  river  

Kill  van  Kull  

The  Narrows  

Gowanus  canal  

Nfewtown  creek  

Wallabout  canal .... 


65 

171 

84 
260 


4.21 

3.33 

4.65 
2.53 


70 

54 

81 
43 


317-318,  327-328,  337-338,  347-348,  391-393,  406-408,  418-420,  433- 
435,  796-822,  1273-1275,  1288-1290,  1312-1314,  1327-1329,  1345- 
1347,  1360-1362. 

315-316,  325-326,  335-336,  349-350,  354,  366-371,  379-384,  394-396, 
409-411,  415^17,  430-432,  706-795,  1087-1116,  1270-1272,  1285- 
1287,  1309-1311,  1324-1326,  1342-1344,  1357-1359. 

1003-1086. 

313-314,  323-324,  333-334,  351-352,  355,  358-365,  377-378,  397-399, 
412-414,  427-429,  443-537,  613-636,  1117-1206,  1267-1269,  1282- 
1284,  1299,  1302-1308,  1321-1323,  1339-1341,  1354-1356,  (442  too 
near  sewer,  not  included). 


153 
27 
110 


3.80 
1.70 
3.85 


67 
29 
66 


643-705,  895-984. 

353,  637-642,  985-1002,  1297-1298. 

319-320,  329-330,  339-340,  345-346.  388-390,  403-405,  421-423,  436- 
438,  823-894,  1276-1278,  1291-1293,  1315-1317,  1330-1332,  1348- 
1350,  1363-1365. 


173 


2 
3 
2 


4.10 


4.80 
1.40 
4.68 


73 


63 
18 
61 


321-322,  331-332,  341-344,  385-387,  400-402,  424-426,  439-441,  538- 
612,  1207-1266,  1279-1281,  1294-1296,  1318-1321,  1333-1335,  1351- 
1353,  1366-1368. 

356-357. 

374-376. 

372-373. 


700 


DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


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702  DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

TABLE  CXXVIII 

Average  Volume  and  Percentage  of  Saturation  of  Dissolved  Oxygen  in  the  Water  in  the  Year  1913 
Averages  of  samples  taken  on  Ebb  and  Flood  Currents  for  various  parts  of  the  harbor 

Data  for  this  table  are  contained  in  Table  CXXV. 


Location 


Upper  bay . 


Hudson  river,  below 
Spuy ten  Duyvil . . . 


Hudson  river,  above 
Spuy  ten  Duyvil . . . 

East  river,  below  Hell 
Gate  

East  river,  above  Hell 

Gate  

Harlem  river  

Kill  van  Kull  

The  Narrows  

Gowanus  canal  

Newtown  creek  

Wallabout  canal  


Currents 


Ebb  Currents 


O  w 
.  >> 


34 


109 


30 


129 


72 
26 


64 


91 


O 

?.$ 

I-  O. 

< 


4.51 


3.55 


4.15 


2.69 


3.97 
1.56 


3.82 
4.33 


4.80 
1.40 
4.68 


75 


59 


72 


45 


70 

28 


66 
77 


63 
18 
61 


Samples  included  in  the  averages 


327-328,  337-338,  406-408,  433-435 
811-822,  1288-1290,  1312-1314, 
1345-1317,  1360-1362. 

325-326,  335-336,  366-371,  379-384 
409-411, 745-795, 1087-1116, 1285- 
1287,  1309-1311,  1357-1359. 

1018-1047. 


323-324,  333-334,  355,  360-365,  377- 
378,  451-480,  529-537,  613-636 
1132-1173,  1282-1284,  1299,  1305- 
1308,  1354-1356. 


679-705,  895-939. 

637-642,  985-1002,  1297-1298. 


329-330,  339-340,  403^05,  436-438, 
823-828, 859-894, 1291-1293, 1330- 
1332,  1348-1350,  1363-1365. 
331-332,  341-342,  400-402,  439-441, 
538-579,    1237-1266,  1279-1281, 
1333-1335,  1351-1353. 
356-357. 
374-376. 
372-373. 


Flood  Currents 


O  vi 

.  >> 


31 


62 


54 


131 


81 
1 


40 


82 


O 

O  9. 


d>  — ' 
ho  u 

> 


3.89 


2.92 


4.93 


o5  3 


5  o 


63 


48 


85 


2.38  40 


3.64 
5.40 


3.1 
3.85 


64 
68 


66 


68 


Samples  included  in  the  averages 


317-318,  347-348,  391-393,  418-420, 
796-810,  1273-1275,  1327-1329. 


315-316,  349-350,  354,  394-396,  415- 
417,  430-432,  706-744,  1270-1272, 
1324-1326,  1342-1344. 

1003-1017,  1048-1086. 


313-314,  351-352,  358-359,  397-399, 
412-414,  427-429,  443-450,  481- 
528,  1117-1131,  1174-1206,  1267- 
1269,  1302-1304,  1321-1323,  1339- 
1341. 

643-678,  940-984. 
353. 


319-320,  345-346,  388-390,  421-423, 
829-858,  1276-1278,  1315-1317. 

321-322,  343-344,  385-387,  424-426, 
580-612,    1207-1236,  1279-1281, 
1318-1320,  1366-1368. 
No  flood  samples. 
No  flood  samples. 
No  flood  samples. 


DISSOLVED  OXYGEN  IN  THE  WATER 


703 


TABLE  CXXIX 

Average  Volume  and  Percentage  of  Saturation  of  Dissolved  Oxygen  in  the  Water  in  the  Year  1913 

Summary  of  Tables  CXXVI,  CXXVII  and  CXXVIII 

Data  for  this  table  are  contained  in  Table  CXXV. 


Location 


All  Depths 
and  Tides 


oj 
O  cn 
.  >> 


o 

d* 
•  • 

cn  •  ~ 
oj  ~* 
bC  u 

09  «> 

< 


<~  s 

OJ  O 

w& 

..  09 

cn 

0)  3 

09  S 


<;  cj 


Depths 


Surface 


►5  "3 


o 
•  • 

cn  ■  — 
oj  ~ ' 
tf  u 


>  -g 
<5  g 


Mid-depth 


cn 

<  oj 

O  tn 
.  >. 


o 

O  £ 
•  •  *i 

OJ  — " 

M  t- 

09  0) 
i-.  C 

CD 
> 


H  S 

oj  o 
a*3 

..  09 

tn 

OJ  3 

c9  09 

t,  IK 

<C  0J 


Bottom 


cn 
O  cn 


Q 

rj  oj 


OJ 

> 


S  o 

..  09 

cn  S" 

a  s 

OJ  +3 

<J  OJ 

^  CJ 


Currents 


Ebb 


OJ 
O  cn 
.  >> 


Q 

d  « 


tn  13 

oj 

I* 

h,  P. 
oj 
> 


^  s 

oj  O 
O-VB 

..  09 

tn  t 

OJ  3 

09  03 


^  g 


Flood 


d  » 


tn 

oj  ~ 

it  t. 

09  OJ 

< 


oj  o 

..  oj 

CD  H 

oj  3 
UJ-w 

09  09 

U,  CD 

■<  OJ 


Upper  bay  

Hudson  river,  below  Spuyten  Duyvil 
Hudson  river,  above  Spuyten  Duyvil 

East  river,  below  Hell  Gate  

East  river,  above  Hell  Gate  


65 
171 

84 
260 
153 


.21 

.33 
4.65 
2.53 
3.80 


70 
54 
81 
43 
67 


23 
63 
28 
93 
51 


4.09 

3.56 
4.80 
2.70 
3.64 


66 
57 
83 
43 
64 


19 

52 
28 
84 
51 


3.93 
3.10 
4.57 
2.26 
3.76 


69 
53 
79 
40 
67 


23 
56 
28 
83 
51 


4.57 
3.27 
4.59 
2.62 
3.98 


74 

54 
80 
46 
70 


34 
109 

30 
129 

72 


4.51 
3.55 
4.15 
2.69 
3.97 


75 
59 
72 
45 
70 


31 
62 
54 
131 
81 


3.89 
2.92 
4.93 
2.38 
3.64 


63 
48 
85 
40 
64 


Harlem  river. 
Kill  van  Kull. 
The  Narrows. 


27 
110 
173 


Gowanus  canal. 


Newtown  creek. 


Wallabout  canal . 


1.70 
3.85 
4.10 

4.80 


1.40 


4.68 


29 
66 
73 

63 


IS 


61 


10 

38 
59 


1.80 
3.89 
3.95 

4.80 


1.40 

4.68 


29 
65 
69 

63 


18 
61 


34 
55 

m 
6 

111 

e 

m 

s 


1.56 
3.58 
3.91 

No 
id-d 
amp 

No 
id-d 
amp 

No 
id-d 
amp 


28 
64 
71 

epth 
les. 

epth 
les. 

epth 
les. 


9 

38 
59 


1.71 

4.05 
4.43 

No 
amp 

No 
amp 

No 
amp 


31 

68 
78 

deep 
les. 

deep 
les. 

deep 
les. 


26 
64 
91 


1.56 
3.82 
4.33 

4.80 
1.40 
4.68 


28 
66 
77 

63 


18 


61 


1 

46 
82 

/  N 

\  8 

/  N 

\  8 

/  N 

\  8 


5.40 
3.89 
3.85 

o  flo 
amp 

o  flo 
amp 

o  flo 
amp 


68 
66 
68 

od 
les. 

od 
les. 

od 
les. 


Note. — Total 


1050 
1 

2 
3 


1056 


Number  of  samples  included  in  the  averages. 

No.  442  not  used,  being  too  near  Manhattan  sewer  outlet  at  Brooklyn  Bridge. 
Nos.  1300-1301  not  used,  because  aerated  before  analysis. 

Nos.  1336r1338  not  used,  as  they  apply  to  harbor  water  in  general,  and  to  no  particular 
locality. 

Total  analyses  during  1913,  Nos.  313-1368. 
Series  for  1913  begins  with  sample  No.  313. 


704 


DATA  KELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


INTRODUCTION  TO  TABLE  CXXX 

In  the  year  1913,  the  same  attention  was  given  to  the  collection  of  samples  in  cross- 
sections  of  the  main  tidal  channels  in  different  parts  of  the  harbor  as  characterized  the 
work  in  1911.  The  method  of  collecting  samples  in  cross-sections  was  the  same  as  that 
followed  in  1911,  and  described  in  the  introduction  to  Table  XXVIII,  Report  of  Metro- 
politan Sewerage  Commission,  1912,  pages  415-416. 

Table  CXXX  contains  a  summary  of  averages  of  the  oxygen  found  at  various  cross- 
sections  in  the  year  1913,  on  the  ebb  currents,  the  flood  currents,  and  without  regard  to 
current  direction. 


DISSOLVED  OXYGEN  IN  THE  WATER  705 

TABLE  CXXX 

Average  Volume  and  Percentage  of  Saturation  of  Dissolved  Oxygen  in  the  Water  in  the  Year  1913 
Averages  of  Samples  taken  in  the  Cross-sections  of  the  Tidal  Channels 


Data  for  this  table  are  contained  in  Table  CXXV. 


Dissolved  Oxygen 

l\  UIIlUcI 

Date 

Kn  Tin  nlna 

Location 

Both 

Currents 

Ebb 

Current 

Flood 

Current 

of 

1  01 S 

included  in 

Samples 

J.  Jl  o 

the  averages 

n    <~"  Par 

l^.  Ky.  rev 

rer  i^eni. 

C.  C.  Per 

Per  Cent 

i  >,-,r  t  \ui  t 
rer  ^enu 

Litre 

Litre 

Saturation 

Litre 

■  .UN]   \  1  M  IT  1 

XlUUbOU  Xivclj  ab  IVlt. 

St.  Vincent  

4.58 

80 

4.15 

72 

5.01 

87 

75 

July  16 

1003-1077. 

Hudson  river,  at  the 

dSi 

3.08 

55 

9  98 

d~\ 

on 
yu 

July  y 

ivo^t  yo. 

I  n ftrta  Wool/ 

l  nroggs  in  cck  .... 

d  ^ 

oU 

4.68 

82 

t .  oo 

79 

on 
yu 

July  ii 

oyo  yoi . 

East  river,  at  Law- 

rence Point  

2.76 

49 

2.79 

49 

2.72 

48 

63 

July  8 

643-705. 

East  river,  at  the 

2.21 

40 

2.43 

44 

1.98 

36 

87 

July  2 

451-537. 

2.32 

42 

2.51 

45 

2.14 

38 

90 

July  18 

1117-1206. 

2.26 

41 

2.47 

44 

2.06 

37 

177 

Kill  van  Kull,  at 

Sailors  Snug  Har- 

bor  

3.61 

65 

3.64 

66 

3.58 

65 

72 

July  11 

823-894. 

The  Narrows,  at  the 

Forts  

3.63 

67 

3.68 

68 

3.58 

65 

75 

July  3 

538-612. 

4.14 

77 

4.60 

84 

3.69 

70 

60 

July  24 

1207-1266. 

3.88 

72 

4.14 

76 

3.64 

67 

135 

Upper  bay,  in  vicin- 

ity   of  Robbins 

Reef  

3.78 

68 

4.42 

80 

3.13 

56 

27 

July  10 

796-822. 

Plate  C 


Percentage  of  Saturation  of 
Dissolved  Oxygen 
in  the  Water  of  New  York  Harbor 

in  1913 


V 


Plate  D 


Percentage  of  Saturation  of 
Dissolved  Oxygen 
in  the  Water  of  New  York  Harbor 
June  11th  to  July  25th,  1913 


DISSOLVED  OXYGEN  IN  THE  WATER 


707 


INTRODUCTION  TO  OXYGEN  DIAGRAMS 

From  the  data  contained  in  Table  CXXY  curves  have  been  drawn  to  show  the  varia- 
tions in  oxygen  which  occurred  in  one  tidal  cycle  in  the  cross-sections  of  the  Narrows, 
the  Hudson  river  at  the  mouth  and  at  Mt  St.  Vincent,  and  the  East  river  at  the  mouth 
and  at  Throgs  Neck,  in  the  year  1913,  after  the  same  manner  as  shown  for  the  year 
1911,  Report  of  Metropolitan  Sewerage  Commission,  1912,  pages  447-457 

Two  groups  of  curves  have  been  drawn  for  each  section.  In  one  the  ordinates 
represent  the  percentages  of  saturation  of  dissolved  oxygen  in  the  water  and  the  per- 
centages of  sea-water,  and  the  abscissae  the  hours  of  the  day.  Times  of  ebb  and  flood 
currents  are  indicated  on  the  curves.  Curves  have  been  drawn  for  each  of  the  three  or 
Ave  locations  at  which  samples  were  collected  in  the  cross-section,  the  heavy  lines 
representing  percentages  of  saturation  of  dissolved  oxygen,  and  the  light  lines  percent- 
ages of  sea-water. 

The  second  set  of  curves  has  been  drawn  to  show  the  variations  in  dissolved 
oxygen  and  percentage  of  sea-water  at  each  cross-section,  as  determined  by  each  set  of 
samples.    These  curves  approximately  indicate  lines  of  equal  oxygen  and  sea- water. 


708         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HABBOR 

7       8       9       10      II  A.M.  12        P.M.  2.       3      4       5  6 


c 

o 

o> 
_> 
o 

Q 


c 
g 

+- 
a 

+- 

D 


c 

a) 
o 
i_ 

0- 


RM.  2. 


FIG.  46 


Percentage  of  Saturation  of  Dissolved  Oxygen  in  Heavy  Lines,  and  Percentage  of  Sea 
Water  in  Light  Lines,  in  a  Cross-Section  of  the  Narrows  from  Fort  Wadsworth  to  Fort  Lafay- 
ette at  Various  Stages  of  Tide,  July  3,  1913.  The  Total  Number  of  Samples  included  is 
75.   The  Results  of  Analysis  are  indicated  by  Small  Circles,  Triangles  and  Squares. 


DISSOLVED  OXYGEN  IN  THE  WATER 


709 


FIG.  46— Continued 


Comparison  of  the  Curves  of  Data  for  the  Narrows  in  1911  and  1913. 

On  comparing  the  curves  made  from  data  collected  at  the  Narrows  in  1911  and 
1913,  various  interesting  points  of  similarity  and  difference  are  observable.  See  the 
following  diagrams  in  this  report  and  Oxygen  Diagrams  II  in  Part  III,  Chapter  III, 
p.  448,  of  the  Commission's  report  of  August,  1912. 

There  was  less  similarity  between  the  curves  at  the  various  stations  and  the  cross- 
sections  in  1913  than  in  1911. 

The  curve  representing  the  oxygen  at  depths  of  1  foot  shows  that  a  greater  range 
of  oxygen  values  existed  in  1913  than  in  1911,  and  there  was  less  agreement  with  the 
curves  at  the  other  depths  in  1913. 

The  curves  representing  the  conditions  at  mid-depth  and  bottom  were  not  as  nearly 
identical  in  1913  as  they  were  in  1911.  In  1913  the  changes  were  more  abrupt  than 
in  1911  and  not  simultaneous  at  different  stations  and  at  different  depths. 

In  both  years  there  was  a  similar  drop  in  the  percentage  of  oxygen  on  the  ebb  cur- 
rent, but  in  1913  it  was  greater  in  amount,  more  abrupt  and  did  not  follow  the  change 
of  current  from  flood  to  ebb  as  closely  as  it  did  in  1911. 


710         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


Ft  WaAsworth.  Ft.  Lafayette.    Ft.  Wadsworth.  Ft. Lafayette 


7-40  -  8-45  A.M.  12= 10  -  I  I  05  P. M. 

(15  Samples,  Nos.  538-552.)  (15  Samples,  Nos.  568-582.) 

Slack  Water  -  End  of  Flood  . Current.  4  Hours  After  Beginning  of  F_bb  Current. 


9:52-10:55  A.M.  2-25  -  3  •  40  P. M. 

(15  Samples. Nos.  553-567.)  (15  Samples,  Nos.  583-597.) 

2  Hours  After  Beginning  of  F_bb  Current  Beginning  of  Rood  Current. 


4-  40-  5-55  P.M. 
(15  Samples.  Nos.  538-612.) 

2£  Hours  After  Beqinning  of  Flood  Current. 
FIG.  47 

Cross-Section  of  the  Narrows  from  Fort  Wadsworth  to  Fort  Lafayette,  showing  Percentage  of  Saturation 
of  Dissolved  Oxygen  in  Full  Lines  and  Percentage  of  Sea  Water  in  Broken  Lines,  at  Various  Stages  of  Tide, 
July  3, 1913.    The  Total  Number  of  Samples  included  is  75.    Sampling  Points  are  indicated  by  Small  Circles. 


8 


DISSOLVED  OXYGEN  IN  THE  WATER 
9       10      II  AM  12       IPM    2       3  4 


711 
6  7 


FIG.  48 

Percentage  of  Saturation  of  Dissolved  Oxygen  in  Heavy  Lines,  and  Percentage  of  Sea  Water  in 
Light  Lines,  in  a  Cross-Section  of  the  Mouth  of  the  Hudson  River,  from  Pier  A,  Manhattan,  to  C.  R.R. 
of  N.  J.  Terminal,  Jersey  City,  at  Various  Stages  of  Tide,  July  9,  1913.  The  Total  Number  of 
Samples  included  is  90.  The  Results  of  Analysis  are  indicated  by  Small  Circles,  Triangles  and 
Squares. 


712         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


C 

u 
u 
0) 
Q_ 


FIG.  48— Continued 


Comparison  of  the  Curves  for  the  Mouth  of  the  Hudson  in  1911  and  1913. 

Comparing  the  foregoing  curves  with  those  recorded  for  the  same  section  in  1911, 
the  following  deductions  can  be  made.  The  1911  curves  can  be  found  in  the  report  of 
this  Commission,  dated  August,  1912,  Part  III,  Chapter  III,  p.  450. 

The  curves  of  the  1913  observations  are  more  irregular,  show  more  abrupt  changes 
and  cover  a  wider  range  of  values  than  those  of  1911. 

The  general  trend  of  the  1-foot  depth  curve  is  followed  by  the  mid-depth  and  bot- 
tom curves,  though  not  so  closely  as  in  1911. 

In  1913  there  was  the  same  rise  of  oxygen  values  toward  the  end  of  the  flood  as 
in  1911,  but  it  was  more  abrupt  and  did  not,  as  a  rule,  reach  a  maximum  until  after 
the  turn  of  the  current  to  ebb. 

The  decrease  in  oxygen  values,  which,  in  the  1911  curves,  commenced  with  the 
slack  before  ebb  and  gradually  continued,  was  abrupt  in  1913  and  delayed  until  about 
the  strength  of  the  ebb  current. 


DISSOLVED  OXYGEN  IN  THE  WATER 


713 


714         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 
7       8       3       10       IIA.M.  \Z       IP.M.  2       3  4-56 


II  AM.  12.        P.M.  a 
FIG.  60 

Percentage  of  Saturation  of  Dissolved  Oxygen  in  Heavy  Lines,  and  Percentage  of  Sea  Water 
in  Light  Lines,  in  a  Cross-Section  of  the  Mouth  of  the  East  River  from  Pier  10,  Manhattan,  to 
Pier  10,  Brooklyn,  at  Various  Stages  of  Tide,  July  2, 1913.  The  Total  Number  of  Samples  included 
is  90.   The  Results  of  Analysis  are  indicated  by  Small  Circles,  Triangles  and  Squares. 


DISSOLVED  OXYGEN  IN  THE  WATER 


715 


FIG.  50— Continued 


Comparison  of  the  Curves  for  the  Mouth  of  the  East  River  in  1911  and  1913 


On  comparing  the  curves  published  in  the  Commission's  1912  report,  Part  III, 
Chapter  III,  p.  452,  with  the  foregoing  curves  for  the  same  section,  the  following 
points  become  apparent. 

The  range  of  oxygen  values  in  1911  was  scarcely  10  per  cent.,  whereas  in  1913  it 
was  nearly  50  per  cent,  of  the  saturation  value. 

In  1911  the  curves  were  regular,  showing  a  uniform  rise  during  the  flood  current 
and  a  decrease  in  oxygen,  though  less  gradual,  throughout  the  ebb.  In  1913  there  was 
a  decrease  in  oxygen,  though  much  more  rapid  and  less  concordant  at  the  different 
depths  throughout  the  ebb  current  than  in  1911.  In  1913  the  general  tendency  of  the 
bottom  and  mid-depth  curves  on  the  flood  current  was  to  rise,  while  the  surface  curve 
rose  rapidly  to  a  maximum  and  fell  off  again. 


716         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


Manhattan. 
Pier  10 


Brooklyn. 
Pier  10 


7  =  25  "8:30  A  M 
(15  Samples, Nos.  4SI- 4-65.) 
Slack  Water  -  End  of  Flood  Current. 


Manhattan. 
Pier  10 


Brooklyn. 
Pier  10 


9  =  55-  10^48  A.M. 
(15  Samples,  Nos.  466-480.) 

2  Hours  After  Beginning  of  Ebb  Current. 


12-30-  1:25  P.M. 
(IS  Samples, Nos.  481  -  495.) 

Slack  Water-  End  of  Ebb  Current. 


2^40-  3:28  P.M. 
(15  Samples, Nos  496-510.) 

If  Hours  After  Beginning  of  Flood  Current. 


4--SS-  5:31  P.M 
(l2  Samples, Nos  511-522.) 


6:20-  7>I0  P  M 
(15  Samples,  Nos  523-537.) 


3f  Hours  After  Beginning  of  Flood  Current    5  Hours  After  Beginning  of  Flood  Current 


so' 


100 


Vertical  Scale 


0'  500'  1000' 
i  ....  I  ....  I 


2000' 
 I  


3000' 
_J 


Horizontal  Scale. 


FIG.  51 


Cross-Section  of  the  Mouth  of  the  East  River  from  Pier  10,  Manhattan,  to  Pier  10,  Brook- 
lyn, showing  Percentage  of  Saturation  of  Dissolved  Oxygen  in  Full  Lines  and  Percentage 
of  Sea  Water  in  Broken  Lines,  at  Various  Stages  of  Tide,  July  2,  1913.  The  Total  Number 
of  Samples  included  is  90.    Sampling  Points  are  indicated  by  Small  Circles. 


DISSOLVED  OXYGEN  IN  THE  WATER 

8       9       10      II  A.M.  12       I  P.M.  2  3 


II  A.M.  12 
FIG.  52 

Percentage  of  Saturation  of  Dissolved  Oxygen  in  Heavy  Lines,  and  Percentage  of  Sea  Water  in  Light 
Lines,  in  a  Cross-Section  of  the  Hudson  River  at  Mt.  St.  Vincent,  at  Various  Stages  of  Tide,  July  16, 
1913.  The  Total  Number  of  Samples  included  is  75.  }4The  Results  of  Analysis  are  indicated  by  Small 
Circles,  Triangles  and  Squares. 


718        DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 
7       8       3       10      1 1A.M.  12       IRM.  2       3       4  5 


Q_  '0 


FIG.  52— Continued 


Comparison  of  Curves  of  Data  for  the  Hudson  River  at  Mount  St.  Vincent  in 

1911  and  1913 

A  number  of  points  of  interest  became  apparent  on  comparing  the  foregoing  curves 
with  those  made  from  data  collected  in  the  same  section  in  1911.  The  1911  curves  can 
be  found  in  the  report  of  this  Commission  of  August,  1912,  Part  III,  Chapter  III,  p.  454. 

There  was  a  greater  range  in  the  oxygen  values  in  1913  than  in  1911.  In  1911 
the  oxygen  values  were  usually  larger  at  the  greater  depths,  while  in  1913  the  reverse 
was  generally  the  case.  In  both  years  the  variation  was  greater  and  the  changes  more 
abrupt  at  the  surface  than  at  the  bottom  or  mid-depth. 

In  both  years  there  was  a  marked  rise  of  oxygen  on  the  ebb  current,  at  all  depths, 
probably  showing  that  cleaner  water  came  down  from  the  Upper  Hudson  and  more 
polluted  water  came  up  from  the  City  of  New  York  to  the  point  where  the  oxygen 
determinations  were  made. 


DISSOLVED  OXYGEN  IN  THE  WATER 


719 


New  Jersey. 


Mt. St. Vincent 
New  York 


6-50-8  =  00  A.M. 
(15  Samples.  Nos.  1003-1017.) 

2  Hours  Before  End  of  Flood  Current. 


New  Jersey 


Mt.  St.  Vincent. 
New  York. 


11:4-5-  12:4-0  PH 
(l5.  Samples,  Nos.  1033-1047.) 

2{  Hours  /^fter  Beginning  of  Ebb  Current. 


9:20-  I0: 17  A.M 
(15  Samples. Nos.  1018- I03Z.) 
Slack  Water  -  End  of  Flood  Current. 

New  Jersey. 


KS5-  2  •  50  P.M. 
(15  Samples.  Nos.  1048-1062.) 

4|  Hours  After  Beginning  of  Ebb  Current. 


Mt.  St.  Vincent. 
New  York. 


4-50- S' 40  P.M. 
(IS  Samples, Nos.  1063-1077.) 

Slack  Water- End  of  Ebb  Current. 


O'  50'  I00'  0'  1000'  2000'  3000' 

  i—i  .  ■  ■ — i  » ■  ■  ■  -  ■  i  i 

Vertical  Scale.  Horizontal  Scale. 

FIG.  53 

Cross-Section  of  the  Hudson  River  at  Mt.  St.  Vincent,  showing  Percentage  of  Saturation  of  Dissolved  Oxygen 
in  Full  Lines,  and  Percentage  of  Sea  Water  in  Broken  Lines,  at  Various  Stages  of  Tide,  July  16,  1913.  The 
Total  Number  of  Samples  included  is  76.   Sampling  Points  are  indicated  by  Small  Circles. 


720         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 
.7       8       9       10       11A.M.  12       IRM.  2       3      4       5  6 


FIG.  54 

Percentage  of  Saturation  of  Dissolved  Oxygen  in  Heavy  Lines,  and  Percentage  of  Sea 
Water  in  Light  Lines,  in  a  Cross-Section  of  the  East  River  from  Throgs  Neck  to  Cryders 
Point,  at  Various  Stages  of  Tide,  July  14,  1913.  The  Total  Number  of  Samples  included 
is  90.   The  Results  of  Analysis  are  indicated  by  Small  Circles,  Triangles  and  Squares. 


DISSOLVED  OXYGEN  IN  THE  WATER 


721 


ThrogsNeck  Cryders  Pt/    ThrogsNeck  Cryders  Pt 


ueens 


7:25  -  8'-  25  A.M.  2-35-3'40PM 
(15  Samples, Nos  895-905.)  (15  Samples.  Nos.  940-  954.) 

4i  Hours  Before  End  of  Ebb  Current.  1^  Hours  After  Beginning  of  Flood  Current. 


3:45-10-45  A.M.  4  =  45- 5-35  PM 

(15  Samples,  Nos.  910-  924.)  (15  Samples, Nos.  955-969.) 

2j  Hours  Before  End  of  Ebb  Current.  3£  Hours  After  Beginning  of  Flood  Current. 


12-25 -I -27  P.M. 
(15  Samples,  Nos.  925-939.) 

Slack  Water  -  End  of  Ebb  Current. 


6>I0-  6--S5  P.M. 
(15  Samples, Nos.  970  -  984.) 
Slack  Water  -  End  of  Flood  Current. 


o' 


so' 
I  I 


100' 

_l 


Vertical  Scale. 


0' 

1 1  i  i 


I  i  i 


1000 


2000' 


Horizontal  Scale. 


FIG.  55 


Cross  Section  of  the  East  River  from  Throgs  Neck  to  Willets  Point,  showing  Percentage  of  Saturation  of 
Dissolved  Oxygen  in  Full  Lines,  and  Percentage  of  Sea  Water  in  Broken  Lines,  at  Various  Stages  of  Tide, 
July  14,  1913.  The  Total  Number  of  Samples  included  is  90.  Sampling  Points  are  indicated  by  Small 
Circles. 


722         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


SECTION  IV 

CONSUMPTION  OF  DISSOLVED  OXYGEN  BY  VARIOUS  MIXTURES 
OF  WATER,  SEWAGE  AND  SLUDGE  DURING  INCUBATION 

Most  of  the  experiments  described  in  the  following  pages  were  made  in  order  to  de- 
termine how  rapidly  and  to  what  extent  the  oxygen  dissolved  in  sea  water,  land  water 
and  New  York  harbor  water  would  be  consumed  during  incubation  for  seven  days  at 
temperatures  ranging  from  65°  F.  to  80°  F. 

In  other  cases  sewage  was  added  in  order  to  measure  the  oxygen  consuming  power 
of  the  organic  matter  of  sewage  origin. 

Sources  of  Samples 

The  sea  water  was  collected  off  Sandy  Hook  and  Far  Rockaway,  these  points  being 
selected  in  order  that  the  samples  might  be  free  from  pollution. 

The  harbor  water  was  taken  from  a  number  of  typical  points  located  in  the  East 
river,  Hudson  river  midway  between  Pier  A  and  the  docks  of  the  Central  Railroad  of 
New  Jersey,  in  the  Upper  bay  at  Robbins  Reef,  in  the  Kill  van  Kull  opposite  the 
Sailors  Snug  harbor,  and  at  the  Narrows  midway  between  Forts  Lafayette  and  Wads- 
worth. 

The  samples  were  collected  near  the  surface  and  bottom  on  ebb  and  flood  tides  and 
at  various  seasons  of  the  year. 

The  land  water  samples  were  drawn  from  the  public  water  supply  of  the  City  of 
New  York. 

The  sewage  was  taken  from  Delancey  street  at  the  corner  of  Pitt  street.  This 
location  was  chosen  for  sampling  because  the  sewer  drains  a  characteristic  section  of 
the  thickly  settled  East  Side  of  New  York  and  because  a  weir  constructed  in  the  sewer 
at  this  point  assisted  the  collector  in  getting  representative  samples. 

Ten  samples  of  sea  water,  186  samples  of  harbor  water,  8  samples  of  land  water, 
6  samples  of  sewage  and  one  sample  of  harbor  sludge  were  used  in  these  inves- 
tigations. 

Consumption  op  Dissolved  Oxygen  on  Incubating  Sea  Water 

In  order  to  determine  what  loss  of  oxygen  would  occur  on  incubating  sea  water 
which  was  practically  free  from  organic  matter,  a  sample  of  the  water  was  collected 


CONSUMPTION  OF  OXYGEN  ON  INCUBATION  723 

on  September  3,  1912,  from  the  ocean  off  Far  Rockaway  and  incubated  for  seventeen 
days  at  a  temperature  averaging  70°  F.   The  data  obtained  are  given  in  Table  CXXXI. 

TABLE  CXXXI 

Consumption  of  Dissolved  Oxygen  by  Clean  Sea  Water  Incubated  for  17  Days  at 

Boom  Temperature 


Source  of  Sample 

Date  of 
Collection 

Temp. 
Deg.  C. 

Specific 
Gravity 

Aver.  Temp. 

During 
Incubation 
Deg.  C. 

Dissolved  Oxygen 

C.  C.  per  Litre 

Per 
Cent. 
Lost 

Initial 

After 
Incubation 

Loss 

Ocean,  off  Far  Rockaway  

1912 
Sept.  3 

20.6 

1023 

21.1 

5.60 

5.40 

0.20 

3.6 

The  data  given  in  Table  CXXXI  show  that  the  unpolluted  sea  water  lost  only  a 
trace  of  its  dissolved  oxygen  during  incubation  for  over  two  weeks  at  an  average  tem- 
perature of  70°  F. 


Consumption  of  Dissolved  Oxygen  by  Lower  East  River  Water 

In  order  to  determine  what  loss  of  dissolved  oxygen  would  occur  during  incubation 
in  the  sewage-polluted  water  of  the  Lower  East  river,  four  samples  were  collected  on 
August  21,  1913,  between  Hell  Gate  and  Brooklyn  Bridge  and  incubated  for  nine  days 
at  room  temperature.   The  data  obtained  are  contained  in  Table  CXXXII. 


TABLE  CXXXII 

Consumption  of  Dissolved  Oxygen  in  Harbor  Water  fkom  the  Lower  East  River 
Incubated  for  2,  7  and  9  Days  at  Room  Temperature 


Source  of  Sample 

Date  of 
Collection 

Temp. 
Deg.  C. 

Specific 
Gravity 

Aver.  Temp. 

During 
Incubation 
Deg.  C. 

Dissolved  Oxygen 

C.  C.  per  Litre 

Per 
Cent. 
Lost 

in 
9  ds. 

Initial 

After  Incubation  for 

Loss 

in 
9  ds. 

2  ds. 

7ds. 

9  ds. 

East  River  at 

Hell  Gate  

Queensboro  Bridge. . . 
Williamsburg  Bridge. 
Brooklyn  Bridge  

1913 
Aug.  23 
Aug.  23 
Aug.  23 
Aug.  23 

21.7 
23.9 
23.3 
23.3 

1018.0 
1018.5 
1019.0 
1018.5 

21.7 
21.7 
21.7 
21.7 

5.60 
5.29 
5.45 
5.29 

4.20 
4.74 
4.67 
4.58 

2.90 
3.16 
3.20 
3.48 

2.50 
2.76 
2.30 
2.98 

3.10 
2.53 
3.15 
2.31 

55 
48 
58 
43 

Average  51 


724         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

The  data  given  in  Table  CXXXII  show  that  the  four  samples  of  water  collected 
from  the  East  river  on  August  23,  1913,  lost,  on  an  average,  51  per  cent,  of  their  dis- 
solved oxygen  on  incubation  for  9  days  at  room  temperature. 

Consumption  op  Dissolved  Oxygen  by  Water  prom  Various  Points  in  the  Harbor 

Nine  sets  of  samples,  collected  near  the  surface  and  near  the  bottom  on  flow  and 
ebb  tides,  were  taken  at  various  points  in  the  harbor  during  1912  and  1913  and  tested 
at  once  for  dissolved  oxygen. 

Duplicate  samples  brought  to  the  laboratory  were  incubated  for  7  days  at  room 
temperature  and  then  tested  for  dissolved  oxygen.  The  data  obtained  are  given  in 
Tables  CXXXIII  to  CXXXVII. 

TABLE  CXXXIII 

Dissolved  Oxygen  in  Harbor  Water  Before  and  After  Incubation — East  River  at 


Brooklyn  Bridge,  Mid-stream 


Date 

Surface 

Current 

Date 

Bottom 

Current 

C.  C.  per  Litre  of  Water 

C.  C.  per  Litre  of  Water 

As 
Collected 

After 
Incubation 

Lost 

As 
Collected 

After 
Incubation 

Lost 

1912 
Apr.  3 

June  13 

July  11 

July  24 

1913 
Jan.  9 

Feb.  18 

June  11 

July  25 

Sept.  19 

6.71 
6.71 
3.68 
3.88 
2.60 
2.40 
2.80 
2.50 

6.00 
5.60 
5.60 
5.40 
4.83 
2.49 
2.60 
1.20 
2.30 
2.00 

3.92 
3.47 
2.86 
2.76 
0.80 
0.70 
1.00 
0.60 

4.60 
4.80 
3.10 
2.00 
1.80 
0.00 
0.70 
0.77 
1.58 
0.40 

2.97 
3.24 
0.82 
1.12 
1.80 
1.70 
1.80 
1.90 

1.40 
0.80 
2.50 
3.40 
3.03 
2.49 
1.90 
0.43 
0.72 
1.60 

Flood 

Ebb 
Flood 

Ebb 
Flood 

Ebb 
Flood 

Ebb 

Flood 

Ebb 
Flood 

Ebb 
Flood 

Ebb 
Flood 

Ebb 
Flood 

Ebb 

1912 
Apr.  3 

June  13 

July  11 

July  24 

1913 
Jan.  9 

Feb.  18 

June  11 

July  25 

Sept.  19 

6.71 
6.43 
3.68 
3.88 
2.60 
2.40 
2.80 
2.50 

6.00 
6.60 
5.60 
5.40 
5.08 
2.51 
2.45 
1.35 
1.90 
1.99 

3.78 
3.11 
2.55 
2.86 
0.80 
2.40 
1.20 
0.70 

4.90 
4.60 
3.00 
3.00 
2.83 
0.00 
1.35 
0.33 
1.89 
1.39 

2.79 
3.32 
1.13 
1.02 
1.80 
0.70 
1.60 
1.80 

1.10 
1.00 
2.40 
2.40 
2.25 
2.51 
1.10 
1.02 
0.01 
0.60 

Flood 

Ebb 
Flood 

Ebb 
Flood 

Ebb 
Flood 

Ebb 

Flood 

Ebb 
Flood 

Ebb 
Flood 

Ebb 
Flood 

Ebb 
Flood 

Ebb 

Average 

3.85 

1.99 

1.86 

Average 

3.83 

2.26 

1.58 

CONSUMPTION  OF  OXYGEN  ON  INCUBATION  725 
TABLE  CXXXIV 


Dissolved  Oxygen  in  Harbor  Water  Before  and  After  Incubation — Hudson  River, 

Mid-stream,  Pier  A 


Date 

Surface 

Current 

Date 

Bottom 

Current 

C.  C.  per  Litre  of  Water 

C.  C.  per  Litre  of  Water 

As 
Collected 

After 
Incubation 

Lost 

As 
Collected 

After 
Incubation 

Lost 

1912 
Apr.  3 

June  13 

T.  .1..  11 

July  11 

July  24 

1913 
Jan.  9 

Feb.  18 

June  11 

July  25 

Sept.  19 

7.43 
7.57 
4.19 
4.49 
3.00 
2.90 
3.70 
3.10 

6.20 
5.70 
5.80 
5.80 
4.11 
3.77 
2.88 
2.70 
2.70 
3.20 

4.46 
3.89 
3.16 
3.16 
0.80 
1.10 
2.00 
2.00 

5.00 
4.40 
4.00 
4.00 
2.08 
1.85 
1.38 
1.33 
0.66 
2.79 

2.97 
3.68 
1.03 
1.33 
2.20 
1.80 
1.70 
1.10 

1.20 
1.30 
1.80 
1.80 
2.03 
1.92 
1.50 
1.44 
2.04 
0.41 

Flood 

Ebb 
Flood 

Ebb 
r  looa 

Ebb 
Flood 

Ebb 

Flood 

Ebb 
Flood 

Ebb 
Flood 

Ebb 
Flood 

Ebb 
Flood 

Ebb 

1912 
Apr.  3 

June  13 

T.,l„  11 

July  11 

July  24 

1913 
Jan.  9 

Feb.  18 

June  11 

July  25 

Sept.  19 

6.80 
7.57 
4.19 
4.39 

2.80 
3.17 
3.00 

6.20 
5.70 
5.90 
5.80 
4.72 
3.97 
2.51 
2.54 
2.80 
3.51 

4.32 
3.78 
2.86 
3.27 

0.60 
2.10 
2.10 

5.10 
5.10 
4.00 
3.40 
2.09 
1.80 
1.05 
0.49 
1.31 
1.60 

2.48 
3.79 
1.33 
1.12 

1.20 
1.60 
0.90 

1.10 
0.60 
1.90 
2.40 
2.63 
2.17 
1.46 
1.05 
1.49 
1.91 

Flood 

Ebb 
Flood 

Ebb 
r  looa 

Ebb 
Flood 

Ebb 

Flood 

Ebb 
Flood 

Ebb 
Flood 

Ebb 
Flood 

Ebb 
Flood 

Ebb 

Average 

4.35 

2.65 

1.74 

Average 

4.44 

2.64 

1.71 

TABLE  CXXXV 

Dissolved  Oxygen  in  Harbor  Water  Before  and  After  Incubation — Bobbins  Reef, 

Near  Bell  Buoy 


Date 

Surface 

Current 

Date 

Bottom 

Current 

C.  C.  per  Litre  of  Water 

C.  C.  per  Litre  of  Water 

Aa 
Collected 

After 
Incubation 

Lost 

As 
Collected 

After 
Incubation 

Lost 

1912 
Apr.  3 

June  13 

July  11 

July  24 

1913 
Jan.  9 

Feb.  18 

June  11 

July  25 

Sept.  19 

7.28 
7.28 
4.29 
4.19 
3.50 
3.00 
3.60 
2.90 

6.30 
6.00 
6.20 
5.90 
5.26 
4.37 
3.80 
2.18 
4.00 
3.60 

4.17 

3.33 
3.16 
3.37 
1.00 
0.70 
2.60 
2.00 

4.90 
4.80 
4.00 
3.30 
2.63 
1.88 
2.37 
1.65 
3.22 
3.41 

3.11 

3.95 
1.13 
0.82 
2.50 
2.30 
1.00 
0.90 

1.40 
1.20 
2.20 
2.60 
2.63 
2.49 
1.43 
0.45 
0.78 
0.19 

Flood 

Ebb 
Flood 

Ebb 
Flood 

Ebb 
Flood 

Ebb 

Flood 

Ebb 
Flood 

Ebb 
Flood 

Ebb 
Flood 

Ebb 
Flood 

Ebb 

1912 
Apr.  3 

June  13 

July  11 

July  24 

1913 
Jan.  9 

Feb.  18 

June  11 

July  25 

Sept.  19 

7.00 

6.86 
4.29 
4.19 
3.50 
3.10 
3.70 
2.90 

5.40 
6.00 
6.20 
6.00 
5.83 
5.58 
4.35 
2.86 
4.18 
4.10 

4.60 
3.24 
3.27 
3.27 
1.00 
0.80 
2.60 
2.20 

5.30 
5.00 
4.00 
3.40 
3.94 
1.25 
2.76 
1.25 
2.80 
3.97 

2.40 
3.62 
1.02 
0.92 
2.50 
2.30 
1.10 
0.70 

1.10 
1.00 
2.20 
2.60 
1.89 
4.23 
1.59 
1.61 
0.38 
0.13 

Flood 

Ebb 
Flood 

Ebb 
Flood 

Ebb 
Flood 

Ebb 

Flood 

Ebb 
Flood 

Ebb 
Flood 

Ebb 
Flood 

Ebb 
Flood 

Ebb 

Average 

4.64 

2.92 

1.73 

Average 

4.78 

3.03 

1.68 

726 


DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


TABLE  CXXXVI 

Dissolved  Oxygen  in  Harbor  Water  Before  and  After  Incubation — Kill  Van 


Kull,  Mid-stream,  Sailors  Snug  Harbor 


Surface 

Bottom 

Date 

C.  C.  per  Litre  of  Water 

Current 

Date 

C.  C.  Der  Litre  of  Water 

Current 

As 

After 

As 

After 

Collected 

Incubation 

Lost 

Collected 

Incubation 

Lost 

1912 

1912 

Apr.  3 

7.00 

4 

44 

2 

56 

Flood 

Apr.  3 

6 

86 

4 

60 

2 

26 

Flood 

7.28 

4 

31 

2 

97 

Ebb 

7 

00 

4 

06 

2 

94 

Ebb 

June  13 

4.39 

2 

96 

1 

43 

Flood 

June  13 

4 

39 

3 

06 

1 

33 

Flood 

4.29 

3 

27 

1 

02 

T?KK 
itiDD 

4 

29 

3 

37 

0 

92 

H/DD 

July  11 

3.20 

1 

00 

2 

20 

Flood 

July  11 

3 

20 

0 

90 

2 

30 

Flood 

3.10 

0 

80 

2 

30 

Ebb 

3 

10 

0 

80 

2 

30 

Ebb 

July  24 

3.80 

2 

50 

1 

30 

Flood 

July  24 

3 

80 

2 

60 

1 

20 

Flood 

3.40 

2 

60 

0 

80 

Ebb 

3 

30 

2 

60 

0 

70 

Ebb 

1913 

1913 

Jan.  9 

6.10 

4 

90 

1 

20 

Flood 

Jan.  9 

6 

20 

4 

60 

1 

60 

Flood 

6.00 

4 

60 

1 

40 

Ebb 

6 

00 

5 

00 

1 

00 

Ebb 

Feb.  18 

6.20 

3 

60 

2 

60 

Flood 

Feb.  18 

6 

30 

4 

20 

2 

10 

Flood 

5.80 

3 

40 

2 

40 

Ebb 

5 

80 

3 

00 

2 

80 

Ebb 

June  11 

4.39 

2 

37 

1 

92 

Flood 

June  11 

3 

92 

2 

33 

1 

59 

Flood 

4.61 

2 

92 

1 

69 

Ebb 

4 

33 

3 

56 

0 

77 

Ebb 

July  25 

3.60 

1 

30 

2 

30 

Flood 

July  25 

3 

25 

1 

02 

2 

23 

Flood 

2.80 

1 

18 

1 

62 

Ebb 

3 

65 

2 

18 

1 

47 

Ebb 

Sept.  19 

2.70 

2 

09 

0 

61 

Flood 

Sept.  19 

3 

12 

1 

42 

1 

70 

Flood 

3.10 

1 

30 

1 

80 

Ebb 

3 

50 

1 

69 

1 

81 

Ebb 

Average 

4.52 

2.75 

1 

79 

Average 

4.56 

2.83 

1 

72 

TABLE  CXXXVII 

Dissolved  Oxygen  in  Harbor  Water  Before  and  After  Incubation — Narrows,  Mid- 
stream, Between  Forts  Lafayette  and  Wadsworth 


Date 

Surface 

Current 

Date 

Bottom 

Current 

C.  C.  per  Litre  of  Water 

C.  C.  per  Litre  of  Water 

As 
Collected 

After 
Incubation 

Lost 

As 
Collected 

After 
Incubation 

Lost 

1912 
Apr.  3 

June  13 

July  11 

July  24 

1913 
Jan.  9 

Feb.  18 

June  11 

July  25 

Sept.  19 

7.71 
7.43 
4.80 
4.29 
3.90 
3.20 
3.90 
3.40 

6.80 
6.10 
6.60 
6.00 
4.11 
5.66 
3.10 
4.10 
3.40 
4.60 

4.86 
4.17 
3.58 
3.47 
1.80 
1.00 
2.40 
2.20 

5.10 
5.10 
4.80 
3.80 
2.79 
3.36 
2.70 
2.67 
2.09 
4.57 

2.85 
3.26 
1.22 
0.82 
2.10 
2.20 
1.50 
1.20 

1.70 
1.00 
1.80 
2.20 
1.32 
2.30 
0.40 
1.43 
1.31 
.03 

Flood 

Ebb 
Flood 

Ebb 
Flood 

Ebb 
Flood 

Ebb 

Flood 

Ebb 
Flood 

Ebb 
Flood 

Ebb 
Flood 

Ebb 
Flood 

Ebb 

1912 
Apr.  3 

June  13 

July  11 

July  24 

1913 
Jan.  9 

Feb.  18 

June  11 

July  25 

Sept.  19 

7.57 
7.14 
4.90 
4.39 
4.00 
3.30 
4.00 
3.40 

6.80 
6.10 
6.70 
6.10 
4.15 
6.07 
4.05 
5.25 
3.60 
5.12 

4.87 
4.06 
3.68 
3.57 
1.80 
1.00 
2.60 
2.40 

5.40 
5.00 
4.80 
4.00 
3.03 
3.26 
2.86 
3.71 
2.53 
4.13 

2.70 
3.08 
1.22 
0.82 
2.20 
2.20 
1.40 
1.00 

1.40 
1.10 
1.90 
2.20 
1.12 
2.81 
2.19 
1.54 
1.07 
0.99 

Flood 

Ebb 
Flood 

Ebb 
Flood 

Ebb 
Flood 

Ebb 

Flood 

Ebb 
Flood 

Ebb 
Flood 

Ebb 
Flood 

Ebb 
Flood 

Ebb 

Average 

4.95 

3.37 

1.59 

Average 

5.15 

3.48 

1.72 

CONSUMPTION  OF  OXYGEN  ON  INCUBATION  727 

Dissolved  Oxygen  in  Harbor  Water  in  Cold  and  in  Warm  Weather 

Inspection  of  the  records  given  in  Tables  CXXXIII  to  CXXXVII  shows  that  the 
amount  of  oxygen  dissolved  in  the  harbor  waters  was  much  greater  in  winter  than  in 
summer.  The  figures  given  in  the  tables  have  been  summarized  for  the  purpose  of  illus- 
trating this  fact  and  the  data  are  given  in  Table  CXXXVIII. 

TABLE  CXXXVIII 


Dissolved  Oxygen  in  Harbor  Water  in  Cold  and  in  Warm  Weather 


C.  C.  per  Litre 

Source  of  Samples 

Jan.,  Feb.,  April 

June,  July,  Sept. 

5.81 

2.77 

6.37 

3.40 

6.79 

3.87 

KiU  van  KuU  

6.37 

3.55 

6.59 

4.19 

Total  

31.93 

17.78 

6.39 

3.56 

The  data  given  in  Table  CXXXVIII  show  that  the  harbor  water  contained  2.83  c.c. 
more  dissolved  oxygen  on  the  average  in  winter  than  in  summer.  This  may  have  been 
due  partly  to  the  fact  that  cold  water  is  capable  of  holding  more  oxygen  than  warm 
water.  For  instance,  harbor  water  saturated  with  dissolved  oxygen  at  40°  F.  contains 
about  7.8  c.c,  whereas  harbor  water  saturated  with  dissolved  oxygen  at  72°  F.  contains 
only  5.4  c.c. 

The  differences  in  volume  of  oxygen  dissolved  in  samples  of  harbor  water  collected 
in  winter  and  summer  may  have  been  due  partly  to  the  fact  that  bacterial  fermentation, 
upon  which  the  decomposition  of  the  organic  matter  depends,  proceeds  more  rapidly 
in  warm  weather,  and  for  that  reason  the  oxygen  is  withdrawn  from  the  water  more 
rapidly. 

Sewage,  however,  flows  into  the  harbor  at  all  seasons  of  the  year  and  it  is  impor- 
tant to  know  whether,  if  digested,  it  will  consume  equal  volumes  of  oxygen  at  all  sea- 
sons. Data  upon  this  point  can  be  obtained  by  adding  to  the  oxygen  consumed  by 
digestion  in  the  river  the  dissolved  oxygen  consumed  during  incubation  at  room  tem- 
perature. 

The  records  of  the  volumes  of  oxygen  dissolved  in  the  3G  samples  of  harbor  water, 
before  and  after  incubation,  which  are  printed  in  Tables  CXXXIII  to  CXXXVII, 
have  been  averaged  and  are  printed  in  Table  CXXXIX,  together  with  figures  for  the 
saturation,  etc.,  in  order  to  bring  out  the  desired  information. 


728         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

TABLE  CXXXIX 
Volume  of  Dissolved  Oxygen  Consumed  During  Digestion  of  Sewage 


Period 

Jan.,  Feb.,  April 

June,  July,  Sept. 

Temperature  

40°  F. 

70°  F. 

70 

70 

Dissolved  Oxygen  Required  for  Saturation  

7.70  c.c. 

5  .50  c.c. 

Found  by  Analysis  at  Time  of  Collection  

6.39 

3.56 

Lost  by  Digestion  in  Harbor  

1.31  c.c. 

1.94  c.c. 

Lost  by  Incubation  for  7  Days  at  70°  F  

2.18  c.c. 

1.48  c.c. 

Total  Loss  During  Digestion  

3.49  c.c. 

3.42  c.c. 

The  actual  volumes  of  oxygen  consumed  in  the  digestion  of  sewage  in  the  harbor 
vary  with  changes  of  temperature  and  also  with  the  volume  absorbed  by  water  from 
the  air. 

Data  given  elsewhere  in  reports  of  the  Commission  show  that  the  rate  at 
which  waters  absorb  oxygen  from  the  atmosphere  vary  with  the  amounts  of 
oxygen  which  the  waters  contain  already,  and  also  with  temperature  and  pressure  ac- 
cording to  the  physical  laws  which  govern  volumes  of  gases.  But  this  latter  factor, 
together  with  variations  produced  by  such  physical  agents  as  tidal  currents,  winds, 
moving  ships,  etc.,  may  be  left  out  of  the  present  discussion  because  the  actual  effects 
produced  are  unknown  and  operate  at  all  seasons  of  the  year. 

The  data  given  in  Table  CXXXIX  show  that  the  volume  of  oxygen  which  the  or- 
ganic matter  carried  by  harbor  water  will  consume  during  digestion  in  cold  weather  is 
3.49  c.c.  per  litre  and  in  warm  weather  3.42  c.c.  Roughly  speaking  then,  the  volume 
of  dissolved  oxygen  required  for  the  digestion  of  sewage  in  the  harbor  water  is  approxi- 
mately the  same  at  all  seasons  of  the  year. 

The  data  given  in  Tables  CXXXIII  to  CXXXVII  prove  that  the  volumes  of  dis- 
solved oxygen  consumed  by  harbor  waters  during  various  seasons  of  the  year  vary  with 
the  locality  from  which  the  samples  are  taken.  This  fact  is  brought  out  in  the  follow- 
ing table: 


TABLE  CXL 

•Volumes  and  Percentages  of  Dissolved  Oxygen  Contained  by  Harbor  Water 

Before  and  After  Incubation 


Dissolved  Oxygen 

Source  of  Sample 

C.  C.  per  Litre  Present 

Per  Cent.  Present 

Before 

After 

Loss 

Before 

After 

Loss 

Incubation 

Incubation 

Incubation 

Incubation 

East  river  at  Brooklyn  Bridge  

3.84 

2.12 

1.72 

100 

55.2 

44.8 

Hudson  river,  off  Pier  A  

4.39 

2.65 

1.75 

100 

60.3 

39.7 

Robbins  Reef,  near  Bell  buoy  

4.71 

2.98 

1.72 

100 

63.2 

36.8 

Kill  van  Kull  at  Sailors  Snug  Harbor  

4.55 

2.79 

1.75 

100 

61.4 

38.6 

Narrows,  between  Forta  

5.04 

3.42 

1.62 

100 

67.3 

32.7 

•Averages  of  39  sets  of  determinations. 


CONSUMPTION  OP  OXYGEN  ON  INCUBATION  729 

The  data  given  in  Table  CXL  show  that  the  samples  of  harbor  water  from  all 
sources  lost  approximately  equal  volumes  of  dissolved  oxygen  during  incubation.  The 
samples  from  the  East  river,  however,  lost  a  larger  percentage  of  the  oxygen  which 
they  originally  contained  than  samples  from  the  Narrows.  This  fact  indicates  that 
the  organic  matter  in  the  East  river  water  was  more  unstable  than  that  in  the  harbor 
water  at  the  Narrows. 

Dissolved  Oxygen  on  Ebb  and  Flood  Tides 

The  data  in  Tables  CXXXIII  to  CXXXVII  have  been  arranged  with  reference  to 
the  volumes  of  dissolved  oxygen  contained  by  ebb  and  flood  tides.  The  data  are  given 
in  Table  CXLI. 

TABLE  CXLI 

Dissolved  Oxygen  Contained  by  Harbor  Waters  on  Ebb  and  Flood  Tides 


Average  Number  of  C.  C.  per  Litre 


East  River, 
Brooklyn  Bridge 

Hudson  River, 
Pier  A 

Robbins  Reef, 
Bell  Buoy 

Kill  van  Kull, 
Sailors  Snug  Harbor 

Narrows, 
between  Forts 

Ebb  

3.57 
4.11 

4.36 
4.24 

4.50 
4.93 

4.47 
4.62 

5.09 
5.00 

Flood  

The  data  given  in  Table  CXLI  show  that  the  amount  of  dissolved  oxygen  con- 
tained by  the  harbor  water  did  not  differ  much  on  the  ebb  and  flood  tides. 

Dissolved  Oxygen  in  Surface  and  Bottom  Samples 

The  data  contained  in  Tables  CXXXIII  to  CXXXVII  have  been  arranged  with 
regard  to  the  location  of  the  samples  for  the  purpose  of  comparing  the  oxygen  con- 
tained by  water  lying  near  the  surface  with  that  at  the  bottom.  The  data  are  given  in 
Table  CXLII. 


TABLE  CXLII 

Dissolved  Oxygen  Contained  by  Harbor  Water  Collected  About  One  Foot  Below 
the  Surface  and  One  Foot  Above  the  Bottom 


Average  Number  of  C.  C.  per  Litre 

East  River, 
Brooklyn  Bridge 

Hudson  River, 
,  Pier  A 

Robbins  Reef, 
Bell  Buoy 

Kill  van  Kull, 
Sailors  Snug  Harbor 

Narrows, 
between  Forts 

Top  

3.65 
3.82 

4.40 
4.20 

4.64 
4.78 

4.57 
4.51 

4.95 
5.15 

730         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

The  data  given  in  this  table  show  that  there  was  not  much  difference  between  the 
amounts  of  oxygen  contained  by  the  surface  and  bottom  samples. 

Consumption  op  Oxygen  in  Mixtures  op  Sewage  and  Aerated  Water  During 

Incubation 

As  the  sewage  uses  up  part  of  the  oxygen  contained  by  the  water,  it  is  important  to 
know  whether  the  solid  or  liquid  portion  of  the  organic  matter  consumes  the  greater 
volume  of  oxygen.  To  get  information  on  this  point  mixtures  of  aerated  harbor,  land 
and  sea  water  were  made  with  various  percentages  of  raw,  settled  and  filtered  sewage. 
The  volumes  of  dissolved  oxygen  contained  by  the  mixtures  were  determined  at  the 
time  when  the  mixtures  were  made  and  after  incubation  for  various  periods. 

Consumption  op  Dissolved  Oxygen  in  Mixtures  op  Harbor  Water  with  20  Per  Cent, 
op  Raw  and  with  20  Per  Cent,  op  Settled  Sewage 

Sewage  collected  from  the  Delancey  street  sewer  was  carried  to  the  laboratory, 
shaken  thoroughly  and  divided  into  two  parts.  One  portion  after  thorough  agitation 
was  mixed  with  aerated  harbor  water  drawn  from  the  East  river  at  Pier  4  and  the  other 
portion  was  allowed  to  settle  for  two  hours  to  free  it  from  coarser  particles  of  sus- 
pended matter.  The  supernatant  liquor,  siphoned  from  the  upper  portion  of  the  sample, 
was  shaken  thoroughly  and  mixed  with  aerated  harbor  water.  In  each  case  20  per  cent, 
of  sewage  liquor  was  added  to  80  per  cent,  of  harbor  water.  Tests  were  made  for  dis- 
solved oxygen  at  intervals.  The  data  are  given  in  Tables  CXLIII,  CXLIV  and  CXLV. 

TABLE  CXLIII 

Consumption  op  Dissolved  Oxygen  on  Incubating  Mixtures  Containing  20  Per 
Cent.  Raw  Sewage  and  20  Per  Cent.  Settled  Sewage  with  Aerated  Harbor 
Water. 


Date  of 
Collection 

Source  of 

Aver. 
Temp. 
Deg.  F. 

Dissolved  Oxygen 

Sewage 

Harbor  Water 

After 
Standing 

Raw  Sewage 

Settled  Sewage 

C.  C. 
per 
Litre 

Per 
Cent. 

of 
Initial 

Per 
Cent. 
Satura- 
tion 

C.  C. 
per 
Litre 

Per 
Cent. 

of 
Initial 

Per 
Cent. 
Satura- 
tion 

1913 

Initial 

4.52 

100 

75 

4.10 

100 

70 

2  hours 

2.80 

59 

49 

4.05 

98 

70 

Oct.  17 

Delancey  street,  1 

East  river,  Pier  \ 

4  hours 

1.48 

33 

25 

1.48 

34 

25 

corner  Pitt. . .  / 

No.  4  J 

70  • 

5  hours 

0.48 

11 

8 

0.98 

21 

17 

6  hours 

0.19 

4 

3 

0.26 

6 

5 

7  hours 

0.04 

0.8 

0.7 

.00 

0 

0 

CONSUMPTION  OF  OXYGEN  ON  INCUBATION  731 
TABLE  CXLIV 

Consumption  of  Dissolved  Oxygen  on  Incubating  Mixtures  op  20  Per  Cent.  Raw 


Sewage  and  20  Per  Cent.  Settled  Sewage  with  Aerated  Harbor  Water 


Source  of 

Dissolved  Oxygen 

Date  of 

Aver. 
Temp. 

Raw  Sewage 

Settled  Sewage 

Collection 

Sewage 

Harbor  Water 

Deg.  F. 

After 
Standing 

C.  C. 
per 
Litre 

Per 
Cent. 

of 
Initial 

Per 
Cent. 
Satura- 
tion 

C.  C. 
per 
Litre 

Per 
Cent. 

of 
Initial 

Per 

Cent. 
Satura- 
tion 

1913 
Oct.  21 

Delancey  street,  1 
corner  Pitt. . .  / 

East  river,  Pier 
No.  4  ' 

60 
61 
63 
63 
63 
61 
60 

Initial 
2  hours 
4  hours 
6  hours 
8  hours 
10  hours 
12  hours 

6.41 
5.28 
4.38 
3.73 
2.09 
0.18 
0.00 

100 
80 
66 
58 
32 
2 
0 

101 

82 
71 
60 
33 

3.2 

0 

6.51 
6.51 
5.23 
4.82 
3.45 
1.12 

100 
100 
80 
74 
53 
17 

103 
103 
85 
78 
55 
16 

TABLE  CXLV 

Consumption  of  Dissolved  Oxygen  on  Incubating  Mixtures  of  20  Per  Cent.  Raw 
Sewage  and  20  Per  Cent.  Settled  Sewage  with  Aerated  Harbor  Water 


Source  of 

Dissolved  Oxygen 

Date  of 

Aver. 

Raw  Sewage 

Settled  Sewage 

Collection 

Sewage 

Harbor  Water 

Temp. 
Deg.  F. 

After 
Standing 

C.  C. 
per 
Litre 

Per 
Cent. 

of 
Initial 

Per 

Cent. 
Satura- 
tion 

C.  C. 
per 
Litre 

Per 
Cent. 

of 
Initial 

Per 
Cent. 
Satura- 
tion 

1913 
Oct.  23 

Delancey  .near  Pitt 

East  river,  Pier  \ 
No.  4  J 

61 

Initial 
2  hours 
4  hours 
6  hours 
12  hours 

5.68 
5.40 
4.17 
3.28 
.05 

100 

92 
76 
57 
0.7 

90 
75 
70 
54 
0.6 

5.93 
5.95 
4.23 
2.95 
0.51 

100 
100 
71 
49 
10 

95 
95 
68 
48 
8 

The  data  given  in  Tables  CXLIII,  CXLIV  and  CXLV  show  that  the  raw  and  set- 
tled sewage  consumed  all  the  oxygen  in  the  harbor  water  within  12  hours,  and  that  the 
raw  sewage  used  up  the  dissolved  oxygen  more  rapidly  than  did  settled  sewage  during 
the  first  two  hours. 

Consumption  of  Oxygen  in  Mixtures  of  Harbor  Water  with  5  Per  Cent,  of  Raw 

and  5  Per  Cent,  of  Settled  Sewage 

The  large  amount  of  organic  matter  introduced  when  20  per  cent,  of  sewage  was 
added  to  the  harbor  water  exhausted  the  oxygen  rapidly.  As  the  proportion  of  sewage 


732         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

to  harbor  water  might  not  be  as  great  as  20  per  cent,  in  actual  practice,  tests  were 
made  using  only  5  per  cent,  of  sewage.  The  data  obtained  are  given  in  Tables  CXLVI 
and  CXLVII. 

TABLE  CXLVI 


Consumption  op  Dissolved  Oxygen  on  Incubating  Mixtures  op  5  Per  Cent.  Raw 
Sewage  and  5  Per  Cent.  Settled  Sewage  with  Aerated  Harbor  Water 


Date  of 
Collection 

Source  of 

Aver. 
Temp. 
Deg.  F. 

Dissolved  Oxygen 

Sewage 

Harbor  Water 

After 
Standing 

Raw  Sewage 

Settled  Sewage 

C.  C. 
per 
Litre 

Per 
Cent. 

of 
Initial 

Per 
Cent. 
Satura- 
tion 

C.  C. 
per 
Litre 

Per 
Cent. 

of 
Initial 

Per 

Cent. 
Satura- 
tion 

1913 
Oct.  28 

Delancey  street,  1 
corner  of  Pitt.  J 

East  river,  Pier  \ 
No.  4  / 

68  | 

Initial 
6  hours 
21  hours 
24  hours 

6.42 
6.05 
0.22 
0.05 

100 
94 
3 
0 

109 
102 
3 
0 

6.21 
6.26 
0.26 
0.00 

100 
101 
4 
0 

106 
107 
4 
0 

TABLE  CXLVII 


Consumption  of  Dissolved  Oxygen  on  Incubating  Mixtures  of  5  Per  Cent.  Raw 
Sewage  and  5  Per  Cent.  Settled  Sewage  with  Aerated  Harbor  Water 


Date  of 
Collection 

Source  of 

Aver. 
Temp. 
Deg.  F. 

Dissolved  Oxygen 

Sewage 

Harbor  Water 

After 
Standing 

Raw  Sewage 

Settled  Sewage 

C.  C. 
per 
Litre 

Per 
Cent. 

of 
Initial 

Per 

Cent. 
Satura- 
tion 

C.  C. 
per 
Litre 

Per 
Cent. 

of 
Initial 

Per 

Cent. 
Satura- 
tion 

1913 

Initial 

5.82 

100 

92 

6.48 

100 

107 

6  hours 

4.56 

78 

75 

5.24 

80 

85 

Oct.  30 

Delancey  street,  1 

East  river,  Pier  \ 

12  hours 

1.63 

28 

27 

3.17 

48 

51 

corner  of  Pitt.  / 

No.  4  J 

70  ■■ 

21  hours 

0.00 

0 

0 

1.49 

22 

24 

24  hours 

1.18 

18 

19 

28  hours 

0.57 

9 

9 

The  data  given  in  Tables  CXLVI  and  CXLVII  show  that  in  the  presence  of  5  per 
cent,  of  raw  sewage  the  organic  matter  consumed  all  the  oxygen  in  the  harbor  water  in 
21  hours  and  that  5  per  cent,  of  settled  sewage  consumed  all  the  oxygen  in  about  28  hours. 


CONSUMPTION  OP  OXYGEN  ON  INCUBATION 


733 


Consumption  in  Mixtures  of  Land  Water  with  Various  Percentages  of  Filtered 

Sewage 

Sewage  collected  from  the  Delancey  street  sewer  was  carried  to  the  Laboratory  and 
passed  through  coarse  filter  paper  to  remove  all  of  the  suspended  matter.  Various 
quantities  of  this  filtered  sewage  were  then  mixed  with  aerated  land  water  and  tests 
made  at  intervals  for  dissolved  oxygen.  The  data  obtained  are  given  in  Table  CXLVIII. 

TABLE  CXLVIII 


Consumption  of  Dissolved  Oxygen  on  Incubating  Mixtures  of  20  Per  Cent.,  10  Per 
Cent.,  5  Per  Cent,  and  3  Per  Cent,  of  Filtered  Sewtage  with  Aerated  Land 
Water. 


Date  of 
Collection 

Composition  of  Sample 

Aver. 
Temp. 
Deg.  F. 

Dissolved  Oxygen  C.  C.  per  Litre 

Initial 

After  Standing 

1913 
Jan.  23 
Jan.  23 
Jan.  23 
Jan.  24 

Land  Water,  plus: 

20  per  cent.  Filtered  Sewage  

10  per  cent.  Filtered  Sewage  

5  per  cent.  Filtered  Sewage  

3  per  cent.  Filtered  Sewage  

80 
80 
80 
80 

4.60 
5.10 

6.20 
5.80 

24  hours 
0.10 
0.30 
2.60 
4.80 

5  days 
0.00 
0.00 
0.50 
1.70 

The  data  given  in  Table  CXLVIII  show  that  in  the  presence  of  10  per  cent,  or  more 
of  filtered  sewage  practically  all  the  oxygen  disappeared  in  24  hours.  On  the  other 
hand,  land  water  mixed  with  5  per  cent,  of  filtered  sewage  lost  only  60  per  cent,  and 
3  per  cent,  of  filtered  sewage  lost  only  17  per  cent,  of  dissolved  oxygen  in  24  hours.  Al- 
most all  the  oxygen  disappeared  from  the  5  per  cent,  mixture  in  five  days,  but  the  3  per 
cent,  mixture  still  contained  about  30  per  cent,  of  oxygen  at  the  end  of  this  period. 

Consumption  in  Mixtures  of  Sea  Water  with  Various  Percentages  of  Filtered 

Sewage 

Samples  of  the  filtered  sewage  described  in  the  preceding  tables  were  mixed  in 
various  percentages  with  aerated  sea  water,  collected  off  Sandy  Hook,  and  tested  for 
dissolved  oxygen  after  different  periods  of  incubation.  The  data  obtained  are  given  in 
Table  CXLIX. 

TABLE  CXLIX 


Consumption  of  Dissolved  Oxygen  on  Incubating  Mixtures  of  50  Per  Cent.,  20  Per 
Cent.,  10  Per  Cent.,  5  Per  Cent,  and  3  Per  Cent,  of  Filtered  Sewage  with 
Aerated  Sea  Water. 


Date  of 
Collection 

Composition  of  Sample 

Aver. 
Temp! 
Deg.  F. 

Dissolved  Oxygen  C.  C.  per  Litre 

Initial 

After  Standing 

1913 
Jan.  23 
Jan.  23 
Jan.  23 
Jan.  23 
Jan.  23 

Sea  Water,  plus 

20  per  cent.  Filtered  Sewage  

10  per  cent.  Filtered  Sewage  

5  per  cent.  Filtered  Sewage  

3  per  cent.  Filtered  Sewage  

80 
80 
80 
80 
80 

4.36 
4.00 
5.00 
5.80 
5.50 

24  hours 
0.00 
0.10 
0.50 
2.40 
4.50 

5  days 
0.00 
0.00 
0.00 
0.60 
0.60 

734         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

The  data  given  in  Table  CXLIX  show  that  practically  all  the  oxygen  disappeared 
within  24  hours  in  mixtures  of  10  per  cent,  or  more  of  filtered  sewage  and  aerated  sea 
water.  A  mixture  of  sea  water  with  5  per  cent  of  filtered  sewage  lost  60  per  cent.,  and 
a  mixture  of  sea  water  with  3  per  cent,  of  filtered  sewage  lost  18  per  cent,  of  dissolved 
oxygen  in  24  hours.   By  the  end  of  5  days  the  oxygen  had  nearly  disappeared. 

Consumption  in  Mixtures  of  Filtered  Sewage  and  Water  Containing  Various 

Initial  Percentages  op  Oxygen 

Owing  to  the  fact  that  oxygen  exists  in  varying  amounts  in  the  harbor  water,  mix- 
tures of  land  water,  land  and  sea  water,  and  sea  water  with  filtered  sewage  were  charged 
by  aeration  with  oxygen  to  different  percentages  of  saturation. 

The  samples  were  incubated  at  about  80°  F.  and  tested  for  oxygen  at  the  start, 
after  24  hours  and  after  5  days.  The  data  obtained  are  given  in  Tables  CL,  CLI  and 
CLII. 

TABLE  CL 


Consumption  op  Oxygen  on  Incubating  Mixtures  op  20  Per  Cent.,  10  Per  Cent.,  5 
Per  Cent,  and  3  Per  Cent,  op  Filtered  Sewage  with  Aerated  Land  Water  Con- 
taining Various  Amounts  op  Oxygen. 


Dissolved  Oxygen 

Aver. 

C.  C.  per  Litre 

Composition  of  Sample 

Temp. 

Deg.  F. 

Initial 

After  Standing  for 

Land  Water,  plus: 

24  hours 

5  days 

[  4.60 

0.10 

0.00 

80 

1.60 

0.10 

0.00 

0.40 

0.00 

0.00 

r  5.10 

0.30 

0.00 

80 

2.00 

0.00 

0.00 

0.80 

0.00 

0.00 

r  6.20 

2.60 

0.50 

80 

4.90 

0.70 

0.00 

1.90 

0.00 

0.00 

'  6.80 

4.80 

1.70 

80 

3.90 

2.40 

0.30 

0.90 

0.60 

0.00 

CONSUMPTION  OF  OXYGEN  ON  INCUBATION 


735 


TABLE  CLI 

Consumption  op  Oxygen  on  Incubating  10  Per  Cent,  op  Filtered  Sewage  Added  to 
a  Mixture  of  60  Per  Cent.  Sea  Water  with  40  Per  Cent,  of  Land  Water  Con- 


taining Various  Amounts  of  Dissolved  Oxygen. 


Composition  of  Sample 

Aver. 
Temp. 
Deg.  F. 

Dissolved  Oxygen 
C.  C.  per  Litre 

Initial 

After  Standing  for 

60  per  cent.  Sea    Water,  1  . 
40  per  cent.  Land  Water,  J  p 

6  hours 

24  hours 

f  5.50 

4.50 

0.60 

10  per  cent.  Filtered  Sewage  

80 

3.20 

2.70 

0.20 

{  1.50 

0.90 

0.20 

TABLE  CLII 

Consumption  of  Oxygen  on  Incubating  Mixtures  of  20  Per  Cent.,  10  Per  Cent.,  5 
Per  Cent,  and  3  Per  Cent,  of  Filtered  Sewage  with  Aerated  Sea  Water  Con- 
taining Various  Amounts  of  Oxygen. 


Dissolved  Oxygen 

Aver. 

C.  C. 

per  Litre 

Composition  of  Sample 

Temp. 

Deg.  F. 

Initial 

After  Standing  for 

Sea  Water,  plus: 

24  hours 

4.00 

0.10 

80 

2.40 

0.00 

0.60 

0.00 

5.00 

0.50 

80 

3.00 

0.40 

1.60 

0.40 

5.80 

2.40 

80 

4.00 

0.80 

1.90 

0.40 

r  5.50 

4.50 

80 

3.60 

2.70 

1.30 

0.80 

The  data  given  in  Tables  CL,  CLI  and  CLII  show  that  when  filtered  sewage, 
mixed  with  land  or  sea  water  containing  various  amounts  of  oxygen,  is  incubated 
the  loss  of  oxygen  is  proportionally  much  greater  when  the  water  contains  the  most 
oxygen. 


Oxygen  Consumed  by  Sludge 
The  beds  of  sludge  formed  in  the  harbor  by  deposits  of  suspended  matter  in  sewage 
undergo  fermentation  and  exhaust  the  oxygen  from  the  overlying  harbor  water.  In 
order  to  determine  how  rapidly  the  consumption  of  oxygen  proceeds  sludge,  dredged 
from  the  slip  at  Pier  4,  East  river,  on  July  17,  1913,  was  placed  in  a  bottle. 


736         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

Aerated  water,  collected  on  the  same  day  off  South  Ferry,  was  poured  into  the 
bottle,  care  being  taken  to  disturb  the  sludge  as  little  as  possible.  The  sample  was 
incubated  for  2-1  hours  at  an  average  temperature  of  75°  F.  and  tested  for  oxygen.  The 
data  obtained  are  given  in  Table  CLIII. 


TABLE  CLIII 

Consumption  of  Oxygen  by  Harbor  Water  During  Incubation  Over  Sludge  Dredged 

From  the  Harbor  Bottom 


Sample  of  Harbor  Water 

Aver. 
Temp. 
Deg.  F. 

Dissolved  Oxygen 
C.  C.  per  Litre 

Initial 

After  Standing  for 

Over  10  per  cent,  of  Harbor  Sludge  

80 

4.18 

24  hours 
0.10 

The  data  given  in  Table  CLIII  show  that  the  oxygen  contained  in  the  harbor  water 
was  exhausted  by  the  harbor  sludge  in  24  hours. 

Conclusions 

The  data  presented  in  the  preceding  tables  in  regard  to  the  changes  which  take 
place  in  harbor  water  during  incubation  show  that  the  dissolved  oxygen  was  always 
largely  reduced. 

Samples  collected  in  winter  lose  from  4  to  5  c.c.  of  oxygen,  while  in  summer  they 
lose  only  1  or  2  c.c.  This  fact  indicates  that  the  low  temperatures  of  winter  retard  the 
bacterial  decomposition  of  sewage  entering  the  harbor,  thereby  throwing  an  extra 
burden  in  summer  upon  the  digestive  capacity  of  the  harbor  water.  This  heavy  burden 
is  placed  upon  the  water  at  a  time  when  the  available  supply  of  dissolved  oxygen  is 
reduced  on  account  of  the  prevailing  high  temperature  of  the  water. 

Compounds  containing  nitrogen  in  the  harbor  water  also  undergo  marked  changes 
during  incubation,  albuminoid  ammonia  and  nitrates  decrease,  whereas  free  ammonia 
and  nitrites  increase.  This  indicates  clearly  that  the  waters  receiving  sewage  from  the 
metropolitan  district  contain  quantities  of  undigested  organic  matter. 

Unpolluted  sea  water  loses  very  little  oxygen  during  incubation  and  land  water 
from  the  public  water  supply  loses  comparatively  little.  But  when  more  than  10  per 
cent,  of  either  raw  or  settled  sewage  is  mixed  with  sea,  harbor  or  land  water  and  incu- 
bated, even  though  saturated  with  oxygen,  all  the  oxygen  will  disappear  in  from  6  to  12 


CONSUMPTION  OF  OXYGEN  ON  INCUBATION  737 

hours.  Five  per  cent,  of  either  raw  or  settled  sewage  exhausts  the  oxygen  from  aerated 
waters  in  from  20  to  24  hours,  but  3  per  cent,  does  not  exhaust  the  oxygen  for  5  days. 

Sewage  from  which  the  gross  solids  have  been  removed  by  sedimentation  for  two 
hours  exhausts  oxygen  a  little  less  rapidly  than  raw  sewage  during  the  first  few  hours 
of  incubation.  Either  raw  or  settled  sewage,  however,  makes  a  continuous  drain  for 
many  hours  upon  the  oxygen  which  is  dissolved  in  harbor  water. 

The  volume  of  oxygen  required  to  oxidize  the  sewage  entering  the  harbor  may  be 
estimated  from  data  obtained  by  incubating  5  per  cent,  of  sewage  in  water  collected 
from  the  East  river  when  6  c.c.  of  oxygen  were  consumed  per  litre,  or  1,428  lbs.  per  mil- 
lion gallons  of  raw  sewage.  Assuming  that  the  metropolitan  district  will  produce 
770,000,000  gallons  of  sewage  a  day  in  1915,  the  data  show  that  527  tons  of  oxygen  will 
be  required  to  oxidize  this  sewage. 

Sludge  dredged  from  the  bottom  of  slips  along  the  East  river  absorbed  oxygen 
rapidly,  especially  when  stirred  up.  Therefore  when  passing  boats  churn  up  the  layers 
of  sewage  sludge  deposited  in  slips  or  on  the  harbor  bottom  the  fermenting  organic 
matter  exhausts  the  oxygen  from  a  large  volume  of  the  surrounding  water. 


738         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


SECTION  V 

THE  ABSORPTION  OF  DISSOLVED  OXYGEN  BY  LAND  WATER  AND 
SEA  WATER  AND  MIXTURES  THEREOF 

Samples  of  land  water  and  sea  water  were  boiled  30  minutes  and  siphoned  while 
still  boiling  into  wide-mouthed  jars  holding  one  quart  each.  These  jars  were  9  inches 
high  and  3y2  inches  in  diameter  and  had  mouths  1%  inches  in  diameter.  Each  was 
fitted  with  a  No.  10  rubber  stopper  with  perforations  through  which  glass  tubing  ex- 
tended. The  boiling  water  was  siphoned  into  each  jar  through  a  glass  tube,  and  car- 
bonic acid  was  drawn  in  by  contraction  of  the  water  as  it  cooled  from  a  reservoir  at- 
tached to  the  other  tube.  The  C02  reservoir  Avas  protected  from  contamination  with 
oxygen  by  connecting  the  inlet  to  a  train  of  wash  bottles  charged  with  a  mixture  of 
caustic  soda  and  pyrogallic  acid. 

When  the  jars  were  thoroughly  cooled  the  stoppers  were  removed  from  all  except 
one,  and  the  contents  exposed  to  the  air. 

The  water  in  the  unopened  jar  was  siphoned  into  a  Soper  oxygen  testing  bottle 
and  analyzed  to  determine  how  much  oxygen  was  contained  by  the  water  in  the  jars 
at  the  start.  At  intervals  the  contents  of  the  open  jars  were  siphoned  into  oxygen 
bottles  and  tested. 

The  contents  of  the  jars  were  not  agitated  during  the  period  when  the  samples 
were  absorbing  oxygen. 

Adsorption  by  Land  Water 

The  results  obtained  for  land  water  are  shown  in  Tables  CLIV  to  CLVII,  in- 
clusive: 


TABLE  CLIV 
Dissolved  Oxygen  Absorbed  by  Land  Water 


Time  Exposed  to  Air 

Specific 
Gravity 

Temp. 
Dec.  F. 

C.  C.  per 
Liter 

Dissolv 

Per  Cent. 
Saturation 

ed  Oxygen 

Gain  per  hour 
since  last  test 

Gain  per 
24  hours 

1000 

68 

0.14 

2 

1000 

68 

0.86 

13 

11% 

1000 

68 

1.43 

22 

9% 

1000 

68 

1.86 

29 

7% 

4  hours  

1000 

68 

2.14 

33 

4% 

5  hours  

1000 

68 

2.43 

37 

4% 

1000 

68 

2.57 

40 

3% 

1000 

68 

2.71 

42 

2% 

1000 

68 

2.86 

44 

2% 

1000 

68 

3.71 

57 

0.8% 

55% 

ABSORPTION  OF  OXYGEN  739 
TABLE  CLV 


Dissolved  Oxygen  Absorbed  by  Land  Water 


Time  Exposed  to  Air 

Specific 
Gravity 

Temp. 
Deg.  F. 

C.  C.  per 
Liter 

Dissolv 

Per  Cent. 
Saturation 

ed  Oxygen 

Gain  Since 
Exposed 

Gain  per 
24  Hours 

Initial  

1000 

70 

0.28 

4 

0.0% 

00% 

24  hours  

1000 

70 

3.57 

56 

52.0% 

52.0% 

2  days  

1000 

70 

4.43 

70 

66.0% 

14.0% 

3  days  

1000 

70 

5.14 

80 

76.0% 

10.0% 

4  days  

1000 

70 

5.71 

89 

85.0% 

9.0% 

5  days  

1000 

70 

5.86 

92 

88.0% 

3.0% 

6  days  

1000 

70 

GOO 

94 

90.0% 

2.0% 

1000 

70 

6.14 

96 

92.0% 

2.0% 

TABLE  CLVI 
Dissolved  Oxygen  Absorbed  by  Land  Water 


Time  Exposed  to  Air 


Temperature 
Deg.  F. 


Specific 
Gravity 


Dissolved  Oxygen 


C.  C.  per 
Liter 


Per  Cent. 
Saturation 


Gain  per  Hour 
since  last  test 


Gain  per 
24  Hours 


Initial. . . 

1  hour. 

2  hours 

3  hours 

4  hours 

5  hours 

6  hours 

7  hours 

8  hours 
24  hours 

2  days. 

3  days. 

4  days. 

6  days. 

7  days. 
10  days. 


70 
70 
70 
70 
70 
70 
70 
70 
70 
70 
70 
70 
70 
70 
70 
70 


1000 
1000 
1000 
1000 
1000 
1000 
1000 
1000 
1000 
1000 
1000 
1000 
1000 
1000 
1000 
1000 


0.28 
1.00 
1.57 
2.00 
2.28 
2.57 
2.71 
2.85 
3.00 
3.71 
4.43 
5.14 
5.57 
6.00 
6.14 
6.76 


4 

16 
25 
31 
35 
40 
43 
45 
47 
58 
70 
80 
87 
94 
96 
100 


12% 
9% 
6% 
4% 
5% 
3% 
2% 
2% 

0.70% 
0.50% 
0.42% 
0.30% 
0.15% 
0.08% 
0.06% 


54% 

12% 

10% 
7% 
3.5% 
2.0% 
1.3% 


TABLE  CLVII 
Dissolved  Oxygen  Absorbed  by  Land  Water 


Time  Exposed  to  Air 


Temperature 
Deg.  F. 


Specific 
Gravity 


Dissolved  Oxygen 


C.  C.  per 
Liter 


Per  Cent. 
Saturation 


Gain  per  Hour 
since  last  test 


Gain  per 
24  Hours 


Initial. . 

1  hour. 

2  hours 

3  hours 

4  hours 

5  hours 

6  hours 

7  hours 

8  hours 
16  hours 
24  hours 

2  days. 

3  days. 

4  days. 

6  days. 

7  days. 
10  days. 


65 
65 
65 
65 
65 
65 
65 
65 
65 
65 
65 
65 
65 
65 
65 
65 
65 


1000 
1000 
1000 
1000 
1000 
1000 
1000 
1000 
1000 
1000 
1000 
1000 
1000 
1000 
1000 
1000 
1000 


0.27 
0.92 
1.53 
1.90 
2.29 
2.57 
70 
84 
98 
51 
78 
73 


5.41 

6.22 
6.35 
6.49 
6.62 


4 
14 

23 
30 
34 
38 
40 
42 
44 
52 
58 
70 
80 
92 
94 
96 
98 


10% 
9% 
7% 
4% 
4% 
2% 
2% 
2% 
1% 

0.75% 
0.50% 
0.42% 
0.25% 
0.08% 
0.08% 
0.08% 


54% 
12% 
10% 

6% 
2% 
2% 


/o 


740 


DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


Tables  CLIV  to  CLVII  show  that  a  rapid  absorption  took  place  for  the  first  few- 
hours,  the  rate  diminishing  with  each  succeeding  hour.  The  rate  was  much  more 
rapid  for  the  first  day  than  for  the  days  following,  decreasing  with  each  succeeeding 
day. 

Absorption  by  Sea  Water 
The  results  obtained  for  sea  water  are  shown  in  Tables  CLVIII  to  CLXI,  inclusive  : 

TABLE  CLVIII 
Oxygen  Absorbed  by  Sea  Water 


Time  Exposed  to  Air 


Specific 
Gravity 


Temperature 
Deg.  F. 


Dissolved  Oxygen 


C.  C.  per 
iter 


Per  Cent. 
Saturation 


Gain  per  Hour 
since  last  test 


Gain  per 
24  Hours 


Initial. . . 

1  hour. 

2  hours 

3  hours 

4  hours 
f  5  hours 
j  6  hours 
{ 7  hours 
i  8  hours 
24  hours 


1020 
1020 
1020 
1020 
1020 
1020. 
1020. 
1020. 
1020 
1021 


68 
68 
68 


68 
68 
68 
68 
68 


0.14 
0.71 
1.28 
1.71 
2.00 
2.28 
2.57 
2.71 
2.86 
3.43 


2 
13 
23 
30 
36 
41 
46 
48 
51 
61 


11% 
10% 

7% 

6% 

5% 

5% 

2% 

3% 

0.62% 


59% 


TABLE  CLIX 


Oxygen  Absorbed  by  Sea  Water 


Time  Exposed  to  Air 

Specific 
Gravity 

Temperature 
Deg.  F. 

C.  C.  per 
Liter 

Dissolved 

Per  Cent. 
Saturation 

Oxygen 

Gain  Since 
Exposed 

Gain  per 
24  Hours 

1022 

70 

0.28 

4 

24  hours  

1023 

70 

3.43 

65 

61% 

61% 

1023 

70 

4.28 

81 

77% 

16% 

1023 

70 

4.71 

90 

86% 

9% 

1023.5 

70 

5.00 

94 

90% 

4% 

1024 

70 

5.14 

97 

93% 

3% 

1024 

70 

5.14 

97 

93% 

0% 

7  days  

1024 

70 

5.29 

99 

95% 

2% 

ABSORPTION  OF  OXYGEN 


741 


TABLE  CLX 
Oxygen  Absorbed  by  Sea  Water 


Time  Exposed  to  Air 


Temperature 
Deg.  F. 


•Specific 
Gravity 


Dissolved  Oxygen 


C.  C.  per 
Liter 

Per  Cent. 
Saturation 

0.14 

3 

0.71 

13 

1.25 

22 

1.67 

30 

1.95 

35 

2.22 

40 

2.50 

45 

2  64 

48 

2.78 

50 

3.34 

60 

3.61 

65 

4.45 

81 

5.00 

91 

5.28 

96 

5.42 

98 

5.42 

98 

5.55 

100 

Gain  per  Hour 
since  last  test 


Gain  per 
24  Hours 


Initial . . , 

1  hour. 

2  hours 

3  hours 

4  hours 

5  hours 

6  hours 

7  hours 

8  hours 
16  hours 
24  hours 

2  days. 

3  days. 

5  days . 

6  days. 

7  days. 
10  days. 


65 
65 
65 
65 
65 
65 
65 
65 
65 
65 
65 
65 
65 
65 
65 
65 
65 


1023.5 
1023.5 
1023.5 
1024.0 
1024.0 
1024.0 
1024.5 
1025.0 
1025.0 
1025.5 
1025.5 
1025.5 
1025.5 
1026.0 
1026.0 
1026.0 
1026.0 


10% 
9% 
8% 
5% 
5% 
5% 
3% 
2% 
1.25% 
0.63% 
0.67% 
0.42% 
0.10% 
0.08% 
0.00% 
0.03% 


62% 

16% 

10% 
25% 
20% 
0.0% 
0.7% 


*The  specific  gravity  of  the  sea  water  was  increased  by  evaporation  during  the  period  of  boiling. 

TABLE  CLXI 
Oxygen  Absorbed  by  Sea  Water 


Time  Exposed  to  Air 


Temperature 
Deg.  F. 


•Specific 
Gravity 


65 

1027.5 

65 

1027.5 

65 

1027.5 

65 

1027.5 

65 

1027.5 

65 

1028.0 

65 

1028.0 

65 

1028.0 

65 

1028.0 

65 

1028.0 

65 

1028.0 

65 

1028.0 

65 

1028.0 

65 

1028.0 

65 

1028.0 

65 

1028.5 

67 

1028.5 

Dissolved  Oxygen 


C.  C.  per 
Liter 

Per  Cent. 
Saturation 

0.13 

2 

0.68 

13 

1.22 

23 

1.62 

30 

1.89 

35 

2.17 

40 

2.30 

43 

2.43 

45 

2.57 

48 

2.98 

55 

3.38 

62 

4.19 

78 

4.73 

88 

5.00 

93 

5.14 

95 

5.27 

97 

5.27 

99 

Gain  per  Hour 
since  last  test 


Gain  per 
24  hours 


Initial . . , 

1  hour. 

2  hours 

3  hours 

4  hours 

5  hours 

6  hours 

7  hours 

8  hours 
16  hours 
24  hours 

2  days. 

3  days. 

4  days . 

5  days. 

6  days. 

7  days. 


11% 
10% 

7% 
5% 
5% 
3% 
2% 
3% 

0.87% 
0.87% 
0.67% 
0.42% 
0.21% 
0.08% 
0.08% 
0.08% 


60% 
16% 
10% 

5% 
2% 
2% 
2% 


*The  specific  gravity  of  the  sea  water  was  increased  by  evaporation  during  the  period  of  boiling. 


Tables  CLVIII  to  CLXI  show  the  same  general  behavior  of  sea  water  as  shown  for 
land  water  in  Tables  CLIV  to  CLVII.  The  rate  of  absorption  was  rapid  upon  first 
exposure  to  the  air  and  diminished  with  time,  until  near  the  point  of  saturation,  when 
the  absorption  proceeded  very  slowly. 

By  a  comparison  of  the  results  obtained  with  land  water  and  sea  water,  it  is  seen 
that  the  latter  recovers  its  oxygen  at  a  slightly  more  rapid  rate  than  the  former.  The 


742 


DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


difference  was  first  apparent  at  about  the  third  hour  after  exposure  to  the  air,  and 
amounted  to  4  or  5  per  cent,  at  the  end  of  24  hours. 

Absorption  by  Mixtures  of  Land  and  Sea  Water 

The  results  obtained  in  experiments  with  mixtures  are  shown  in  Tables  CLXII 
and  CLXIII. 


TABLE  CLXII 
Oxygen  Absorbed  by  Land  Water  Mixed  with  Sea  Water 


Time  Exposed  to  Air 


Specific 
Gravity 


Temperature 
Deg.  F. 


Dissolved  Oxygen 


C.  C  per 
Liter 


Per  Cent. 
Saturation 


Gain  per  Hour 
since  last  test 


Gain  per 
24  Hours 


Initial. . . 

1  hour. 

2  hours 

3  hours 

4  hours 

5  hours 

6  hours 

7  hours 

8  hours 
24  hours 


1006.5 
1006.5 
1006.5 
1006.5 
1006.5 
1006.5 
1006.5 
1006.5 
1006.5 
1007.0 


68 
68 
68 
68 
68 
68 
68 
68 
68 
68 


0.28 
0.86 


43 
86 
14 
43 
63 
86 
00 
86 


4 
14 

23 
30 
34 
39 
42 
46 
48 
62 


10% 
9% 
7% 
4% 
5% 
3% 
4% 
2% 

0.87% 


58% 


TABLE  CLXIII 


Oxygen  Absorbed  by  Land  Water  Mixed  with  Sea  Water 


Time  Exposed  to  Air 

Specific 
Gravity 

Temperature 
Deg.  F. 

C.  C.  per 
Liter 

Dissolved 

Per  Cent. 
Saturation 

Oxygen 

Gain  per  Hour 
since  last  test 

Gain  per 
24  Hours 

Initial  

1011.5 

70 

0.28 

5 

1012.0 

70 

3.43 

60 

55% 

55% 

1012.5 

70 

4.28 

74 

69% 

14% 

1012.5 

70 

4.86 

84 

79% 

10% 

1012.5 

70 

5.28 

91 

86% 

7% 

1012.5 

70 

5.43 

94 

89% 

3% 

1012.5 

70 

5.57 

96 

91% 

2% 

1012.5 

70 

5.63 

97 

92% 

1% 

Tables  CLXII  and  CLXIII  show  that  the  mixture  of  land  and  sea  water  behaved 
in  the  same  general  way  as  either  land  or  sea  water,  as  regards  the  rate  of  absorption. 
Tbe  rate  was  somewhat  less  than  that  of  undiluted  sea  water,  and  slightly  greater  than 
that  of  land  water. 


ABSORPTION  OF  OXYGEN  743 
Conclusions 

1.  Land  or  sea  water,  from  which  the  dissolved  oxygen  has  been  exhausted  will 
absorb  oxygen  rapidly  from  the  atmosphere  if  exposed  to  the  air  in  an  open  vessel. 

2.  The  rate  of  absorption  is  especially  rapid  during  the  first  hour,  but  decreases  as 
the  degree  of  saturation  increases,  until  the  saturation  figure  is  approached,  when  the 
rate  declines  to  less  than  1  per  cent,  per  24  hours.  Thus  10  per  cent,  of  the  saturation 
value  was  taken  up  in  the  first  hour,  over  50  per  cent,  in  the  first  day,  and  seven  to  ten 
days  were  required  for  saturation. 

3.  The  rate  of  absorption  was  found  to  be  rather  more  rapid  in  sea  than  in  land 
water,  figured  in  terms  of  the  per  cent,  of  saturation.  The  gain  for  the  first  day  was 
about  8  per  cent,  greater  in  sea  water  than  in  land  water. 

4.  A  mixture  of  land  and  sea  water  showed  the  same  general  characteristics  as  to 
reabsorption  of  oxygen  as  were  possessed  by  the  ingredients  separately.  The  rate  of 
absorption  lay  between  the  rates  for  unmixed  land  and  sea  water. 

5.  The  rate  of  absorption  was  very  uniform  for  samples  of  a  like  character. 


744         DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 


SECTION  VI 

CHEMICAL  ANALYSES  OF  THE  HARBOR  WATER 

INTRODUCTION 

Samples  of  water  collected  from  various  parts  of  the  harbor  were  analyzed  for 
free  and  albuminoid  ammonia,  nitrites,  nitrates  and  oxygen  between  February  27, 
1912,  and  June  11,  1913,  and  the  results  are  recorded  in  the  following  tables.  In  most 
cases  duplicate  samples  were  incubated  and  the  condition  of  the  water  before  and  after 
incubation  is  here  presented. 

The  samples  were  incubated  for  7  days  at  the  temperature  and  in  the  diffused 
light  of  the  laboratory.  Tests  for  nitrates  and  nitrites  were  made  from  the  original 
samples  on  the  day  when  they  were  collected  and  from  the  incubated  samples  at  the  end 
of  a  week.  Some  tests  for  free  and  albuminoid  ammonia  were  made  on  the  day  of  col- 
lection and  some  on  the  following  day,  that  part  of  the  sample  which  was  not  at  once 
analyzed  being  preserved  by  means  of  chloroform. 


CHEMICAL  ANALYSES  OF  HARBOR  WATER 


745 


TABLE  CLXIV 

Section 

No.  Location  Date  of  Collection  Pages 

1  East  river,  midstream,  Brooklyn  Bridge  Feb.  27,  1912,  to  June  11,  1913   746 

2  Hudson  river,  midstream,  off  Pier  A  Feb.  27,  1912,  to  June  11,  1913   748 

3  Robbins  Reef,  near  bell  buoy  Feb.  27,  1912,  to  June  11,  1913   750 

4  Kill  van  Kull,  midstream,  off  Sailors  Snug  Harbor  Mar.  4,  1912,  to  June  11,  1913   753 

5  Narrows,  between  Forts  Lafayette  and  Wadsworth  Feb.  27,  1912,  to  June  11,  1913   755 


746  DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

TABLE  CLXIV 
1— EAST  RIVER,  MIDSTREAM,  BROOKLYN  BRIDGE 


Latitude  40°  42'  20".    Longitude  73°  59'  48". 


Oxygen 

Parts  per  Million 

Sample 
No. 

Date 
1912 

Hour 
A.  M. 

i'  eet 
below 
surface 

Tidal 
current 

Incuba- 
tion 

1  emp. 
water 
Deg.  C. 

C.  C. 
per 
litre 

Per  cent, 
satura- 
tion 

Ammonia 

Nitrite 

Nitrate 

Albu- 
minoid 

Free 

1 

9 

w 

Feb.  27 

10.30 

1 

OU 

Slack 

low  water 
oiacK 

low  water 

Before 
Before 

2.2 
3.3 

6.57 
6.57 

80 
80 

0.548 
0.442 

0.102 
0.198 

0.001 
0.001 

0.189 
0.149 

9 

Mar.  4 

10.30 

l 

30 

Ebb 

Before 
ijciore 

1.7 

9  9 

6.57 
6.57 

79 
80 

0.236 
0.272 

0.284 
0.324 

0.001 
0.001 

0.109 
0.139 

19 
20 

Mar.  5 

6.05 
6.10 

1 

30 

Flood 
Flood 

Before 
Before 

0.6 
1.1 

6.86 
6.86 

80 
80 

0.316 

U .  Z4U 

0.240 
u .  iy^ 

0.001 
0.001 

0.179 
0.139 

29 
29a 

Mar.  14 

11.15 
11.15 

1 
1 

Ebb 
Ebb 

Before 
After 
Difference 

4.4 
21.1 

6.43 
2.28 
-4.15 

80 
40 
-40 

0.400 

0.324 
0.468 

-|-U .  144 

0.001 
0.002 
+0.001 

0.239 

ou 

30a 

iviur.  It 

1 1  90 

11.20 

30 

30 

EjUU 

Ebb 

After 
Difference 

d  d 

*± .  t 

21.1 

6.43 
2.10 
-4.33 

80 
37 
-43 

0.408 

0.348 
0.524 
+0.176 

0.001 
0.003 
+0.002 

0.259 

3Q 

39a 

April  o 

O .  OU 

8.50 

1 
1 

1 

r  100  Q 

Flood 

Before 
After 
Difference 

R  1 

18.3 

6.71 
3.92 
-2.79 

82 
61 
-21 

0.244 
0.192 
-0.052 

0.168 
0.240 
+0.072 

0.001 
0.001 
0.000 

0.149 
0.149 
0.000 

40 

TtOA 

April  3 

9.00 
y .  uu 

30 

OU 

Flood 
r  iooq 

Before 

A  ft  or 

Alter 
Difference 

6.1 
1  c 

lo .  o 

6.57 
3.78 
-2.79 

81 
60 
-21 

0.256 
0.168 
-0.088 

0.148 
0.220 
+0.072 

0.001 
0.001 
0.000 

0.109 
0.129 
+0.020 

57a 

April  O 

P.  M. 

O  .  DU 

5.50 

1 
1 

l 

H/DD 

Ebb 

Before 
After 
Difference 

A  1 
0. 1 

18.3 

6.71 
3.47 
-3.24 

82 
53 
-29 

0.256 
0.184 
-0.072 

0.160 
0.212 
+0.052 

0.001 
0.001 
0.000 

0.199 
0.089 
-0.110 

58 

OoA 

April  3 

6.00 
o .  UU 

30 

oU 

Ebb 

IliDD 

Before 

A  ft  ay 

Alter 
Difference 

6.1 
lo .  o 

6.43 
3.11 
-3.32 

80 
49 
-31 

0.216 
-0.076 

v .  lot 
0.200 
+0.048 

0.001 
0.002 
+0.001 

0.149 
0.158 
-t-u .  uuy 

61 

DI A 

June  13 

A.  M. 

10.10 
in  in 

1 

1 
1 

Ebb 

Before 
Alter 
Difference 

17.2 

91  1 

3.88 
2.76 
-1.12 

65 
48 
-17 

0.340 
0.272 
-0.068 

0.160 
0.144 
-0.016 

0.002 
0.005 
+0.003 

0.028 

yj .  UrtO 

+0.017 

62 

O.SA 

June  13 

10. 15 

1 0   1  £ 
1U .  10 

30 

oU 

Ebb 

HiDD 

Before 
Alter 
Difference 

16.7 

91  1 
41 . 1 

3.88 
2.86 
-1.02 

64 
51 
-13 

0.284 
0.208 
-0.076 

0.144 
0.284 
+0.140 

0.002 

u .  UUO 

+0.001 

0.038 
u .  uo/ 
-0.001 

79 
79a 

June  13 

P.  M. 
4.30 
4.30 

1 
1 

Flood 
Flood 

Before 
After 
Difference 

17.2 
21.1 

3.68 
2.86 
-0.82 

60 
50 
-10 

0.172 
0.248 
+0.076 

0.156 
0.188 
+0.032 

0.002 
0.007 
+0.005 

0.058 
0.073 
+0.015 

80 
80a 

June  13 

A.  M. 
4.35 
4.35 

30 
30 

Flood 
Flood 

Before 
After 
Difference 

16.7 
21.1 

3.68 
2.55 
-1.13 

61 
45 
-16 

0.204 
0.160 
-0.044 

0.108 
0.356 
+0.248 

0.002 
0.008 
+0.006 

0.078 
0.052 
-0.026 

81 
81a 

July  11 

9.00 
9.00 

1 
1 

Ebb 
Ebb 

Before 
After 
Difference 

23.6 
24.4 

2.40 
0.70 
-1.70 

46 
13 
-33 

0.312 
0.196 
-0.116 

0.380 
0.608 
+0.228 

0.003 
0.056 
+0.053 

0.087 
0.013 
-0.074 

82 
82a 

July  11 

9.10 
9.10 

30 
30 

Ebb 
Ebb 

Before 
After 
Difference 

23.6 
24.4 

2.40 
0.70 
-1.70 

46 
13 
-33 

0.284 
0.212 
-0.072 

0.408 
0.624 
+0.216 

0.003 
0.000 
0.003 

0.097 
0.020 
0.077 

CHEMICAL  ANALYSES  OF  HARBOR  WATER  747 
TABLE  CLXIV— Continued 


1— EAST  RIVER,  MIDSTREAM,  BROOKLYN  BRIDGE— Continued 


Oxygen 

Parts  per  Million 

Sample 

IN  0. 

Date 
i  m  o 

Hour 

r.  Ivl. 

r  eet 

below 
surface 

Tidal 
current 

Incuba- 
tion 

Temp 
water 
Deg.  C. 

C.  C. 
per 
litre 

Per  cent, 
satura- 

Ammonia 

Nitrite 

Nitrate 

tion 

AH-in- 

minoid 

Free 

99 

July  11 

3.30 

1 

Flood 

Before 

23.9 

2.60 

50 

0.272 

0.452 

0.003 

0.087 

99a 

3.30 

1 

Flood 

After 

24.4 

0.80 

15 

O  919 

0  560 

0.056 

0.000 

1  ^  i  fT  nrpn  pp 

-1.80 

-35 

-0.060 

+0i'l08 

+0.053 

-0.087 

100 

July  11 

3.35 

30 

Flood 

Before 

23.9 

2.60 

50 

0.212 

0.456 

0.003 

0 .  0o7 

100a 

3.35 

30 

Flood 

After 

24.4 

0.80 

15 

O  4^9 

0.153 

0.037 

Difference 

-1.80 

-35 

-0.032 

-0.024 

+0.150 

-0.020 

A.  M. 

101 

July  24 

9.30 

1 

Ebb 

Before 

21.7 

2.50 

46 

0.328 

0.548 

0.070 

0.060 

10lA 

9.30 

1 

Ebb 

After 

23.9 

0.60 

11 

0  160 

0.608 

0.072 

0.038 

DifF^ronpp 
lj  i  1 1  ci  cucc 

-1.90 

-35 

-0^168 

+0^060 

+0.002 

-0.022 

102 

July  24 

9.35 

30 

Ebb 

Before 

21.7 

2.50 

46 

0.200 

0.520 

O.Ooo 

A    fH  A 

0 . 044 

102a 

9.35 

30 

Ebb 

After 

23.9 

0.70 

13 

fi  1 1  fi 

ft  ^fi 

0.072 

0.028 

Difference 

-1.80 

-33 

-0.084 

+0.016 

+0.006 

-0.016 

P.  M. 

119 

July  24 

.  3.40 

1 

Flood 

Before 

21.7 

2.80 

50 

O  IfiO 

0  4^(1 

0.080 

0.000 

119a 

3.40 

1 

Flood 

After 

23.9 

1.00 

19 

0.108 

0.540 

0.112 

0.000 

iff  prpnpp 
.L^lll  CI  trlli-  C 

-1.80 

-31 

-0.052 

+0.084 

+0.032 

0.000 

120 

July  24 

3.45 

30 

Flood 

Before 

21.1 

2.80 

51 

f>  9f)fl 

fl  4R0 

0.078 

0.032 

120a 

3.45 

30 

Flood 

After 

23.9 

1.20 

23 

0.092 

0.492 

0 . 120 

0.000 

l)  i  ft  prpn  PP 
LsllL  CI  ClIlsC 

-1.60 

—  9S 

-0.108 

+0.032 

+0.042 

-0.032 

1913 

A.  M. 

313 

Jan.  9 

7.45 

1 

Flood 

Before 

2.8 

6.00 

68 

fl  9f)4 

fl  1  fiS 

U  .  lOo 

0.016 

0.144 

313a 

7  4.  "5 

i 
± 

After 

26.7 

4.60 

71 

0.156 

0.260 

0.020 

0.110 

Difference 

-1.40 

+3 

-0.048 

+0.092 

+0.004 

-0.034 

323 

Jan.  9 

11.20 

1 

Ebb 

Before 

3.3 

5.60 

65 

ft  i  d-d 

fi  i  *;fi 

u .  lOO 

0.020 

0.140 

323a 

11.20 

1 

Ebb 

After 

26.7 

4.80 

86 

0.096 

0.164 

0  016 

0.144 

I)  ifT  prPtl  PP 

-0.80 

i^i 

-0.048 

+0.008 

-0.004 

+0.004 

333 

Feb.  18 

10.00 

1 

Ebb 

Before 

1.7 

5.40 

62 

ft  *3 1 0 

0.036 

0. 114 

333a 

10.00 

1 

Ebb 

After 

1.7 

2.00 

38 

0.192 

0.440 

0  042 

0.048 

it  i  fTprpn  pp 
.L/illci  cll^c 

-3.40 

-24 

-0.112 

+0.128 

+0.006 

-0.066 

334 

Feb.  18 

10.05 

30 

Ebb 

Before 

1.7 

5.40 

62 

U.ZlJU 

U .  ZUa 

0.030 

0.140 

334a 

10.05 

30 

Ebb 

After 

1.7 

3.00 

57 

0.168 

0.320 

0  034 

0.126 

Difference 

-2.40 

-5 

-0.032 

+0.112 

+0.004 

-0.014 

P.  M. 

351 

Feb.  18 

5.10 

1 

Flood 

Before 

1.7 

5.60 

64 

0.204 

0. 192 

0.024 

0.166 

^  1  A 

p;  in 

1 
1 

r  looQ 

A  ff  or 

ai  ier 

91  1 

3.10 

55 

0.092 

0.244 

0  024 

0.166 

Difference 

-2.50 

-9 

-0.112 

+0.052 

0.000 

0.000 

352 

Feb.  18 

5.15 

30 

Flood 

Before 

1.7 

5.70 

65 

0.160 

0.204 

0.024 

0.286 

352a 

5.15 

30 

Flood 

After 

21.1 

3.40 

60 

0.148 

0.296 

0.026 

0.214 

Difference 

-2.30 

-5 

-0.012 

+0.092 

+0.002 

-0.072 

397 

May  29 

3.05 

1 

Flood 

Before 

15.3 

4.70 

72 

0.108 

0.252 

0.034 

0.056 

397a 

3.05 

1 

Flood 

After 

21.6 

3.39 

59 

0.116 

0.352 

0.042 

0.088 

Difference 

-1.31 

-13 

+0.008 

+0.100 

+0.008 

+0.032 

399 

May  29 

3.30 

30 

Flood 

Before 

15.0 

2.90 

45 

0.120 

0.272 

0.029 

0.021 

399a 

3.30 

30 

Flood 

After 

21.6 

2.31 

40 

0.120 

0.392 

0.040 

0.040 

Difference 

-0.59 

-5 

-0.000 

+0.120 

+0.011 

+0.019 

A.  M. 

412 

June  11 

9.05 

1 

Ebb 

Before 

16.5 

2.49 

40 

0.256 

0.460 

0.044 

0.096 

412a 

9.05 

1 

Ebb 

After 

16.7 

0.00 

0 

0.096 

0.384 

0.050 

0.060 

Difference 

-2.49 

-40 

-0.160 

-0.076 

+0.006 

-0.036 

748  DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

TABLE  CLXIV— Continued 


1— EAST  RIVER,  MIDSTREAM,  BROOKLYN  BRIDGE— Continued 


Oxygen 

Parts  per  Million 

Sample 
No. 

Date 
1913 

Hour 
A.  M. 

Feet 
below 
surface 

Tidal 

pi  i  n*  pn  t. 

Incuba- 
tion 

Temp, 
water 
Deg.  C. 

C.  C. 
per 
litre 

Per  cent, 
satura- 
tion 

Ammonia 

Nitrite 

Nitrate 

Albu- 
minoid 

Free 

414 
414a 

June  11 

9.25 
9.25 

30 
30 

Ebb 
Ebb 

Before 
After 
Difference 

16.5 
16.7 

2.51 
0.00 
-2.51 

41 
0 

-41 

0.268 
0.104 
-0.164 

0.484 
0.360 
-0.124 

0.044 
0.076 
+0.032 

0.076 
0.074 
-0.002 

427 
427a 

June  11 

P.  M. 
1.05 
1.05 

1 
1 

Flood 
Flood 

Before 
After 
Difference 

18.4 
18.4 

4.83 
1.80 
-3.03 

85 
30 
-55 

0.188 
0.192 
+0.004 

0.316 
0.604 
+0.288 

0.040 
0.054 
+0.014 

0.120 
0.116 
-0.004 

429 
429a 

June  11 

1.25 
1.25 

30 
30 

Flood 
Flood 

Before 
After 
Difference 

17.8 
17.8 

5.08 
2.83 
-2.25 

84 
47 
-37 

0.184 
0.192 
+0.008 

0.316 
0.652 
+0.336 

0.040 
0.130 
+0.090 

0.090 
0.040 
-0.050 

2— HUDSON  RIVER,  MIDSTREAM,  OFF  PIER  A 


Latitude  40°  42'  19".    Longitude  74°  01'  34". 


3 
4 

1912 
Feb.  27 

A.M. 
11.30 
11 .40 

1 

30 

Ebb 
Ebb 

Before 
Before 

2.8 
2.8 

6.57 
6.57 

80 
80 

0.446 
0.438 

0.426 
0.196 

0.001 
0.001 

0.199 
0.209 

11 

12 

Mar.  4 

11.00 
11.05 

1 

30 

Ebb 
Ebb 

Before 
Before 

1.1 
1.7 

6.86 
6.86 

81 

82 

0.192 
0.232 

0.304 
0.300 

0.001 
0.001 

0.139 
0.119 

21 

22 

Mar.  5 

6.25 
6.30 

1 

30 

Flood 
Flood 

Before 
Before 

0.6 
1.1 

7.00 
7.00 

81 

82 

0.196 
0.196 

0.216 
0.216 

0.001 
0.001 

0.239 
0.189 

31 

3lA 

Mar.  14 

11.50 
11.50 

1 
1 

Ebb 
Ebb 

Before 
After 
Difference 

3.3 
21.1 

6.86 
2.86 
-4.00 

76 
32 
-44 

0.172 

0.152 
0.380 
+0.228 

0.000 
0.002 
+0.002 

0.250 

32 
32a 

Mar.  14 

Noon 
12.00 
12.00 

30 
30 

Ebb 
Ebb 

Before 
After 
Difference 

3.9 
21.1 

6.43 
2.57 
-3.86 

80 
29 
-51 

0.236 

0.284 
0.316 
+0.032 

0.001 
0.001 
0.000 

0.169 

41 

41a 

April  3 

A.  M. 
9.30 
9.30 

1 
1 

Ebb 
Ebb 

Before 
After 
Difference 

5.6 
18.3 

7.43 
4.46 
-2.97 

85 
68 
-17 

0.200 
0.172 
-0.028 

0.164 
0.196 
+0.032 

0.000 
0.001 
+0.001 

0.190 
0.139 
-0.051 

42 
42a 

April  3 

9.40 
9.40 

30 
30 

Flood 
Flood 

Before 
After 
Difference 

6.1 
18.3 

6.80 
4.32 
-2.48 

83 
68 
-15 

0.232 
0.172 
—0.060 

0.160 
0.224 
+0.064 

0.001 
0.001 
0.000 

0.169 
0.089 
-0.080 

55 
55a 

April  3 

P.  M. 
5.20 
5.20 

1 
1 

Ebb 
Ebb 

Before 
After 
Difference 

6.1 
20.0 

7.57 
3.89 
-3.68 

88 
60 
-28 

0.340 
0.228 
-0.012 

0.128 
0.152 
+0.024 

0.000 
0.001 
+0.001 

0.230 
0.099 
-0.131 

56 
56a 

April  3 

5.30 
5.30 

30 
30 

Ebb 
Ebb 

Before 
After 
Difference 

6.1 
20.0 

7.57 
3.78 
-3.79 

88 
58 
-30 

0.404 
0.344 
-0.060 

0.156 
0.196 
+0.040 

0.000 
0.001 
+0.001 

0.160 
0.169 
+0.009 

63 
63a 

June  13 

A.M. 
10.30 
10.30 

1 
1 

Ebb 
Ebb 

Before 
After 
Difference 

17.2 
21.1 

4.49 
3.16 
-1.33 

74 
54 
-20 

0.180 
0.120 
-0.060 

0.140 
0.300 
+0.160 

0.002 
0.003 
+0.001 

0.028 
0.028 
0.000 

64 
64a 

June  13 

10.40 
10.40 

30 
30 

Ebb 
Ebb 

Before 
After 
Difference 

17.2 
21.1 

4.39 
3.27 
-1.12 

74 
24 
-50 

0.324 
0.160 
-0.164 

0.056 
0.292 
+0.136 

0.002 
0.002 
0.000 

0.028 
0.018 
-0.010 

CHEMICAL  ANALYSES  OF  HARBOR  WATER  749 
TABLE  CLXIV— Continued 


2— HUDSON  RIVER,  MIDSTREAM,  OFF  PD3R  A— Continued 


Oxygen 

Parts  per  Million 

No. 

Date 
1912 

Hour 
P.  M. 

Feet 
below 
surface 

Tidal 
current 

Incuba- 
tion 

Temp, 
water 
Deg.  C. 

C  P 

per 

rer  cent, 
satura- 

Ammonia 

Nitrite 

Nitrate 

btre 

tion 

Albu- 
minoid 

Free 

77 

June  13 

4.10 

1 

Flood 

Before 

17.2 

4.19 

69 

0.128 

0.176 

0.002 

0.038 

77a 

4.10 

1 

Flood 

After 

21.1 

3.16 

56 

0.156 

0.188 

0.006 

0.034 

Difference 

-1.03 

-13 

-0.028 

+0.012 

+0.004 

-0.002 

78 

June  13 

4.15 

30 

Flood 

Before 

16.7 

Oo 

0.168 

0.140 

ft  ftft9 

ft  DfiR 

78a 

4.15 

30 

Flood 

After 

21.1 

2.86 

51 

0.156 

0.256 

0.007 

0.063 

Difference 

-1.33 

-17 

-0.012 

+0.116 

+0.005 

-0.005 

A.M. 

83 

July  11 

9.30 

1 

Ebb 

Before 

23.9 

2.90 

54 

0.328 

0.412 

0.003 

0.077 

83a 

9.30 

1 

Ebb 

After 

24.4 

1.10 

21 

0.120 

0.500 

0.089 

0.000 

Difference 

-1.80 

-33 

-0.208 

+0.088 

+0.086 

-0.077 

84 

July  11 

9.40 

30 

Ebb 

Before 

23.6 

^9 

0.276 

0.420 

ft  ftft3 

ft  ft77 

84a 

9.40 

30 

Ebb 

After 

24.4 

0.60 

n 

0.136 

0.536 

0.045 

0.000 

Difference 

-2.20 

-41 

-0.140 

+0.116 

+0.042 

-0.077 

P.  M. 

97 

July  11 

3.05 

1 

Flood 

Before 

23.9 

3.00 

57 

0.404 

0.436 

0.003 

0.070 

97a 

3.05 

1 

Flood 

After 

24.4 

0.80 

15 

0.156 

0.508 

0.133 

0.007 

Difference 

-2.20 

-42 

-0.248 

+0.072 

+0.130 

-0.063 

98 

July  11 

3.10 

30 

Flood 

Before 

23.9 

3  in 

oy 

0.232 

0.456 

U .  UUo 

u .  uou 

98a 

3.10 

30 

Flood 

After 

24.4 

0.160 

0.584 

0.064 

0.000 

Difference 

— 

-0.072 

+0.128 

+0.061 

-0.080 

A.M. 

103 

July  24 

10.00 

1 

Ebb 

Before 

21.7 

3.10 

55 

0.312 

0.512 

0.063 

0.037 

103a 

10.00 

1 

Ebb 

After 

23.9 

2.00 

37 

0.132 

0.568 

0.048 

0.062 

Difference 

-1.10 

-18 

-0.180 

+0.056 

-0.015 

+0.025 

104 

July  24 

10.05 

30 

Ebb 

Before 

21.7 

O  .  UU 

oo 

0.164 

0.720 

V) .  uoo 

A  AIR 
U.  UIO 

104a 

10.05 

30 

Ebb 

After 

23.9 

2.10 

40 

0  108 

0  540 

0.160 

0.000 

Difference 

-0.90 

-15 

-0.056 

-0.180 

+0.095 

-0.015 

P.  M. 

117 

July  24 

3.15 

1 

Ebb 

Before 

21.7 

3.70 

66 

0.188 

0.428 

0.071 

0.029 

117a 

3.15 

1 

Ebb 

After 

23.9 

2.00 

32 

0.104 

0.528 

0.080 

0.010 

Difference 

-1.70 

-34 

-0.084 

+0.100 

+0.009 

-0.019 

118 

July  24 

3.20 

30 

Flood 

Before 

21.1 

3.70 

67 

0  184 

0  420 

0.073 

0.097 

118a 

3.20 

30 

Flood 

After 

23.9 

2.10 

40 

0.116 

0.372 

0.224 

0.000 

Difference 

-1.60 

—27 

-0.068 

-0.048 

+0.151 

-0.097 

1913 

A.  M. 

315 

Jan.  9 

8.00 

1 

Flood 

Before 

2.8 

6.20 

70 

ft   1  A  v 

U .  148 

0.002 

0.158 

315a 

8.00 

1 

Flood 

After 

26.7 

5.00 

95 

0.112 

0.160 

0.012 

0.188 

Difference 

-1.20 

+25 

-0.036 

+0.052 

+0.010 

+0.030 

325 

Jan.  9 

11.40 

1 

Ebb 

Before 

3.3 

5.70 

65 

0.116 

0.128 

0.016 

0.154 

325a 

11.40 

1 

Ebb 

After 

26.0 

4.40 

79 

0.100 

0.152 

0.016 

0.164 

Difference 

-1.30 

+  14 

-0.016 

+0.024 

0.000 

+0.010 

335 

Feb.  18 

10.30 

1 

Ebb 

Before 

1.7 

5.80 

66 

0.176 

0.228 

0.024 

0.156 

335a 

10.30 

1 

Ebb 

After 

21.1 

4.00 

70 

0.108 

0.300 

0.026 

0.124 

Difference 

-1.80 

+4 

-0.068 

+0.072 

+0.002 

-0.032 

336 

Feb.  18 

10.35 

30 

Ebb 

Before 

1.7 

5.80 

66 

0.132 

0.180 

0.026 

0.084 

336a 

10.35 

30 

Ebb 

After 

21.1 

3.40 

60 

0.108 

0.228 

0.022 

0.108 

Difference 

-2.40 

-6 

-0.024 

+0.048 

-0.004 

+0.024 

P.  M. 

349 

Feb.  18 

4.50 

1 

Flood 

Before 

1.7 

5.80 

65 

0.120 

0.160 

0.022 

0.098 

349a 

4.50 

1 

Flood 

After 

21.1 

4.00 

71 

0.092 

0.144 

0.024 

0.126 

Difference 

-1.80 

+6 

-0.028 

-0.016 

+0.002 

+0.028 

750  DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

TABLE  CLXIV— Continued 


2— HUDSON  RIVER,  MIDSTREAM,  OFF  PEER  A— Continued 


Oxygen 

Parts  per  Million 

No. 

1913 

TT 

riour 
P.  M. 

Feet 
below 
surface 

Tidal 
current 

T  n  pi  i  r*n  - 

tion 

Temp, 
water 
Deg.  C. 

C.  C. 
per 
litre 

Per  cent, 
satura- 
tion 

Ammonia 

Nitrite 

Nitrate 

Albu- 
minoid 

Free 

350 
350a 

Feb.  18 

4.55 
4.55 

30 
30 

Flood 
Flood 

Before 
After 
Difference 

1.7 
21.1 

5.90 
4.00 
-1.90 

67 
71 
+4 

0.136 
0.088 
-0.048 

0.188 
0.212 
+0.024 

0.022 
0.022 
0.000 

0.288 
0.258 
-0.030 

394 
394a 

May  29 

2.00 
2.00 

1 
1 

Flood 
Flood 

Bofore 
After 
Difference 

15.3 
21.6 

4.00 
3.63 
-0.97 

70 
63 
-7 

0.076 
0.096 
+0.020 

0.212 
0.216 
+0.004 

0.030 
0.032 
+0.002 

0.100 
0.098 
-0.002 

396 
396a 

May  29 

2.30 
2.30 

30 
30 

Flood 
Flood 

Before 
After 
Difference 

14.7 
21.6 

4.30 
3.63 
-0.67 

64 
63 
-1 

0.100 
0.128 
+0.028 

0.212 
0.296 
+0.084 

0.032 
0.040 
+0.008 

0.048 
0.060 
+0.012 

409 
409a 

May  29 

7.50 
7.50 

1 
1 

Ebb 
Ebb 

Before 
After 
Difference 

14.4 
21.6 

5.00 
4.70 
-0.30 

75 
80 
-5 

0.084 
0.100 
+0.016 

0.232 
0.332 
+0.100 

0.027 
0.028 
+0.001 

0.093 
0.042 
—0.051 

411 
411a 

May  29 

8.10 
8.10 

30 
30 

Ebb 
Ebb 

Before 
After 
Difference 

14.4 
21.6 

5.50 
4.60 
-0.90 

84 
80 
-4 

0.112 

0.180 

0.030 

0.080 

415 
415a 

June  11 

A.M. 
9.45 
9.45 

1 
1 

Ebb 
Ebb 

Before 
After 
Difference 

17.7 
17.8 

6 . 77 
1.85 
-1.92 

60 
30 
-30 

0.168 
0.076 
-0.092 

0.328 
0.332 
+0.004 

0.036 
0.046 
+0.010 

0.074 
0.124 
+0.050 

417 
417a 

June  11 

9.55 
9.55 

30 
30 

Ebb 
Ebb 

Before 
After 
Difference 

17.5 
17.7 

3.97 
1.80 
-2.17 

65 
29 
-36 

0.200 
0.140 
-0.060 

0.356 
0.356 
0.000 

0.038 
0.050 
+0.012 

0.092 
0.130 
+0.038 

430 
430a 

June  11 

P.  M. 
1.50 
1.50 

1 
1 

Flood 
Flood 

Before 
After 
Difference 

18.4 
18.4 

4.11 

2.08 
-2.03 

68 
34 
-34 

0.184 
0.124 
-0.060 

0.332 
0.332 
0.000 

0.040 
0.062 
+0.022 

0.070 
0.098 
+0.028 

432 
432a 

June  11 

2.00 
2.00 

30 
30 

Flood 
Flood 

Before 
After 
Difference 

17.2 
17.1 

4.72 
2.09 
-2.63 

77 
34 
-43 

0.244 
0.136 
-0.108 

0.320 
0.400 
+0.080 

0.040 
0.088 
+0.048 

0.040 
0.072 
+0.032 

3— ROBBINS  REEF,  NEAR  BELL  BUOY 


Latitude  40°  39'  15".    Longitude  74°  03'  50". 


1912 

P.  M. 

7 

Feb.  27 

1.15 

1 

Ebb 

Before 

2.8 

7.14 

87 

0.338 

0.298 

0.002 

0.188 

8 

1.25 

40 

Ebb 

Before 

2.8 

7.28 

89 

0.352 

0.326 

0.001 

0.219 

A.  M. 

13 

Mar.  4 

11.35 

1 

Ebb 

Before 

1.1 

7.14 

85 

0.192 

0.213 

0.001 

0.139 

14 

11.30 

40 

Ebb 

Before 

1.7 

7.14 

86 

0.196 

0.243 

0.001 

0.139 

23 

Mar.  5 

7.00 

1 

Flood 

Before 

0.6 

7.43 

88 

0.264 

0.406 

0.001 

0.179 

24 

7.05 

40 

Flood 

Before 

1.1 

7.43 

89 

0.364 

0.332 

0.001 

0.179 

P.  M. 

33 

Mar.  14 

12.30 

1 

Ebb 

Before 

3.3 

6.86 

80 

0.248 

0.180 

0.001 

0.209 

33a 

12.30 

1 

Ebb 

After 

21.1 

3.00 

49 

0.424 

0.002 

Difference 

-3.86 

-31 

+0.244 

+0.001 

34 

Mar.  14 

12.40 

40 

Ebb 

Before 

3.9 

6.86 

85 

0.292 

0.256 

0.001 

0.179 

34a 

12.40 

40 

Ebb 

After 

21.1 

3.00 

53 

0.268 

0.002 

Difference 

-3.86 

-32 

+0.012 

+0.001 

Mr 

CHEMICAL  ANALYSES  OF  HARBOR  WATER  751 
TABLE  CLXIV— Continued 


3 — ROBBINS  REEF,  NEAR  BELL  BUOY — Continued 


Sample 
No. 

Date 
1912 

Hour 
A.  M. 

Feet 
below 
surface 

Tidal 
current 

Incuba- 
tion 

Temp, 
water 
Deg.  C. 

Oxygen 

Parts  per  Million 

C.  C. 
per 
litre 

Per  cent, 
satura- 
tion 

Amu 

Albu- 
minoid 

aonia 
Free 

Nitrite 

Nitrate 

43 
43a 

April  3 

10.05 
10.05 

1 
1 

Flood 
Flood 

Before 
After 
Difference 

6.1 

18.3 

7.28 
4.17 
-3.11 

90 
66 
-24 

0.196 
0.152 
-0.044 

0.204 
0.228 
+0.024 

0.001 
0.001 
0.000 

0.179 
0.109 
-0.070 

44 
44a 

April  3 

10.15 
10.05 

40 
40 

Flood 
Flood 

Before 
After 
Difference 

6.1 
18.3 

7.00 
4.60 
-2.40 

90 
70 
-20 

0.200 
0.116 
-0.084 

0.140 
0.176 
+0.036 

0.001 
0.001 
0.000 

0.089 
0.089 
0.000 

53 
53a 

April  3 

P.  M. 
4.50 
4.50 

1 
1 

Ebb 
Ebb 

Before 
After 
Difference 

6.1 
20.0 

7.28 
3.33 
-3.95 

86 
52 
-34 

0.220 
0.184 
-0.036 

0.184 
0.204 
+0.020 

0.000 
0.001 
+0.001 

0.230 
0.089 
-0.141 

54 
54a 

April  3 

5.00 
5.00 

40 
40 

Ebb 
Ebb 

Before 
After 
Difference 

6.1 
20.0 

6.86 
3.24 
-3.62 

85 
53 
-32 

0.208 
0.168 
-0.040 

0.184 
0.192 
+0.008 

0.001 
0.001 
0.000 

0.109 
0.089 
-0.020 

65 
65a 

June  13 

A.M. 
11.15 
11.15 

1 
1 

Ebb 
Ebb 

Before 
After 
Difference 

17.2 
21.1 

4.19 
3.37 
-0.82 

70 
60 
-10 

0.264 
0.160 
-0.104 

0.144 

0.352 
+0.208 

0.002 
0.003 
+0.001 

0.038 
0.017 
-0.021 

66 
60a 

June  13 

11.20 
11.20 

40 
40 

Ebb 
Ebb 

Before 
After 
Difference 

16.7 
21.1 

4.19 

3.27 
-0.92 

69 
59 
-10 

0.192 
0.128 
-0.064 

0.036 
0.136 
+0.100 

0.001 
0.001 
0.000 

0.039 
0.030 
-0.009 

75 
75a 

June  13 

P.  M. 

3.40 
3.40 

1 
1 

Flood 
Flood 

Before 
After 
Difference 

17.2 
21.1 

4.29 
3.16 
-1.13 

71 
57 
-14 

0.168 
0.148 
—0.020 

0.132 
0.308 
+0.176 

0.002 
0.004 
+0.002 

0.028 
0.036 
+0.018 

76 
76a 

June  13 

3.45 
3.45 

40 
40 

Flood 
Flood 

Before 
After 
Difference 

16.7 
21.1 

4.29 
3.27 
-1.02 

71 
59 
-12 

0.162 
0.192 
+0.030 

0.100 
0.128 
+0.028 

0.002 
0.006 
+0.004 

0.028 
0.034 
+0.006 

85 
85a 

July  11 

A.M. 
10.10 
10.10 

1 
1 

Ebb 
Ebb 

Before 
After 
Difference 

23.9 
24.4 

3.00 
0.70 
-2.30 

57 
13 
-44 

0.344 
0.140 
-0.204 

0.384 
0.540 
+0.156 

0.003 
0.090 
+0.087 

0.070 
0.070 
0.000 

86 
86a 

July  11 

10.15 
10.15 

40 
40 

Ebb 
Ebb 

Before 
After 
Difference 

23.6 
24.4 

3.10 
0.80 
-2.30 

59 
15 
-44 

0.200 
0.108 
-0.092 

0.304 
0.420 
+0.116 

0.003 
0.051 
+0.048 

0.060 
0.000 
-0.060 

95 
95a 

July  11 

P.  M. 
2.30 
2.30 

1 
1 

Flood 
Flood 

Before 
After 
Difference 

23.9 
24.4 

3.50 
1.00 
-2.50 

67 
19 
-48 

0.256 
0^152 
-0.104 

0  464 
0.572 
+0.108 

0  003 
0.063 
+0.060 

0  087 
0.000 
-0.087 

96 
96a 

July  11 

2.35 
2.35 

40 
40 

Flood 
Flood 

Before 
After 
Difference 

23.6 
24.4 

3.50 
1.00 
-2.50 

67 
19 

-48 

0.224 
0.140 
-0.084 

0.348 
0.372 
+0.024 

0.002 
0.066 
+0.064 

0.058 
0.044 
-0.014 

105 
105a 

July  24 

A.M. 
10.35 
10.35 

1 
1 

Ebb 
Ebb 

Before 
After 
Difference 

21.7 
23.9 

2.90 
2.00 
-0.90 

53 
38 
-15 

0.244 
0.112 
-0.132 

0.492 
0.548 
+0.056 

0.054 
0.106 
+0.052 

0.026 
0.000 
-0.026 

106 
106a 

July  24 

10.40 
10.40 

40 
40 

Ebb 
Ebb 

Before 
After 
Difference 

21.7 

23.9 

2.90 
2.20 
-0.70 

53 
42 
-11 

0.152 
0.104 
-0.048 

0.380 
0.480 
+0.100 

0.054 
0.026 
-0.028 

0.056 
0.064 
+0.008 

752  DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

TABLE  CLXIV— Continued 


3— ROBBINS  REEF,  NEAR  BELL  BUOY— Continued 




Sample 
No. 

Date 
1912 

Hour 
P.  M. 

Feet 
below 
surface 

Tidal 
current 

Incuba- 
tion 

Temp, 
water 
Deg.  C. 

Oxygen 

Parts  per  Million 

per 
litre 

Per  cent, 
satura- 
tion 

Amm 

Albu- 
minoid 

onia 
Free 

Nitrite 

Nitrate 

115 
115a 

July  24 

2.50 
2.50 

1 
1 

Flood 
Flood 

Before 
After 
Difference 

21.7 
23.9 

o  c  a 

2.60 
-1.00 

65 
50 
-15 

0. 160 
0.096 
-0.064 

0.468 
0.504 
+0.036 

0.065 
0.070 
+0.005 

0.015 
0.000 
-0.015 

116 
116a 

July  24 

2.55 
2.55 

40 
40 

Flood 
Flood 

Before 
After 
Difference 

21.1 

23.9 

3.70 

o  c  a 

I .  oO 
-1.10 

67 
50 
-17 

0.156 
0.080 
-0.076 

0.244 
0.276 
+0.032 

0.039 
0.092 
+0.053 

0.011 
0.000 
-0.011 

317 
317a 

1913 
Jan.  9 

A.  M. 
8.23 
8.23 

1 
1 

Flood 
Flood 

Before 
After 
Difference 

2.8 
26.7 

£f  OA 

b .  60 
4.90 
-1.40 

72 

91 
+  19 

a  i  a  a 

0. 140 
0.120 
-0.020 

0. 136 
0.324 
+0.188 

0.012 
0.018 
+0.006 

0. 148 
0.112 
-0.036 

327 
327a 

Jan.  9 

P.  M. 
12.15 
12.15 

1 
1 

Ebb 
Ebb 

Before 
After 
Difference 

3.3 
3.3 

O.UU 

4.80 
+  1.20 

/u 
92 
+22 

a  i  a  a 
U .  144 

0.076 
-0.068 

A    1  C  A 

0. 164 
0.196 
+0.032 

0.016 
0.018 
+0.002 

0. 154 
0.192 
+0.038 

337 
337a 

Feb.  18 

A.M. 
11.10 
11.10 

1 
1 

Ebb 
Ebb 

Before 
After 
Difference 

1.7 
21.1 

5.90 
3.30 
-2.60 

68 
41 
-27 

0.172 
0.112 
-0.060 

0.160 
0.268 
+0.108 

0.026 
0.028 
+0.002 

0.094 
0.062 
-0.032 

338 
338a 

Feb.  18 

11.15 
11.15 

40 
40 

Ebb 
Ebb 

Before 
After 
Difference 

1.7 
21.1 

6.00 
3.40 
-2.60 

69 
61 

-8 

0.128 
0.120 
-0.008 

0.160 
0.320 
+0.160 

0.026 
0.024 
+0.002 

0.114 
0.136 
+0.022 

347 
347a 

Feb.  18 

P.  M. 
4.20 
4.20 

1 
1 

Flood 
Flood 

Before 
After 
Difference 

1.7 
21.1 

6.20 
4.00 

O  OA 

— 2.2U 

71 
70 
—  1 

0.140 
0.068 

— V.UiZ 

0.180 
0.200 
+0 . 020 

0.024 
0.022 

1  A  AAO 

+0. 002 

0.076 
0.078 

1  A  AAO 

+0.002 

348 
348a 

Feb.  18 

4.25 
4.25 

40 
40 

Flood 
Flood 

Before 
After 
Difference 

1.7 
21.1 

6.20 
4.00 
—2.20 

71 
70 
—  1 

0.140 

0.092 
—0.048 

0.172 
0.244 
+0.072 

0.024 
0.022 

A  AAO 

— 0.002 

0.166 
0.138 

A  AOO 

—0. 028 

391 
391a 

May  29 

12.22 
12.22 

1 
1 

Flood 
Flood 

Before 
After 
Difference 

15.0 
21.6 

4.60 
2.34 
-2.26 

73 
41 

-32 

0.152 
0.136 
-0.016 

0.336 
0.344 
+0.008 

0.034 
0.040 
+0.006 

0.066 
0.130 
+0.064 

393 
393a 

May  29 

1.05 
1.05 

40 
40 

Flood 
Flood 

Before 
After 
Difference 

14.4 
21.6 

6.00 
3.90 
-2.10 

95 
70 
-25 

0.140 
0.144 
+0.004 

0.228 
0.240 
+0.012 

0.024 
0.042 
+0.018 

0.066 
0.058 
-0.008 

406 
406a 

May  29 

6.45 
6.45 

1 
1 

Ebb 
Ebb 

Before 
After 
Difference 

15.0 
21.6 

5.00 
3.40 
-1.60 

78 
60 
-18 

0.084 
0.116 
+0.032 

0.308 
0.392 
+0.084 

0.040 
0.042 
+0.002 

0.050 
0.088 
+0.038 

408 
408a 

May  29 

7.15 
7.15 

40 
40 

Ebb 
Ebb 

Before 
After 
Difference 

14.4 
21.6 

5.10 
4.43 
-0.67 

78 
81 
+3 

0.112 
0.104 
-0.008 

0.240 
0.292 
+0.052 

0.029 
0.028 
-0.001 

0.050 
0.052 
+0.002 

418 
418a 

June  11 

A.M. 
10.30 
10.30 

1 
1 

Ebb 
Ebb 

Before 
After 
Difference 

17.7 
17.8 

4.37 
1.88 
-2.49 

71 
31 
-40 

0.192 
0.068 
-0.124 

0.384 
0.304 
-0.080 

0.040 
0.046 
+0.006 

0.070 
0.144 
+0.074 

420 
420a 

June  11 

10.50 
10.50 

40 
40 

Ebb 
Ebb 

Before 
After 
Difference 

18.5 
18.4 

5.58 
1.25 
-4.33 

93 
21 
-72 

0.176 
0.080 
-0.096 

0.336 
0.240 
-0.096 

0.036 
0.042 
+0.006 

0.064 
0.118 
+0.054 

433 
433a 

June  11 

P.  M. 
2.45 
2.45 

1 
1 

Flood 
Flood 

Before 
After 
Difference 

17.8 
17.8 

5.26 
2.63 
-2.63 

89 
44 
-45 

0.164 
0.124 
-0.040 

0.244 
0.380 
+0.136 

0.024 
0.044 
+0.020 

0.036 
0.094 
+0.058 

CHEMICAL  ANALYSES  OF  HARBOR  WATER  753 
TABLE  CLXIV— Continued 


3— ROBBINS  REEF,  NEAR  BELL  BUOY— Continued 


Oxygen 

Parts  per  Million 

Sample 
No. 

Date 
1913 

Hour 
P.  M. 

Feet 
below 
surface 

Tidal 
current 

Incuba- 
tion 

Temp, 
water 
Deg.  C. 

C.  C. 
per 
litre 

Per  cent, 
satura- 
tion 

Ammonia 

Nitrite 

Nitrate 

Albu- 
minoid 

Free 

435 
435a 

June  11 

3.00 
3.00 

40 
40 

Flood 
Flood 

Before 
After 
Difference 

17.2 
17.1 

5.83 
3.94 
-1.89 

98 
60 
-38 

0.148 
0.092 
-0.056 

0.192 
0.360 
+0.168 

0.024 
0.040 
+0.016 

0.046 
0.030 
-0.016 

4— KILL  VAN  KULL, 

MIDSTREAM,  OFF  SAILORS  SNUG  HARBOR 

Latitude  40°  38'  50*. 

Longitude  74°  06'  07'. 

15 
16 

1912 
Mar.  4 

Noon 
12.00 
P.  M. 
12.05 

1 

30 

Ebb 
Ebb 

Before 
Before 

1.1 
1.7 

7.14 
7.14 

83 
84 

0.376 
0.276 

0.444 
0.396 

0.001 
0.001 

0.269 
0.289 

25 
26 

35 
35a 

Mar.  5 
Mar.  14 

A.M. 
7.30 
7.35 

P  M 

X  .  1V1 . 

1.10 
1.10 

1 

30 

1 
1 

Flood 
Flood 

Ebb 
Ebb 

Before 
Before 

Before 
After 
Difference 

0.6 
1.1 

5.0 
21.1 

7.14 
7.14 

7.00 
2  86 
-4.14 

84 

85 

82 
46 
-36 

0.316 
0.182 

0.524 

0.432 
0.176 

0.896 
1.044 
+0.148 

0.001 
0.001 

0.002 
0.003 
+0.001 

0.289 
0.219 

0.468 

oo 
36a 

iVi            i  A 

1  9ft 

1.20 

35 

HilJU 

Ebb 

Koff\ro 

After 
Difference 

5.0 
21.1 

6.86 
2.57 
—4.29 

85 
18 
-67 

0.416 

0.660 
0.096 
+0.300 

fl  flfll 
0.003 
+0.002 

fl  3ftQ 

45 
45a 

April  3 

A.  M. 
10.30 
10.30 

1 
1 

Flood 
Flood 

Before 
After 
Difference 

6.1 
18.3 

7.00 
4.44 

o  eft 
—  4.00 

87 
70 

—  1  / 

0.212 
0.144 

— U . U08 

0.148 
0.204 
-t-u .  uoo 

0.001 
0.001 
0.000 

0.129 
0.079 
-0.050 

46 
46a 

April  3 

10.40 
10.40 

35 
35 

Flood 
Flood 

Before 
After 
Difference 

6.1 
18.3 

6.86 
4.60 
-2.26 

87 
76 
-11 

0.212 
0.116 
-0.096 

0.124 
0.168 
+0.044 

n  ftfti 
0.001 
0.000 

ft  ft9Q 

0.069 
+0.040 

51 

5lA 

April  3 

P.M. 
4.30 
4.30 

1 
1 

Ebb 
Ebb 

Before 
After 
Difference 

6.1 
18.3 

7.28 
4.31 
-2.97 

86 
67 
-19 

0.216 
0.176 
-0.040 

0.288 
0.300 
+0.012 

0.002 
0.002 
0.000 

0.148 
0.148 
0.000 

52 
52a 

April  3 

4.40 
4.40 

35 
35 

Ebb 
Ebb 

Before 
After 
Difference 

6.1 
18.3 

7.00 
4.06 
-2.94 

85 
64 
-21 

0.268 
0.204 
-0.064 

0.264 
0.292 
+0.028 

0.002 
0.000 

U.  ^±25 

0.078 
-0.170 

67 
67a 

June  13 

A.  M. 
11.30 
11.30 

1 
1 

Ebb 
Ebb 

Before 
After 
Difference 

17.2 
21.1 

4.29 
3.27 
-1.02 

70 
57 
-13 

0.380 
0.224 
-0.156 

0.032 
0.372 
+0.340 

0.004 
0.004 
0.000 

0.046 
0.036 
-0.010 

68 
68a 

June  13 

11.35 
11.35 

35 
35 

Ebb 
Ebb 

Before 
After 
Difference 

17.2 
21.1 

4.29 
3.37 
-0.92 

70 
60 
-10 

0.350 
0.144 
-0.206 

0.048 
0.292 
+0.244 

0.003 
0.008 
+0.005 

0.047 
0.052 
+0.005 

73 
73a 

June  13 

P.  M. 
3.10 
3.10 

1 
1 

Flood 
Flood 

Before 
After 
Difference 

17.2 
21.1 

4.39 
2.96 
-1.43 

73 
52 
-21 

0.152 
0.120 
-0.032 

0.100 
0.300 
+0.200 

0.002 
0.004 
+0.002 

0.028 
0.026 
-0.002 

74 
74a 

June  13 

3.15 
3.15 

40 
40 

Flood 
Flood 

Before 
After 
Difference 

16.7 
21.1 

4.39 
3.06 
-1.33 

71 
54 
-17 

0.212 
0.144 
-0.068 

0.120 
0.292 
+0.172 

0.002 
0.008 
+0.006 

0.068 
0.052 
-0.016 

754  DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

TABLE  CLXIV— Continued 


4— KILL  VAN  KULL,  MIDSTREAM,  OFF  SAILORS  SNUG  HARBOR— Continued 


Oxygen 

Parts  per  Million 

Sample 
No. 

Date 
1912 

TT  

Hour 
A.  M. 

Feet 
below 
surface 

lidal 
current 

Incuba- 
tion 

Temp. 

WO  i  AT* 

Deg.  C. 

C.  C. 
per 

Per  cent, 
satura- 

Ammonia 

Nitrite 

Nitrate 

litre 

tion 

Albu- 

in  mom 

Free 

87 

July  11 

10.30 

1 

Ebb 

Before 

23.9 

3.10 

58 

0.388 

0.376 

0.005 

0.075 

87a 

10.30 

1 

Ebb 

After 

24.4 

0.80 

15 

o  fi4f> 

0.088 

0.000 

T)i  rfprpn  pp- 

-2.30 

—43 

-0.172 

+0.264 

+0.083 

-0.075 

88 

July  11 

10.40 

35 

Ebb 

Before 

23.9 

3. 10 

58 

0.372 

0.412 

0.006 

0.074 

88a 

10.40 

35 

Ebb 

After 

24.4 

0.80 

15 

O  1Q9 

n  40R 

0.255 

0.005 

Difference 

—2.30 

-43 

-0.180 

+0.084 

+0.249 

-0.069 

P.  M. 

93 

July  11 

2.00 

1 

Flood 

Before 

23.9 

3.20 

61 

0.308 

0.400 

0.003 

0.077 

93a 

2.00 

1 

Flood 

After 

24.4 

1.00 

19 

n  lis 

O  4fi0 

0.066 

0.000 

T)i  fr  pfpti  pp 

J— '111  Cl  CllLiC 

-2.20 

-42 

-0.190 

+0.060 

+0.063 

-0.077 

94 

July  11 

2.05 

35 

Flood 

Before 

23.9 

3.20 

61 

0.268 

0.428 

0.003 

0.087 

94a 

2.05 

35 

Flood 

After 

24.4 

0.90 

17 

n  i  fin 

f)  484 

0.133 

0.017 

Difference 

-2.30 

-44 

-0.108 

+0.056 

+0.130 

-0.070 

A.M. 

107 

July  27 

11.15 

1 

Ebb 

Before 

21.7 

3.40 

61 

0.308 

0.420 

0.190 

0.000 

107a 

11.15 

1 

Ebb 

After 

23.9 

2.60 

49 

0  984 

0.056 

0.094 

T)  i  tt  orpn  pp 

-0.80 

—  12 

—0.014 

+0.096 

-0. 134 

-0.094 

108 

July  24 

11.20 

35 

Ebb 

Before 

21.7 

3.30 

60 

0.288 

0.416 

0. 190 

0.000 

108a 

11.20 

35 

Ebb 

After 

23.9 

2.60 

49 

0.204 

0.572 

0.120 

0.010 

Difference 

-0.70 

-11 

—  fi  074. 

4-ft  1  ^fi 

-0.070 

+0.010 

P.  M. 

113 

July  24 

2.25 

1 

Flood 

Before 

21.7 

3.80 

69 

0.196 

0.488 

0.099 

0.021 

113a 

2.25 

1 

Flood 

After 

23.9 

2.50 

47 

0.144 

0.508 

0.086 

0.014 

Difference 

-1.30 

-22 

-0.013 

-0.007 

114 

July  24 

2.30 

35 

Flood 

Before 

21.7 

3.80 

fiQ 

0.140 

0.452 

0.061 

O  000 

114a 

2.30 

35 

Flood 

After 

23.9 

2.60 

50 

0.096 

0.416 

0.060 

0.000 

Difference 

—  1.20 

-19 

 n  n44 

—  O  03fi 

-0.001 

0.000 

1Q1  "i 

A  M 

/it .  iVJ.  . 

319 

Jan.  9 

8.40 

1 

Flood 

Before 

2.8 

6.10 

70 

0.128 

0.180 

0.014 

0.206 

319a 

8.40 

1 

Flood 

After 

26.7 

4.90 

91 

0.124 

0.192 

0.018 

0.112 

Difference 

-1.20 

+21 

— n  nr>4 

-4-0  019 

+0.004 

-0.094 

P.  M. 

329 

Jan.  9 

12.40 

1 

Ebb 

Before 

3.3 

6.00 

70 

0.200 

0.228 

0.022 

0.208 

329a 

12.40 

1 

Ebb 

After 

26.7 

4.60 

94 

0.124 

0.340 

0.032 

0.178 

Difference 

—1.40 

+24 

— 0.076 

+0. 112 

+0.010 

—0.030 

A.M. 

339 

Feb.  18 

11.30 

1 

Ebb 

Before 

1.7 

5.80 

65 

0.228 

0.488 

0.042 

0.148 

339a 

11.30 

1 

Ebb 

After 

21.1 

3.40 

60 

0.196 

0.628 

0.042 

0.128 

Difference 

-2.40 

-5 

-0.032 

+0.140 

0.000 

-0.020 

340 

Feb.  18 

11.35 

3.5 

Ebb 

Before 

1.7 

5.80 

65 

0.268 

0.440 

0.042 

0.198 

340a 

11.35 

35 

Ebb 

After 

21.1 

3.00 

53 

0.196 

0.608 

0.040 

0.140 

Difference 

-2.80 

-12 

-0.072 

+0.168 

-0.002 

-0.058 

P.  M. 

345 

Feb.  18 

4.06 

1 

Flood 

Before 

1.7 

6.20 

71 

0.160 

0.176 

0.024 

0.176 

345a 

4.06 

1 

Flood 

After 

21.1 

3.60 

65 

0.112 

0.232 

0.024 

0.156 

Difference 

-2.60 

-6 

-0.048 

+0.056 

0.000 

-0.020 

346 

Feb.  18 

4.05 

35 

Flood 

Before 

1.7 

6.30 

72 

0.184 

0.184 

0.026 

0.194 

346a 

4.05 

35 

Flood 

After 

21.1 

4.20 

75 

0.132 

0.252 

0.020 

0.150 

Difference 

-2.10 

+3 

-0.052 

+0.068 

-0.006 

-0.044 

CHEMICAL  ANALYSES  OF  HARBOR  WATER  755 
TABLE  CLXIV— Continued 


4— KILL  VAN  KULL,  MIDSTREAM,  OFF  SAILORS  SNUG  HARBOR— Continued 


Sample 
No. 

Date 
1913 

Hour 
A.  M. 

Feet 
below 
surface 

Tidal 
current 

Incuba- 
tion 

Temp, 
water 
Deg.  C. 

Oxygen 

Parts  per  Million 

C.  C. 
per 
litre 

Per  cent, 
satura- 
tion 

Amu 
minoid 

onia 
Free 

Nitrite 

Nitrate 

388 
388a 

May  29 

11.40 
11.40 

1 
1 

Flood 
Flood 

Before 
After 
Difference 

15.6 
21.6 

i.  on 
1.80 
-2.10 

fil 
Dl 

31 
-30 

O  AQA 

U .  1UD 

390 
390a 

May  29 

Noon 
12.00 
12.00 

35 
35 

Flood 
Flood 

Before 
After 
Difference 

15.0 
21.6 

4  OO 

<± .  yu 

2.70 
-2.20 

77 

47 
-30 

n  OAA 

n  a io 

n  c\aa 

403 
403a 

May  29 

P.  M. 
5.55 
5.55 

1 
1 

Ebb 
Ebb 

Before 
After 
Difference 

15.0 
21.6 

5.10 
4.11 
-0.99 

86 
73 
-13 

0.144 
0.188 
+0.044 

0.364 
0.512 
+0.148 

0.044 
0.060 
+0.016 

0.046 
0.100 
+0.054 

405 
405a 

May  29 

6.15 
6.15 

35 
35 

Ebb 
Ebb 

Before 
After 
Difference 

15.0 
21.6 

0  .  /  u 

5.26 
-0.44 

on 

93 
+3 

0.152 
+0.004 

U  .  O-iXJ 

0.496 
+0.156 

U .  U-4U 

0.054 
+0.014 

U .  \JOV 

0.106 
+0.056 

421 
421a 

June  11 

A.M. 
11.05 
11.05 

1 
1 

Flood 

Flood 

Before 
After 
Difference 

17.7 
17.8 

4.39 
2.37 
—2.02 

73 
39 
—34 

0.160 
0.092 
—0.068 

0.324 
0.360 
+0.036 

0.036 
0.036 
0.000 

0.084 
0.124 
+0.040 

423a 

June  11 

11.20 

35 

Jf  looa 
Flood 

Before 
After 
Difference 

18 .  O 

18.4 

3.92 
2.33 
-1.59 

66 
38 
-28 

0.180 
0.080 
-0.100 

0.296 
0.268 
-0.028 

0.036 
0.070 
+0.034 

0.084 
0.090 
+0.006 

436 
436a 

June  11 

P.  M. 
3.30 
3.30 

1 
1 

Ebb 
Ebb 

Before 
After 
Difference 

18.4 
18.4 

4.61 
2.92 
-1.69 

78 
49 
-29 

0.160 
0.100 
-0.060 

0.324 
0.352 
+0.028 

0.040 
0.060 
+0.020 

0.090 
0.090 
0.000 

438 
438a 

June  11 

3.45 
3.45 

30 
30 

Ebb 
Ebb 

Before 
After 
Difference 

17.2 
17.1 

4.33 
3.56 
-0.77 

72 
59 
-13 

0.104 

0.096 
-0.008 

0.223 
0.356 
+0.128 

0.028 
0.062 
+0.034 

0.102 
0.088 
-0.014 

6 — NARROWS,  BETWEEN  FORTS  LAFAYETTE  AND  WADS  WORTH 


Latitude  40°  36'  25'.    Longitude  74°  02'  48". 


1912 

P.  M. 

5 

Feb.  27 

12.30 

1 

Ebb 

Before 

2.8 

7.57 

92 

0.364 

0.290 

0.001 

0.190 

6 

12.40 

60 

Flood 

Before 

3.3 

7.71 

98 

0.346 

0.134 

0.001 

0.149 

17 

Mar.  4 

1.00 

1 

Ebb 

Before 

1.1 

7.43 

88 

0.219 

0.223 

0.001 

0.179 

18 

1.05 

60 

Ebb 

Before 

1.7 

7.43 

88 

0.216 

0.223 

0.001 

0.129 

A.M. 

27 

Mar.  5 

8.10 

1 

Flood 

Before 

0.6 

8.15 

96 

0.230 

0.300 

0.001 

0.119 

28 

8.15 

60 

Flood 

Before 

1.1 

8.00 

97 

0.250 

0.272 

0.001 

0.119 

P.M. 

37 

Mar.  14 

1.50 

1 

Ebb 

Before 

3.9 

7.43 

88 

0.404 

0.268 

0.001 

0.239 

37a 

1.50 

1 

Ebb 

After 

21.1 

3.43 

57 

0.416 

0.002 

Difference 

-4.00 

-31 

+0.148 

+0.001 

38 

Mar.  14 

2.00 

60 

Flood 

Before 

3.9 

7.57 

95 

0.276 

0.172 

0.000 

0.100 

38a 

2.00 

60 

Flood 

After 

21.1 

4.00 

71 

0.176 

0.002 

Difference 

-3.57 

-24 

+0.004 

+0.002 

756  DATA  RELATING  TO  THE  PROTECTION  OF  THE  HARBOR 

TABLE  CLXIV— Continued 


6— NARROWS,  BETWEEN  FORTS  LAFAYETTE  AND  WADS  WORTH— Continued 


Oxygen 

Parts  per  Million 

»■-_>  lX  HI  LI  1 C 

No. 

Date 

Hour 
A.  M. 

Feet 
below 

Tidal 

X  1  1  V.  Li  L/C* 

tion 

Temp, 
water 

C.  C. 

Per  cent. 

Ammonia 

1912 

surface 

P11TTPT1  I 

Deg.  C. 

per 
litre 

satura- 
tion 

Albu- 
minoid 

Free 

Nitrite 

Nitrate 

47 

April  3 

11.00 

1 

Flood 

Before 

6.1 

7.71 

97 

0.204 

0.156 

0.001 

0.139 

47a 

11.00 

1 

Flood 

After 

18.3 

4.86 

78 

0.136 

0.164 

0.001 

0.069 

Lyill  Vi  LyLlL/L* 

-2.85 

-19 

-0.068 

-f-0.008 

0.000 

-0.070 

48 

April  3 

11.10 

60 

Flood 

Before 

6.1 

7.57 

0.200 

0.156 

0.001 

0.109 

48a 

11.10 

60 

Flood 

After 

18.3 

4.87 

81 

0.160 

0.148 

0.001 

0.069 

Difference 

-2.70 

-17 

-0.040 

-0.008 

0.000 

-0.040 

P.  M. 

49 

April  3 

3.50 

1 

Ebb 

Before 

6.1 

7.43 

ss 

0.192 

0.216 

0.000 

0.150 

49a 

3.50 

1 

Ebb 

After 

18.3 

4. 17 

63 

0.108 

0.192 

0.001 

0. 149 

Difference 

-3.26 

-25 

-0.084 

-0.024 

+0.001 

-0.001 

50 

April  3 

4.00 

60 

Ebb 

Before 

6.1 

7.14 

87 

yj .  i\)it 

0.001 

0.239 

50a 

4.00 

60 

Ebb 

After 

18.3 

4.06 

64 

0.104 

0.184 

0.001 

0.129 

Difference 

—  3.08 

—23 

+0.104 

+0.020 

0.000 

—0. 110 

A.  M. 

69 

June  13 

11.55 

1 

Ebb 

Before 

17.2 

4.29 

71 

0.192 

o.oso 

0.002 

0.029 

69a 

11.55 

1 

Ebb 

After 

21.1 

3.47 

62 

0.152 

0.284 

0.002 

0.019 

Difference 

-0.82 

-9 

-0.040 

+0.204 

0.000 

-0.010 

Noon 

70 

June  13 

12.00 

60 

Ebb 

Before 

16.7 

4.39 

73 

0.236 

0.076 

0.002 

0.038 

70a 

12.00 

60 

Ebb 

After 

21.1 

3.57 

64 

0.128 

0.280 

0.003 

0.037 

Difference 

-0.82 

-9 

-0.108 

+0.204 

+0.001 

-0.001 

P.  M. 

71 

June  13 

2.30 

1 

Flood 

Before 

17.2 

4.80 

80 

0.208 

0.136 

0.002 

0.048 

71a 

2.30 

1 

Flood 

After 

21.1 

3.58 

68 

0.136 

0.332 

0.003 

0.047 

T~)i  ff  prpn^p 

-1.22 

-12 

-0.072 

+0.196 

+0.001 

-0.001 

72 

June  13 

2.35 

60 

Flood 

Before 

16.7 

4.90 

81 

0.296 

0.100 

0.002 

0.028 

72a 

2.35 

60 

Flood 

After 

21.1 

3.68 

66 

0.128 

0.224 

a  nr\A 

0.004 

U.UUo 

Difference 

-1.22 

-15 

-0.168 

+0.124 

+0.002 

-0.022 

A.M. 

89 

July  11 

11.15 

1 

Ebb 

Before 

23.9 

O  OA 

3 . 20 

01 

0.284 

0.340 

A  AAO 

U.UUo 

U.U/ / 

89a 

11.15 

1 

Ebb 

After 

24.4 

1.00 

19 

0.132 

0.412 

0.094 

0.000 

Difference 

-2.20 

-42 

-0.152 

+0.072 

+0.091 

-0.077 

90 

July  11 

11.25 

60 

Ebb 

Before 



23.6 

3.30 

63 

0.228 

0.356 

0.003 

0.047 

90a 

11.25 

60 

Ebb 

After 

24.4 

i  aa 
1 .00 

1  A 

19 

0.120 

0.400 

A    AO  C 

U.Uoo 

A  AAA 
U  .  UUU 

Difference 

-2.30 

-44 

-0.108 

+0.044 

+0.032 

-0.047 

P.  M. 

91 

July  11 

1.30 

1 

Flood 

Before 

23.9 

o  aa 
6 . 90 

75 

0.348 

0.232 

A  AAO 

U.UUo 

A    (\A  1 

U.U4/ 

9lA 

1.30 

1 

Flood 

After 

24.4 

1.80 

35 

0.148 

0.436 

0.064 

0.006 

OifT  prenr,e 

-2.10 

-40 

-0.200 

+0.204 

+0.061 

-0.041 

92 

July  11 

1.35 

60 

Flood 

Before 

23.6 

4.00 

77 

0.236 

0.308 

0.003 

0.087 

92a 

1.35 

60 

Flood 

After 

24.4 

1.80 

35 

0.124 

0.380 

0.051 

0.000 

Difference 

-2.20 

-42 

-0.112 

+0.072 

+0.048 

-0.087 

A.M. 

109 

July  24 

11.45 

1 

Ebb 

Before 

21.7 

3.40 

62 

0.160 

0.452 

0.054 

0.026 

109a 

11.45 

1 

Ebb 

After 

23.9 

2.20 

42 

0.152 

0.500 

0.066 

0.034 

Difference 

-1.20 

-20 

-0.008 

+0.048 

+0.012 

-0.008 

110 

July  24 

11.50 

60 

Ebb 

Before 

21.7 

3.40 

62 

0.188 

0.388 

0.070 

0.000 

110a 

11.50 

60 

Ebb 

After 

23.9 

2.40 

46 

0.120 

0.496 

0.020 

0.120 

Difference 

-1.00 

-16 

-0.068 

+0.108 

-0.050 

+0.120 

P.  M. 

111 

July  24 

1.50 

1 

Flood 

Before 

21.7 

3.90 

71 

0.244 

0.456 

0.056 

0.064 

111a 

1.50 

1 

Flood 

After 

23.9 

2.40 

46 

0.096 

0.420 

0.050 

0.020 

Difference 

-1.50 

-25 

-0.148 

-0.036 

-0.006 

-0.044 

CHEMICAL  ANALYSES  OF  HARBOR  WATER  757 
TABLE  CLXIV— Continued 


6 — NARROWS,  BETWEEN  FORTS  LAFAYETTE  AND  WADSWORTH — Continued 


Sample 
No. 

Date 
1912 

Hour 
A.  M. 

Feet 
below 
surface 

Tidal 
current 

Incuba- 
tion 

Temp, 
water 
Deg.  C. 

Oxygen 

Parts  per  Million 

C.  C. 
per 
utre 

Per  cent, 
satura- 
tion 

Amn 

A1DU- 

minoid 

lonia 
Free 

Nitrite 

Nitrate 

112 
112  a 

July  24 

1.55 
1.55 

60 
60 

Flood 
Flood 

Before 
After 
Difference 

21.1 

23.9 

4.00 
2.60 

1  A(\ 

—  1 .41) 

73 
50 

— Zo 

0.148 

0.096 
 a  n^o 

0.400 
0.520 

0.052 
0.072 
-f-U.  uzu 

0.078 
0.058 

A  AOA 

— Vj  .  \JZ\J 

321 
321a 

1913 
Jan.  9 

A.  M. 
9.06 
9.06 

1 
1 

Flood 
Flood 

Before 
After 
Difference 

3.9 
26.7 

6.80 
5.10 

1  1C\ 

82 
96 

1    1  A 

+•14 

0.144 
0.100 

0.144 
0.204 

0.012 
0.024 

i  n  ni  o 
tU  .  yjiz 

0.208 
0.166 

A  f\AO 

331 
331a 

Jan.  9 

P.  M. 
1.30 
1.30 

1 
1 

Ebb 
Ebb 

Before 
After 
Difference 

3.3 
26.7 

6.10 
^  in 

-1.00 

71 

QA 

yo 
+25 

0.148 

n  H7A 

-0.072 

0.148 

U  .  1  / 

+0.024 

0.020 
0.000 

0.160 

U  .  -  -±U 

+0.080 

341 
341a 

Feb.  18 

Noon 
12.00 
12.00 

1 
1 

Ebb 
Ebb 

Before 
After 
Difference 

1.7 
21.1 

A  f\f\ 

O .  UU 

3.80 
-2.20 

AO 

68 
-1 

n  i  A-(\ 
0.112 
-0.028 

0.256 
+0.028 

0.032 
+0.004 

A  1 0O 

0.108 
-0.014 

342 
342a 

Feb.  18 

P.  M. 

12.05 
12.05 

60 
60 

Ebb 
Ebb 

Before 
After 
Difference 

1.7 
21.1 

A  1 A 
0 .  1U 

4.00 
-2.10 

72 
+2 

fi   1  OA 

0.108 
+0.016 

U.  Li  Z 

0.268 
+0.096 

A  AOQ 

0.034 
+0.006 

A   1 0O 

u.  iyj 
0.176 
-0.016 

343 
343a 

Feb.  18 

3.25 
3.25 

1 
1 

Flood 
Flood 

Before 
After 
Difference 

1.7 
21.1 

a  aa 
O .  O  il 

4.80 
-1.80 

7A 

86 
+10 

a  i  no 
U .  1U8 

0.104 

-0.004 

(\   1  OA 

u.  iyo 
0.236 
+0.040 

u.uzo 
0.024 
-0.002 

A   1 0A 

0. 1»4 

0.126 
-0.068 

344 
344a 

Feb.  18 

3.30 
3.30 

60 
60 

Flood 
Flood 

Before 
After 
Difference 

1.7 
21.1 

6.70 
-1.90 

78 

07 
Oi 

+9 

0.164 

a  1 1  a 
U.  110 

-0.048 

0.212 

A  OQft 

U .  _ob 
+0.024 

0.028 

A  f\OA 

U.U/4 

-0.004 

0.182 

A    1  OA 
U.  ISO 

+0.004 

385 
385a 

May  29 

A.  M. 
10.05 
10.05 

1 
1 

Ebb 
Ebb 

Before 
After 
Difference 

15.6 
21.6 

A  AC\ 

4.4U 

2.57 
-1.83 

AO 
DO 

40 
-28 

U.  ll Z 

0.116 
-0.056 

U.o40 

0.324 
-0.016 

0.029 
0.038 
+0.009 

A    AO  % 

0.081 
0.042 
-0.039 

387 
387a 

May  29 

10.30 
10.30 

60 
60 

Ebb 
Ebb 

Before 
After 
Difference 

14.4 
21.6 

C    A  A 

0 .  oU 
4.41 
-1.19 

91 

79 
-12 

0. 124 
0.092 
-0.032 

0.216 
0.220 
+0.004 

0.020 
0.026 
+0.006 

A  /\OA 

0.030 
0.054 
+0.024 

400 
400a 

May  29 

P.  M. 

4.45 
4.45 

11 
11 

Flood 
Flood 

Before 
After 
Difference 

15.0 
21 .6 

5.20 
4.30 
-0.90 

84 
77 
-7 

0.100 
0.116 
+0.016 

0.236 
0.324 
+0.088 

0.020 
0.038 
+0.018 

0.060 
0.042 
-0.018 

402 
402a 

May  29 

5.10 
5.10 

60 
60 

Flood 
Flood 

Before 
After 
Difference 

14.4 
21.6 

0 . 91) 

3.81 
-2.09 

94 
71 

-23 

0.080 
0.092 
+0.012 

0.212 
0.220 
+0.008 

0.040 
0.226 
+0.014 

0.000 
0.054 
+0.054 

424 
424a 

June  11 

12.05 
12.05 

1 
1 

Flood 
Flood 

Before 
After 
Difference 

18.5 
18.4 

A  11 

4.11 

2.79 
-1.34 

■?a 

47 

-23 

U.  I/O 

0.088 
-0.088 

0.268 
0.232 
-0.036 

0.030 
0.032 
+0.002 

A  f\rin 

0.090 
0.138 
-0.048 

426 
426a 

June  11 

12.15 
12.15 

60 
60 

Flood 
Flood 

Before 
After 
Difference 

16.8 
16.7 

4.15 
3.03 
-1.12 

67 
50 
-17 

0.144 
0.092 
-0.052 

0.208 
0.320 
+0.112 

0.024 
0.032 
+0.008 

0.086 
0.058 
-0.028 

439 
439a 

June  11 

4.20 
4.20 

1 
1 

Ebb 
Ebb 

Before 
After 
Difference 

18.0 
17.8 

5.66 
3.36 
-2.30 

96 
77 
-19 

0.132 
0.072 
-0.060 

0.228 
0.284 
+0.056 

0.026 
0.024 
-0.002 

0.084 
0.036 
-0.048 

441 
441a 

June  11 

4.35 
4.35 

60 
60 

Ebb 
Ebb 

Before 
After 
Difference 

16.7 
16.9 

6.07 
3.23 
-2.84 

102 
54 
-48 

0.108 
0.064 
+0.044 

0.188 
0.280 
+0.092 

0.020 
0.044 
+0.024 

0.090 
0.046 
-0.044 

ORGANIZATION  AND  FORCE  EMPLOYED 


The  work  of  the  Commission  has  been  deliberative  and  executive.  The  deliberative 
work  has  been  carried  on  at  meetings  of  the  board,  of  which  there  has  usually  been 
one  each  week  throughout  the  year.  The  executive  work  has  been  done  chiefly  through 
a  staff  of  trained  assistants,  acting  under  the  personal  direction  of  the  President.  The 
direction  of  the  scientific  and  technical  work  by  the  President  has  made  it  unnecessary 
to  employ  a  Chief  Engineer,  Chief  Chemist  or  Chief  Bacteriologist,  and  has  made  it 
possible  for  the  members  of  the  Commission  to  keep  in  immediate  contact  with  every 
detail  of  the  investigation.  To  the  ability,  loyalty  and  industry  of  the  staff  is  to  be 
ascribed  a  large  part  of  the  results  arrived  at. 

Over  twenty  experts  have  been  consulted  by  the  Commission  and  the  reports  which 
they  have  rendered  have  contributed  materially  to  place  the  work  upon  a  broad  and 
authoritative  basis. 

Acknowledgment  is  made  of  assistance  and  co-operation  from  the  United  States 
Government,  especially  the  U.  S.  Coast  and  Geodetic  Survey  and  the  Corps  of  En- 
gineers of  the  U.  S.  Army.  The  New  York  City  officers,  particularly  the  engineers  of 
the  bureaus  of  sewers,  have  furnished  the  Commission  with  much  valuable  data  and 
criticism. 

The  assistants  employed  between  January,  1908,  when  the  Commission  was  reor- 
ganized, and  May,  1914,  have  been  as  follows: 


Names. 


Kenneth  Allen  

D.  S.  Merritt  

Wm.  B.  Fuller  

John  H.  Gregory  

David  Loewensohn . . 

W.  W.  DeBerard  

J.  E.  Hill  

Geo.  H.  Shaw  

Donald  Belcher  

Charles  A.  Holden . . . 

Robert  B.  Morse  

Ernest  F.  Robinson . . 

Sidney  Smith  

Herbert  W.  Harvey . . 

P.  F.  McClellan  

Harold  A.  Brown  

R.  M.  Merriman  

Homer  N.  Calver  

John  P.  Fox.  

George  Perrine  

William  R.  Copeland 

David  Morey  

Payn  B.  Parsons  

Raymond  H.  Pond . . 

R.  N.  Hoyt  

Max  L.  Berrey  

S.  R.  Keif  

A.  G.  Coonan  

Harriet  Gellert  

Florence  M.  Dolan. . 


Title  under  Civil  Service 
Classifications. 


Engineer  

Engineer  

Engineer  

Engineer  

Engineer  

Assistant  Engineer  

Assistant  Engineer  

Assistant  Engineer  

Assistant  Engineer  

Assistant  Engineer  

Assistant  Engineer  

Assistant  Engineer  

Assistant  Engineer  

Assistant  Engineer  

Engineering  Assistant . . 
Engineering  Assistant . . 
Engineering  Assistant . . 
Hydrographic  Assistant 

Statistician  

Statistician  

Chemist  

Chemist  

Bacteriologist  

Biologist  

Biologist  

Draughtsman  

Stenographer  

Stenographer  

Stenographer  

Stenographer  


Period  of  Service. 


Beginning. 

Ending. 

July 

27, 

1908 

April 

30, 

1914 

Nov. 

18, 

1908 

Jan. 

15, 

1910 

Feb. 

4, 

1909 

June 

12, 

1909 

Sept. 

20, 

1910 

June 

15, 

1911 

Feb. 

18, 

1913 

April 

18, 

1913 

Sept. 

20, 

1909 

Mch. 

31, 

1910 

Aug. 

10, 

1908 

Oct. 

9, 

1908 

Sept. 

1, 

1909 

April 

14, 

1910 

July 

29, 

1910 

May 

10, 

1911 

Aug. 

20, 

1910 

Aug. 

10, 

1912 

Oct. 

24, 

1910 

May 

31, 

1912 

Dec. 

3, 

1912 

April 

30, 

1914 

Dec. 

4, 

1912 

April 

15, 

1913 

Mch. 

1, 

1913 

April 

30, 

1914 

Nov. 

27, 

1909 

April 

30, 

1910 

Nov. 

27, 

1909 

Jan. 

15, 

1910 

Nov. 

17, 

1909 

Nov. 

18, 

1909 

June 

12, 

1913 

Aug. 

31, 

1913 

May 

28, 

1908 

Dec. 

12, 

1909 

Feb. 

1, 

1910 

Mch. 

3, 

1910 

Oct. 

1, 

1911 

Feb. 

14, 

1914 

Aug. 

24, 

1909 

Nov. 

27, 

1909 

Mch. 

1, 

1909 

April 

30, 

1910 

May 

10, 

1911 

May 

16, 

1913 

Aug. 

17, 

1908 

July 

31, 

1909 

June 

20, 

1909 

Jan. 

12, 

1910 

Feb. 

23, 

1909 

April 

30, 

1914 

July 

27, 

1908 

April 

30, 

1910 

June 

13, 

1910 

April 

30, 

1914 

June 

15, 

1913 

Nov. 

8, 

1913 

Dec. 

1, 

1913 

April 

30, 

1914 

REPORTS  OF  THE  METROPOLITAN  SEWERAGE  COMMISSION 


1.  Digest  of  Data  Collected  Before  the  Year  1908  Relating  to  the  Sanitary  Condi- 

tion of  New  York  Harbor;  87  pages;  1909; 

2.  Report  on  the  Discharge  of  Sewage  from  the  Proposed  Passaic  Valley  Sewer  of 

New  Jersey ;  7  pages ;  May  23,  1910 ; 

3.  Report  on  the  Proposed  Discharge  of  Sewage  from  the  Bronx  Valley  Sewer;  10 

pages;  July  25,  1910; 

4.  Sewerage  and  Sewage  Disposal  in  the  Metropolitan  District  of  New  York  and 

New  Jersey;  550  pages;  April  30,  1910; 

5.  Present  Sanitary  Condition  of  New  York  Harbor  and  the  Degree  of  Cleanness  which 

is  Necessary  and  Sufficient  for  the  Water ;  457  pages ;  August,  1912 ; 
Preliminary  Reports  on  the  Disposal  of  New  York's  Sewage : 

6.  I.    Study  of  the  Collection  of  the  Sewage  of  New  York  City  to  a  Central 

Point  for  Disposal;  16  pages;  September,  1911; 

7.  II.    Description  of  the  Four  Principal  Drainage  Divisions  in  that  Part  of  the 

Metropolitan  Sewerage  District  which  Lies  in  New  York  State;  11 
pages;  November,  1911; 

8.  III.    Study  of  the  Collection  and  Disposal  of  the  Sewage  of  the  Jamaica  Bay 

Division;  10  pages;  November,  1911; 

9.  IV.    Study  of  the  Collection  and  Disposal  of  the  Sewage  of  the  Upper  East 

River  and  Harlem  Division;  17  pages;  July,  1912; 

10.  V.    Study  of  the  Collection  and  Disposal  of  the  Sewage  of  the  Richmond  Divi- 

sion ;  21  pages ;  September,  1912 ; 

11.  VI.    Study  of  the  Collection  and  Disposal  of  the  Sewage  of  the  Lower  Hudson, 

Lower  East  River  and  Bay  Division ;  58  pages ;  January,  1913 ; 

12.  VII.    Critical  Reports  of  Dr.  Gilbert  J.  Fowler,  of  Manchester,  England,  and 

Mr.  John  D.  Watson,  of  Birmingham,  England,  on  the  Projects  of  the 
Metropolitan  Sewerage  Commission  with  Special  Reference  to  the  Plans 
Proposed  for  the  Lower  Hudson,  Lower  East  River  and  Bay  Division; 
33  pages;  February,  1913. 

13.  VIII.    Tidal  Currents  in  New  York  Harbor  as  Shown  by  Floats ;  46  pages ;  October, 

1913. 


762       REPORTS  OF  THE  METROPOLITAN  SEWERAGE  COMMISSION 

14.  IX.    Rainfall  and  the  Relations  Between  the  Volumes  of  Domestic  Sewage, 

Storm  Water  and  Tidal  Water  in  New  York  Harbor;  21  pages;  Novem- 
ber, 1913. 

15.  X.    Recommendation  for  a  Commission  to  Construct  a  System  of  Main  Drain- 

age and  Sewage  Disposal  for  New  York  and  Showing  the  Urgency 
Therefor;  7  pages;  January,  1914. 

16.  XI.    Discharge  of  Sewage  into  the  Harbors  of  Boston  and  New  York  and  a 

Report  by  X.  H.  Goodnough  on  the  Conditions  which  Led  to  the  Con- 
struction of  the  Main  Drainage  Systems  of  Boston  and  Vicinity;  21 
pages;  February,  1914. 

17.  XII.    Chemical  Oxidation  as  a  Process  of  Sewage  Treatment  and  a  Report  by 

Samuel  Rideal  on  Oxidation  Processes  Applicable  to  New  York  Condi- 
tions; 16  pages;  March,  1914. 

18.  XIII.    Purification  which  Can  be  Effected  by  Settling  Basins  and  a  Report  by 

Karl  Imhoff  upon  the  Use  of  Emscher  Tanks  in  Purifying  New  York 
Harbor;  21  pages;  March,  1914. 

19.  XIV.    Relation  Between  the  Disposal  of  the  Sewage  and  the  Death  Rate  and  a 

Report  by  Walter  F.  Willcox  on  the  Crude  and  Corrected  Death  Rates 
of  New  York,  London,  Berlin  and  Paris  for  the  Ten  Years  1900-1909; 
16  pages ;  March,  1914. 

20.  XV.    Digestion  of  Sewage  by  the  Harbor  Water  and  the  Exhaustion  of  Dissolved 

Oxygen,  with  Tables  of  Oxygen  and  Other  Chemical  Results;  161  pages; 
March,  1914. 

21.  XVI.    Form  of  Administration  Recommended  for  the  Protection  of  New  York 

Harbor  Against  Excessive  Sewage  Pollution;  12  pages;  March,  1914. 

22.  XVII.    Tidal  Information  in  Possession  of  the  Commission  and  Correspondence 

on  this  Subject  with  the  United  States  Coast  and  Geodetic  Survey;  70 
pages;  March,  1914. 


